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[R&D] Unlock Bootloaders

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mastamoon

Senior Member
Sep 17, 2010
2,871
3,417
Central NJ
If we can't put another phones boot loader on our phone because of a device Id mismatch, is it possible to spoof/change our device Id along with using their boot loader? I I would guess with the level of depth you guys are able to probe you might be able to do that sort of thing, maybe? ^_^

Sent from my SCH-I535 using Tapatalk 2
 
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xd.bx

Senior Member
May 14, 2011
431
292
I connected up with minicom and I was not able to talk to it at all. I received no response. So I decided to poke around a bit more on other things... It appears that QDL mode is like Qualcomm's version of Odin Download Mode.

I found a tool called "gobi_loader" which is supposed to communicate with this QDL mode. I'm running into a problem where it does not recognize the format of the firmware folder I am feeding it. I am trying to find out more about this.

This is some great news though. It could satisfy goal #1 as stated in the OP once we figure it out.

Hey,

Sorry to hear about the brick. Two pointers that could interest you:

- scotty2 bricked his Desire Z some time ago. He did not have the PBL at the time, nonetheless started implementing Qualcomm's download protocol. You can look at his sources here: https://github.com/tmzt/g2root-kmod/blob/master/scotty2/pbl/pbl.pl

- there is a closed source windows implementation of QDL in the RIFF Box. Il allows writing the flash for a number of HTC phones (they call it QHUSB). If you find an S-OFF HTC phone with the same chip as the Verizon S3, then you can dump the PBL through HTC secondary bootloader "mb" command.
 

Durthquake

Senior Member
Jun 9, 2010
84
28
Hey,

Sorry to hear about the brick. Two pointers that could interest you:

- scotty2 bricked his Desire Z some time ago. He did not have the PBL at the time, nonetheless started implementing Qualcomm's download protocol. You can look at his sources here: https://github.com/tmzt/g2root-kmod/blob/master/scotty2/pbl/pbl.pl

- there is a closed source windows implementation of QDL in the RIFF Box. Il allows writing the flash for a number of HTC phones (they call it QHUSB). If you find an S-OFF HTC phone with the same chip as the Verizon S3, then you can dump the PBL through HTC secondary bootloader "mb" command.

If this thought is not useful please remove - but isn't the One X us variant using the same S4 processor, and I believe it is unlocked (not sure if S-Off yet though?)
 

alquimista

Senior Member
Mar 20, 2008
218
118
Los Angeles
Here's Lime module built from the I535 kernel sources. This is for stock kernel.

https://www.dropbox.com/s/zdesybzfawlra0c/lime.ko

I now a have an 1.8 GB memory dump sitting on my laptop. It compresses nicely to 600 MB.

If you want the file, let me know.

Can we load lime.ko with the app posted here:
http://forum.xda-developers.com/showthread.php?t=1228605

It was built on an xperia s, but the dev asks for feedback on all devices.

Last, if that 1.8G dump contains no personal info, can you post it? I'd like to run it through IDA following ralekdev's instructions.

Offtopic:
How do you always have everything as soon as someone mentions it? It uncanny and amazing!

Ta,
ALQI

Sent from my SCH-I535 using xda app-developers app
 
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LLStarks

Senior Member
Jun 1, 2012
1,531
576
The module needs to be loaded with certain parameters, so I'm not sure if the app will help.

I don't want to post the dump since it has personal info.

PM me or ask on IRC.

(Alquimista, the Android build chain is awesome to have lying around.)
 
Last edited:

E:V:A

Inactive Recognized Developer
Dec 6, 2011
1,449
2,213
-∇ϕ
...
- scotty2 bricked his Desire Z some time ago. He did not have the PBL at the time, nonetheless started implementing Qualcomm's download protocol. You can look at his sources here: https://github.com/tmzt/g2root-kmod/blob/master/scotty2/pbl/pbl.pl

Awesome! He has many more goodies in there, like a modified kmem, for example. Anyway, those scripts are for the Qualcomm MSM7230, but we could try to modify it to our MSM8960. We just need to understand the Memory layout better. Below I have re-posted the scripts edited for compactness and reference.

pbl.pl (used to talk to the QDL HS-USB PBL downloader...)
Code:
[SIZE=2]#!/usr/bin/perl

# basic communications with the PBL Downloader that talks over usb if you've 
# totally effed up your phone (try fdisk_emmc from hboot if you want your phone 
# bricked to this state) 
# can upload a binary file to an address. (PBL allows 0x80000000 - 0x8003ffff)

use strict;
use warnings;
use Fcntl;
$| = 1;

my @crcTable = (0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf,
                0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7,
                0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e,
                0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876,
                0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd,
                0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5,
                0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c,
                0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974,
                0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb,
                0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3,
                0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a,
                0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72,
                0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9,
                0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1,
                0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738,
                0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70,
                0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7,
                0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff,
                0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036,
                0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e,
                0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5,
                0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd,
                0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134,
                0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c,
                0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3,
                0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb,
                0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232,
                0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a,
                0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1,
                0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9,
                0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330,
                0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78);

{
    my $retval;
    my $response;
    my ($fd, $tty) = setupTTY();
    
    if(!defined $fd) {
        print "Failed to find/open TTY.\n";
        exit 1;
    }
    print "Using TTY: $tty\n";

    if(!sendPacket($fd, deserialize("07"))) {
        print "Failed requestParam\n";
        exit 1;
    }
    if(!($response = readPacket($fd)))
    {
        print "Failed to read response.\n";
        exit 1;
    }
    print "Param: ", serialize($response), "\n";
    my $swver = getSoftwareVersion($fd);
    if(!defined $swver)
    {
        print "Failed to get software version\n";
        exit 1;
    }
    print "Version: $swver\n";

    for(0..255) {
        next if($_ == 5);       # execute
        next if($_ == 0xa);     # reset
        next if($_ == 0xe);     # power off

        my $cmd = pack('C', $_);
        my $response;
        exit 1 if(!sendPacket($fd, $cmd));
        exit 1 if(!($response = readPacket($fd)));
        my @responseBytes = unpack('C*', $response);
        next if(scalar @responseBytes == 3 && $responseBytes[2] == 6);
        print "Command ", sprintf('%.2x', $_), " response: ", serialize($response), "\n";
    }
}

sub writeChunk
{
    my $fd = shift;
    my $address = shift;
    my $chunk = shift;
    my $length = length($chunk);
    my $response;
    return undef if(!sendPacket($fd, deserialize("0f " . serial32($address) . " " . serial16($length) . " " . serialize($chunk))));
    return undef if(!($response = readPacket($fd)));

    my @responseBytes = unpack('C*', $response);
    return undef if(scalar @responseBytes != 1);
    return undef if($responseBytes[0] != 2);
    return 1;
}

sub uploadFile
{
    my $fd = shift;
    my $address = shift;
    my $filename = shift;
    local $/ = undef;

    return undef if(!open(FILE, $filename));
    my $data = <FILE>;
    close FILE;

    while(length $data) {
        my $chunk = substr($data, 0, 1024);
        my $restOfData = substr($data, length($chunk), length($data) - length($chunk));
        print "Writing ", length($chunk), " bytes to 0x", sprintf('%.8x', $address), "; ", length($restOfData), " bytes left.\n";
        return undef if(!writeChunk($fd, $address, $chunk));
        $address += length($chunk);
        $data = $restOfData;
    }
    return 1;
}

sub getSoftwareVersion
{
    my $fd = shift;
    my $response;
    return undef if(!sendPacket($fd, deserialize("0c")));
    return undef if(!($response = readPacket($fd)));
    return pack('C*', map { hex } split(/\s/, serialize(substr($response, 2))));
}

sub setupTTY
{
    my $tty;
    my $fd;
    my @usbDevices;
    my @usbBusses = map { (split(/\//, $_))[-1] } glob '/sys/bus/usb/devices/usb*';

    foreach my $bus (@usbBusses) {
        my ($busNum) = $bus =~ /usb(\d+)/;
        my @devices = grep /^\d+-\d+$/, map { (split(/\//, $_))[-1] } glob "/sys/bus/usb/devices/$bus/$busNum-*";
        next if(!scalar @devices);

        foreach my $device (@devices) {
            my $product = getFile("/sys/bus/usb/devices/$bus/$device/idProduct");
            my $vendor = getFile("/sys/bus/usb/devices/$bus/$device/idVendor");
        next if(!defined $product || !defined $vendor);
            if($vendor eq '05c6' && $product eq '9008') {       # it's us.
                my @drivers = grep /^$device:\d+\.\d+$/, map { (split(/\//, $_))[-1] } glob "/sys/bus/usb/devices/$bus/$device/$device:*";
                foreach my $driver (@drivers) {
                    my @ttys = map { (split(/\//, $_))[-1] } glob "/sys/bus/usb/devices/$bus/$device/$driver/tty*";
                    if(scalar @ttys == 1) { $tty = "/dev/$ttys[0]"; }
                }
             }
        }
    }

    if(defined $tty) {
        system "/bin/stty raw -iexten -echo < $tty";
        return undef if(!sysopen($fd, $tty, O_RDWR | O_SYNC));
        return ($fd, $tty);
    }
    return undef;
}

sub getFile {
    my $file = shift;
    local $/ = undef;
    return undef if(!open(FILE, $file));
    my $content = <FILE>;
    $/ = "\n";
    close FILE;
    chomp $content;
    return $content;
}

sub execute {
    my $fd = shift;
    my $address = shift;
    my $response;
    return undef if(!sendPacket($fd, deserialize("05 " . serial32($address))));
    return undef if(!($response = readPacket($fd)));
    return 1;
}

sub serialize {
    my $buffer = shift;
    return join(' ', map { sprintf('%.2x', $_) } unpack('C*', $buffer));
}

sub deserialize {
    my $buffer = shift;
    return pack('C*', map { hex } split(/\s+/, $buffer));
}

sub crcByte {
    my $crc = shift;
    my $c = shift;
    return (($crc >> 8) & 0xffff) ^ $crcTable[($crc ^ $c) & 0xff];
}

sub crc {
    my $crc     = shift;
    my $buffer  = shift;
    my @bytes   = unpack('C*', $buffer);    
    foreach(@bytes) { $crc = crcByte($crc, $_); }
    return ~$crc & 0xffff;
}

sub swap16 {
    my $short = shift;
    return (($short << 8) | ($short >> 8)) & 0xffff;
}

sub swap32 {
    my $long = shift;
    return (($long << 24) | (($long & 0xff00) << 8) | (($long & 0xff0000) >> 8) | ($long >> 24));
}

sub setupPacket {
    my $packet = shift;
    my $crc = swap16(crc(0xffff, $packet));
    return deserialize("7e " . serialize(escape($packet . deserialize(serial16($crc)))) . " 7e");
}

sub escape {
    my $buffer = shift;
    my @bytes = unpack('C*', $buffer);
    my @newBytes;

    foreach my $byte (@bytes) {
        if($byte == 0x7e) {
            push @newBytes, 0x7d;
            push @newBytes, 0x5e;
        }
        elsif($byte == 0x7d) {
            push @newBytes, 0x7d;
            push @newBytes, 0x5d;
        }
        else {
            push @newBytes, $byte;
        }
    }
    return pack('C*', @newBytes);
}

sub unescape {
    my $buffer = shift;
    my @bytes = unpack('C*', $buffer);
    my @newBytes;
    my $escape = 0;

    foreach my $byte (@bytes) {
        if($escape) {
            if($byte == 0x5e) {
                push @newBytes, 0x7e;
            }
            elsif($byte == 0x5d) {
                push @newBytes, 0x7d;
            }
            else {
                print "Fatal error unescaping buffer!\n";
                return undef;
            }
            $escape = 0;
        }
        else {
            if($byte == 0x7d) {
                $escape = 1;
            }
            else {
                push @newBytes, $byte;
            }
        }
    }
    return pack('C*', @newBytes);
}

sub serial16 {
    my $short = shift;
    my $lbyte = $short & 0xff;
    my $hbyte = $short >> 8;
    return sprintf('%.2x %.2x', $hbyte, $lbyte);
}

sub serial32 {
    my $long = shift;
    my $lshort = $long & 0xffff;
    my $hshort = $long >> 16;
    return serial16($hshort) . ' ' . serial16($lshort);
}

sub readPacket {
    my $fd = shift;
    my $byte;
    my $retval = sysread($fd, $byte, 1);
    if(!$retval) {
        print "retval: $retval\n";
        print "$!\n";
    }
    return undef if(!$retval);
    return undef if(unpack('C', $byte) != 0x7e);

    my @bytes;
    while(1) {
        $retval = sysread($fd, $byte, 1);
        if(!$retval) {
            print "retval (while): $retval\n";
            print "$!\n";
            return undef;
        }
        last if(unpack('C', $byte) == 0x7e);
        push @bytes, unpack('C', $byte);
    }

    my $buffer = unescape(pack('C*', @bytes));
#    print "RECEIVED: 7e " . serialize($buffer) . " 7e\n";
    @bytes = unpack('C*', $buffer);
    pop @bytes; pop @bytes;
    return deserialize(join(' ', map { sprintf('%.2x', $_) } @bytes))
}

sub sendPacket {
    my $fd = shift;
    my $buffer = shift;
#    print "SENDING: ", serialize(setupPacket($buffer)), "\n";
    my $retval = syswrite($fd, setupPacket($buffer), length(setupPacket($buffer)));
    if(!$retval) { print "$!\n"; }
    return undef if(!$retval);
    return 1;
}
[/SIZE]
dumppbl.pl (Used to dump PBL code...)
Code:
[SIZE=2]#!/usr/bin/perl

# dump the PBL, and the PBL Downloader from oemsbl. (probably requires radio s-off)

use strict;
use warnings;
use Fcntl;
$| = 1;

{
    my ($fd, $tty) = setupTTY();
    if(!defined $fd) {
        print "Failed to find/open TTY.\n";
        exit 1;
    }    
    print "Using TTY: $tty\n";
    print "Dumping PBL... (0xffff0000 - 0xffffffff)\n";
    dumpMemory($fd, [COLOR=Red][B]0xffff0000, 0x10000[/B][/COLOR], "pbl.bin");
    dumpMemory($fd, [COLOR=Red][B]0xfffe6000, 0xa000[/B][/COLOR], "pbl_download.bin");
}

sub dumpMemory {
    my $fd = shift;
    my $address = shift;
    my $length = shift;
    my $outfile = shift;
    print $fd "[COLOR=Red][B]mb [/B][/COLOR]" . sprintf('%x', $address) . " " . sprintf('%x', $length) . "\r\n";
    my @binary;
    while(<$fd>) {
        my ($line) = /^(.*)\r$/;
    last if(!length($line));
        my @bytes = split(/\s/, join('', $line =~ /^[^\:]+\: ((?:[0-9A-F]{2}\s){8})-\s((?:[0-9A-F]{2}\s){8})/));
        push @binary, @bytes;
        print "Received: ", scalar @binary, "\r";
    }
    print "\n";    
    my $output = pack('C*', map { hex } @binary);
    open OUTPUT, ">", $outfile or die;
    print OUTPUT $output;
    close OUTPUT;
}

sub setupTTY {
    my $tty;
    my $fd;
    my @usbDevices;
    my @devices = grep { !/\:/ && !/usb/ } map { (split(/\//, $_))[-1] } glob '[COLOR=Blue]/sys/bus/usb/devices/*[/COLOR]';
    foreach my $device (@devices) {
        my $product = getFile("[COLOR=Blue]/sys/bus/usb/devices/$device/idProduct[/COLOR]");
        my $vendor = getFile("[COLOR=Blue]/sys/bus/usb/devices/$device/idVendor[/COLOR]");      
    next if(!defined $product || !defined $vendor);
        if($vendor eq '[COLOR=Blue][B]05c6[/B][/COLOR]' && $product eq '[COLOR=Blue][B]900e[/B][/COLOR]') {  # it's us.
            my @drivers = grep /^$device:\d+\.\d+$/, map { (split(/\//, $_))[-1] } glob "/[COLOR=Blue]sys/bus/usb/devices/$device/$device:*[/COLOR]";           
            foreach my $driver (@drivers) {
                my @ttys = map { (split(/\//, $_))[-1] } glob "[COLOR=Blue]/sys/bus/usb/devices/$device/$driver/tty*[/COLOR]";
                if(scalar @ttys == 1) { $tty = "/dev/$ttys[0]"; }
            }
        }
    }
    if(defined $tty) {
        system "/bin/stty raw -iexten -echo < $tty";
        return undef if(!open($fd, '+<', $tty));
        return ($fd, $tty);
    }
    return undef;
}

sub getFile {
    my $file = shift;
    local $/ = undef;
    return undef if(!open(FILE, $file));
    my $content = <FILE>;
    $/ = "\n";
    close FILE;
    chomp $content;
    return $content;
}
[/SIZE]
These are Perl scripts, probably to be run using the SL4A (Scripting Layer for Android).
We need to edit the red parts for sure, and probably also the blue.
(Same for pbl.pl, but I didn't bother highlighting that code.)

EDIT: ----------------------------------------

Dang! Closer inspection, show that the dumppbl.pl script should perhaps be ran from the linux PC side?
And not only that, it has to be somehow running in the boot-loader mode so that the mb command is available...
I think this is a HTC specific command... I'm very confused! SORRY!
---------------

Could someone confirm and enlighten us??
 
Last edited:

xd.bx

Senior Member
May 14, 2011
431
292
Hi EVA,

So after reading again the boot process, it would appear that the PBL is in the RPM-ARM7 ROM, whereas SBL2/3 are loaded into Krait which is (afaik?) the main apps ARM processor. So unless the memory view from Krait is the same as RPM, the "mb" command probably won't work.(also, note the PBL resides at 0 according to manual, not the usual 0xFFFF0000). A better alternative, I think, would be to halt with JTAG the RPM-ARM7, then simply dump the PBL. Someone with a RIFF Box & a soldered JTAG could try it, it might work wonders. Then the PBL could be studied to better understand the boot process and possibly find vulns (think bootrom vulns as in the iDevices).
 

Rebellos

Senior Recognized Developer
May 13, 2009
1,353
3,427
Gdańsk
Somehow I cannot just ignore and stop thinking about this post:

"How to enable/disable the secure boot authentication feature on MSM8660 by using the JTAG"

The reason is that the MSM8660 is essentially the same as our MSM8960 apart some little quirks...(to be determined.)
Here is an edited summary:

NOTE:
a) This solution does not apply to all MSM8660 versions
b) This solution does not apply to the RPM JTAG disable cases
c) This solution only uses for debug purpose.

For some reasons, if you need to to run unsigned software on a secure boot
enabled (the AUTH_EN bit in SECURE_BOOT1 register is blown) MSM8660 chip, the
following instruction is able to disable the secure boot authentication by using
RPM-JTAG.

1. Launch the Daisy Chain RPM-JTAG shortcut (i.e modem_proc\tools\t32\DC7_ARM7_RPM).
2. Execute the cmm script which contain the following command:

Code:
[SIZE=2]system.option resbreak on[/SIZE]
[SIZE=2]system.up[/SIZE]
[SIZE=2]g [B]0x7ce8 [/B]/o /cmd "r.s r0 [B][COLOR=Red]0x0[/COLOR][/B]" ; [B]0x0 for disabling[/B] the secure boot authentication[/SIZE]
[SIZE=2]wait 1ms[/SIZE]
[SIZE=2]g[/SIZE]
Of course, you can simply modify the cmm script (listed below) to enable the
secure boot authentication without blowing SECURE_BOOT1 register on MSM8660 chip
by using RPM-JTAG or short the GPIO_76 pin.
Code:
[SIZE=2]system.option resbreak on[/SIZE]
[SIZE=2]system.up[/SIZE]
[SIZE=2]g [B]0x7ce8 [/B]/o /cmd "r.s r0 [COLOR=Red][B]0x1[/B][/COLOR]" ;    [B]0x1 for enabling[/B] the secure boot authentication[/SIZE]
[SIZE=2]wait 1ms[/SIZE]
[SIZE=2]g [/SIZE]
What is this command doing exactly?
My guess is that 0x7ce8 is an address, but for what?

I'm sorry if this has been already answered.
I'm not 100% sure about it but looks like it's:
Code:
restart->run until reaching 0x7CE8->set R0=0(or 1)->sleep 1ms (irrevelant)->resume
I'm nearly sure that 0x7CE8 is last OPcode of ROM bootloader's (PBL) function like
Code:
bool is_secure_boot();
And JTAG script does override its return value.
//edit3:

Or it's function loading code from solid memory to RAM and JTAG script is overriding it's parameter, telling if its secure or nonsecure boot
Thanks to RalekDev

Doing it like this will simply let PBL load and execute ANY code in place of SBL1, It'll even try jump into Nyan Cat if, of course, it passes non-secure integrity check (like md5/crc sum). It's still tethered boot, with JTAG and stuff.


//edit:

Hi EVA,

So after reading again the boot process, it would appear that the PBL is in the RPM-ARM7 ROM, whereas SBL2/3 are loaded into Krait which is (afaik?) the main apps ARM processor. So unless the memory view from Krait is the same as RPM, the "mb" command probably won't work.(also, note the PBL resides at 0 according to manual, not the usual 0xFFFF0000). A better alternative, I think, would be to halt with JTAG the RPM-ARM7, then simply dump the PBL. Someone with a RIFF Box & a soldered JTAG could try it, it might work wonders. Then the PBL could be studied to better understand the boot process and possibly find vulns (think bootrom vulns as in the iDevices).

Modern multicore SoCs does usually interconnect all cores busses, so any core can access any part of RAM memory (if TMZ or MMU doesn't disallow it, also some peripherials can be useable by just one specific core), however for eg. some memory bank can be addressed under 0x10000000 from MODEM-CPU and can be seen under 0x90000000 from APPS-CPU.
 
Last edited:

E:V:A

Inactive Recognized Developer
Dec 6, 2011
1,449
2,213
-∇ϕ
I'm sorry if this has been already answered.
I'm not 100% sure about it but looks like it's:
Code:
restart->run until reaching 0x7CE8->set R0=0(or 1)->sleep 1ms (irrevelant)->resume
I'm nearly sure that 0x7ce8 is last OPcode of ROM bootloader's (PBL) function like
Code:
bool is_secure_boot();

Roger that! I was working on that, and you Mr. Spock just beat me to it.
This is (Lauterbach or ARM DS-5) TRACE32 JTAG scripting code (CMM style) with
slight variations, depending on your debugging system. (There are many!)
That's why it took me so long to figure what that line was doing.

Code:
[SIZE=2]g [B]0x7ce8 [/B]/o /cmd "r.s r0 [/SIZE][SIZE=2][COLOR=Red]0x0[/COLOR][/SIZE][SIZE=2]" ;[/SIZE]
To make a very long story short. The important commands can be summarized as this.

Code:
[SIZE=2]-------------------------------------------------------------------------------
Command         Short           Description
-------------------------------------------------------------------------------
data.set        d.s              writes data to memory.
data.dump       d                displays 0x20 (default) bytes of data from a specific address (range).
register.set    r.s              sets the value of a register.
go              g                starts running the device.
system.up       sys.u            connects to the specified target.
system.down     sys.d            disconnects the debugger from the target.
break           b                stops running the target.
-------------------------------------------------------------------------------
[/SIZE]
Then I had trouble finding the "/cmd" flag, but it simply does what you said:
"CMD <string> Execute 1 or more TRACE32 commands when the breakpoint is hit."
As for the "/o" flag, I have no idea, and could not find any info, but we got the message without it!

So this raises two questions:
a) Does this map to the same location in the MSM8960 ?
b) What is the function of GPIO_76 in the MSM8660 ? (Same as in 8960?)

EDIT: BTW. What do you mean with "nearly sure"? Can you check and confirm?
What do you need to do so? (Or better yet, if someone can provide a binary or assembly dump...)

EDIT2 (2012-08-14):
The "/o" flag is probably short for "/Onchip" which sets an on-chip hardware break-point.
(There are usually only two available, unlike SW BP's which can be oo.)
 
Last edited:

Ralekdev

Retired Senior Recognized Developer
Sep 4, 2010
32
384
a) Does this map to the same location in the MSM8960 ?

For our phone it would need to be 0x8834.
That's the end of the function that checks if the secure boot bit is enabled, so by setting r0 to 0 you just force it to return false.

The specific value that determines whether secboot is on is at 0x706038 in memory, 5th bit (0x20). If set, secboot is on.
If this is not set, the PBL does not check the certificate chain and signature of SBL1, SBL1 doesn't check SBL2, etc.
This alone doesn't let you flash unsigned boot.img directly because our aboot does the signature check regardless of secboot, but since SBL3 would no longer check aboot's signature you can upload a patched aboot that skips the check

Unfortunately this is only really useful to people with JTAG or the knowledge to make the needed hardware modification.

As it stands, I don't see a way to disable secure boot through any software method, which is most certainly by design.
 

AdamOutler

Retired Senior Recognized Developer
Feb 18, 2011
5,224
9,811
Miami, Fl̨̞̲̟̦̀̈̃͛҃҅͟orida
right, unless we can load a kernel into memory somehow..

While ralekdev was looking at aboot he mentioned this to me in G+
f you can somehow manage to get a kernel image loaded to 0x88EFF000 aboot skips all checks

However, those of you who are decompiling and analyzing, please look for boolean or hexidecimal values in memory which control boot from SDCard or EMMC.. this is where we can begin hacking the hardware. It's logical to assume the special function registers (SFRs) are all located within the same block of memory. SFRs will appear to be a location in memory.

These SFRs tell the device where to boot from and they are tied directly to the resistors outside of the processor. These boolean values located in the SFRs are digital representations of highs and lows applied to pins on the processor. Though they are accessed the same way as the rest of the memory, they are actually digital inputs like GPIOs.

If we can locate these memory registers I can hook up via SSH, monitor the memory locations while probing and injecting highs and lows to look for changes. It may be possible to disable secure boot this way.
 

newuser134

Senior Member
Dec 18, 2009
286
92
Unfortunately this is only really useful to people with JTAG or the knowledge to make the needed hardware modification.

As it stands, I don't see a way to disable secure boot through any software method, which is most certainly by design.

Does anyone know the hardware modification required to disable secure boot? I'd be willing to try it and then try flashing a patched aboot to avoid software checks, if anyone can point out specific hardware modifications or resistors to connect/disconnect from certain pins, I'm assuming from the quoted post that secure boot can be disabled by doing some hardware modifications.
 

newuser134

Senior Member
Dec 18, 2009
286
92
Can you not read the post above yours?

Yes, but maybe I misunderstood. What I read from that post is that you can connect via SSH and set the specific memory for SFR's (by software), however, that you couldn't get software access yet since secure boot is on, but since not everyone might want to open their phone and make a hardware change, I was just wondering if it may be known which specific SFR'S might need to be set (mainly from Ralekdev's post above yours), by hardware change not by ssh or software, Ralekdev's post sounded like that might be known but it wouldn't do much good to the average owner since it couldn't be done unless by jtag or hardware modification. Kind of like you have jtag and aren't worried about flashing alternative aboot's even though the average owner wouldn't want to do that, so it wouldn't do them any good. I was just stating I wouldn't mind trying the hardware modifications to disable secure boot.

If I misunderstood, please remove the post, didn't mean to ask a pointless question, just wanted to volunteer to test if there was a known way even if not by software. Just excited to help testing to turn off secure boot.
 
Last edited:

The Archangel

Senior Member
Sep 2, 2010
6,191
3,716
Virginia beach
.

If you have to begin or end your post with "***delete * ||remove this post"don't post because we have to notify a moderator to come and delete it, then the moderator has to do it. So you end up not only wasting your own time, looking like a fool, but you also waste 2 others time and take up valuable space on a page.

To answer your question, you don't partition memory.


I need to put this in my signature, btw ill clean the crap up, again before I call it a night.
 
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  • 561
    Verizon GS3 is now Bootloader UNLOCKED.
    We now have access to an unsecure bootloader. This was leaked by an African-Canadian Sock Monkey.

    Let me make this clear. If Samsung updates your device's bootloaders, using this tool could potentially brick your device. Once you apply this, never accept a factory update without first flashing the Odin Packages in the Original Post of this thread. As a general rule, you want to be the last guy to apply any Samsung update. Run custom.

    As of the date of this posting, this works great on Linux and it should work wonderfully on Mac too. NOTE: this may work on windows, but please, windows users.. learn to use your computer before you ask questions on XDA-Developers. This is one-click on Linux and Mac every darn time. If you're using Windows, I recommend downloading Windows Ubuntu Installer(WUBI) to install Ubuntu from within Windows.

    Download
    http://d-h.st/ypJ


    Instructions:
    1. Open this file
    2. Select Root with DebugFSRoot and Do It
    3. Select Flash Unsecure Aboot and Do It
    4. Use Odin or CWM to flash kernels to your device

    1zqwmlc.png

    To flash from device without the above tool:
    • root your device
    • Download this link to your /sdcard/Downloads/ folder: http://d-h.st/Piq
    • Type this in the terminal emulator
      Code:
      su -c dd if=/sdcard/Downloads/aboot.img of=/dev/block/mmcblk0p5

    This was tested with a Sprint kernel flashed via Odin. Although the Sprint kernel caused the device to have a blank screen due to hardware incompatibility, it's more than enough for a proof-of-concept. Stock bootloaders will not let you flash improper kernels with Odin and will cause the device not to boot. This corrects the problem. I'll leave implementation to other developers. If you feel uncomfortable flashing this on your own, wait for your favorite kernel developer to release something.

    Note to developers: This CASUAL package contains everything you need. A jar can be opened as a zip file. CASUAL format sticks all scripts in the /SCRIPTS/ folder. You can obtain all files needed from within this package, then repackage them into CWM format. In order to avoid a mass brick fest, please apply an assert to your CWM scripts to verify ro.build.version.incremental and do not allow updates past what has been tested. As of the time of this writing I535VRALG7B is safe.

    With the unlock of the GS3, this thread is locked. There will be no victory dancing in here. Move along to General or something. This thread will lie dormant until it is needed again in the future. Ralekdev will be releasing another exploit in the future as soon as this one stops working. Feel free to review what was learned until then.

    P.S. Sorry to those who I have offended by having posts removed. I'm also sorry to those who had their intelligence insulted before I had both of our posts removed. I hope you understand that in 6 months from now when everyone forgets about this thread but needs to catch back up, the information will still be right here in condensed format.
    173
    Rules:
    Do not post in here unless you have something constructive to say. "Thanks", "Hey this is wonderful", and any other comments like that are not wanted. They take up space and make it more difficult to find information. I'm requesting that this thread be heavily moderated. In order to work efficiently, information density must be kept high. We are all guilty of adding in a few off-topic sentances from time-to-time, but this thread is strictly business and I expect the moderators to moderate me as well.

    What is this?
    This is the place where we can research and develop a method to unlock the bootloader of the Verizon Galaxy SIII. Hopefully, this will be development at its finest.


    Why not just buy a developer edition
    GTFO! Not a single person got started developing by buying a developer phone. They started developing because they were unhappy with the features of their device and wanted something better. They wanted something more. This developer phone is a tax on developer innovation. We do not stand for that. We will break the security and we will enable XDA-Developers to do what they do best.

    Until security is broken and available for everyone, this device will get updates last, users will be unhappy because there are no additional features and Samsung violates the spirit of Open Source and copyright laws. Take a look at the bottom line of GPL-Violations.org FAQ located here: http://gpl-violations.org/faq/sourcecode-faq.html


    What are the goals?
    • Attain a bootloader recovery - 75% JTAG (the extra 25% will be for a user-friendly method)
      The Galaxy S3 is bootable from SDCard. In case of emergency this is needed. We need to verify that this works on the Verizon GS3 to bring up Odin. This will set up infrastructure for research.
    • Attain a full stock restoration via Odin or Heimdall - 90%
      For use with Odin3.
      Bootloader - BOOTLOADER_I535VRALF2_618049_REV09_user_low_ship.tar.md5 - 1.97 MB - Thanks nbsdx
      PDA - SCH-I535_VZW_1_20120705143513_fti2qg2lmf.zip
      NEED CSC PACKAGE (MODEM, PARAMS and Other Miscellaneous partitions). This is enough to recover a device though.
      To include bootloaders and recovery to a working and stock condition with the EMMC wiped entirely. Heimdall is a work in progress for this device. This will complete the infrastructure needed for research.
    • Collect information
      This will be the longest and most difficult part of this development. The information provided by Qualcomm is not readily available. Samsung is notoriously secretive about their bootloaders. Mainly we, as a community, will generate information. Please post any relevant datasheets, theory-of-operation, or manuals which you can find.
    • Provide a way to remove security checks from Odin3.] 100% - insecure aboot.img which may break in the future
      By removing security checks from Odin3 on the computer or the Loki daemon on the device we can flash anything through Odin or Heimdall.
    • Provide a way to bypass security checks within bootloaders. 200% we have two exploits, only one has been released.
      This is the ultimate goal. Once we can bypass the security checks, kernels can be flashed giving us the control required to develop


    Initial information
    [BOOTLOADER] Locked bootloader research and news: http://forum.xda-developers.com/showthread.php?t=1756919


    My own research

    SBL1 is the first booting partition. Qualcomm provides the Modem partition so it comes first on the EMMC. SBL1 is the first bootloader and that is specified by Qualcomm standards. Qualcom mmake sthe primitive bootloader and allows their customers (Samsung) to make a Secondary bootloader. Samsung chose to use three secondary bootloaders.

    The following 0p* are located in /dev/block/mmcblk*

    0p1 = modem
    Built by se.infra
    HUDSON_GA_D2_USA-VZW-HARDKEY-PROD-USER
    I take this to mean this Qualcomm modem was built in Hudson Georgia.
    I was not able to find signatures on this block :). This does NOT mean that there are no signatures on this block. The file is 33 megs. The file is unencrypted.
    The modem uses the BLAST Kernerl ver : 02.04.02.02.00 Unfortunately we need someone who speaks French(???) to understand how this works http://blast.darkphpbb.com/faq.php
    Judging by the contents of this file, it is an operating system of it's own including keyboard, mouse and a lot of debugging information. We need to find out more about the BLAST Kernel and this partition.


    Samsung Proprietary partitions SBL1,2,3
    Overall I'm not entirely familiar with this new 3 SBL setup. If someone could help me out, that would be great. This 3 SBL setup looks like they tried to adapt (slopily) their IBL+PBL+SBL setup to the Qualcomm and added overhead.

    op2=sbl1
    This block is signed by Samsung, we will not be able to modify it.
    Some Strings we expect to see on UART are:

    0p3=sbl2
    This block is signed by Samsung, we will not be able to modify it.

    Some of the strings we may see over UART are:
    Code:
    RPM loading is successful.
    cancel RPM loading!
    SBL2, End
    SBL2, Delta
    .sbl2_hw.c
    sbl2_hw_init, Start
    sbl2_hw_init, Delta
    sbl2_hw_init_secondary, Start
    h/w version : %d
    sbl2_hw_init_secondary, Delta
    .SBL2, Start
    scatterload_region & ram_init, Start
    .scatterload_region & ram_init, Delta
    .sbl2_mc.c
    sbl2_retrieve_shared_info_from_sbl1, Start
    .sbl2_retrieve_shared_info_from_sbl1, Delta

    0p4=sbl3
    This block is signed by Samsung, we will not be able to modify it.

    Possibly useful information:
    SVC: R1-R14
    FIQ:R13-R14
    IRQ:R13-R14
    UND:R13-R14
    ABT:R13-R14
    SYS:R13-R14

    This block appears to be a full OS of its own. I'm not sure of its purpose.

    op5= aboot
    This block is signed by Samsung, we will not be able to modify it

    This block contains HTML information. It would appear that it is possible to put the device into a mode where it will provide a webserver which displays state information.

    This block appears to be a complete operating system

    This block contains the Loke Daemon which communicates with Odin3.


    0p6= rpm
    This block is signed by Samsung we will not be able to modify it

    0p7= boot
    This is the kernel. There are several things we can do here... I belive this package itself is not signed, but the zImage itself is... here is the bootimg.cfg file

    Code:
    [email protected]:~/Desktop/VZWGS3$ cat ./bootimg.cfg 
    bootsize = 0xa00000
    pagesize = 0x800
    kerneladdr = 0x80208000
    ramdiskaddr = 0x81500000
    secondaddr = 0x81100000
    tagsaddr = 0x80200100
    name = 
    cmdline = console=null androidboot.hardware=qcom user_debug=31

    It may be possible to use that cmdline variable as an exploit.




    0p8= tzTrust Zone
    0p9= pad
    0p10= param -boot mode parameters - this could be a potential exploitation point.
    0p11= efs -serial numbers
    I've honestly got no clue about most of the following partitions.
    0p12= modemst1
    0p13= modemst2
    0p14= system - Android stuff
    0p15= userdata - App Stuff
    0p16= persist
    0p17= cache - Storage for updates
    0p18= recovery - recovery partition
    0p19= fota
    0p20= backup
    0p21= fsg
    0p22= ssd
    0p23= grow

    External UART log from initial power up:
    Code:
    [1630] AST_POWERON
    [    0.000000] heap->name mm, mb->start c0000000
    [    0.000000] Reserving memory at address ea000000 size: 100000
    [    0.000000] sec_dbg_setup: [email protected]
    [    0.000000] sec_dbg_setup: secdbg_paddr = 0x88d90004
    [    0.000000] sec_dbg_setup: secdbg_size = 0x40000
    [    0.000000] etb_buf_setup: [email protected]
    [    0.000000] etb_buf_setup: secdbg_paddr = 0x8fffb9c0
    [    0.000000] etb_buf_setup: secdbg_size = 0x4000
    [    0.174515] rdev_init_debugfs: Error-Bad Function Input
    [    0.174881] AXI: msm_bus_fabric_init_driver(): msm_bus_fabric_init_driver
    [    0.176957] sec_debug_init: enable=0
    [    0.177475] ec_debug_nit: restrt_reason: 0xdf0085c
    [    .216358] msm8960_iit_cam:292]settingdone!!
    [    0.25006] i2c 2c-14: Inalid 7-bi I2C addrss 0x00
        0.25237] i2c ic-14: Can' create evice at x00
    [   0.252220]i2c i2c-1: Failed o registeri2c clien cmc624 t 0x38 (-6)
    [    .252250] 2c i2c-19:Can't crete deviceat 0x38
        0.25433] rdevinit_debufs: Error-ad Functin Input
        0.25222] max892 19-006: DVS mode disabledbecause VD0 and VI1 do not ave prope control.
    [    0.79536] ms_etm msm_tm: ETM tacing is ot enable beacaussec_debug s not enaled!
    [   0.284449 smd_chanel_probe_orker: alocation tble not iitialized
                                                                      [    0.38766] pm_untime: fil to wak up
    [   0.362032]hdmi_msm dmi_msm.1 externalcommon_stte_create sysfs grup de39e68                                                                   
    [    0362673] Iside writback_drivr_init                                                                                                         
    [   0.36275] Insidewritebackprobe                                                                                                               
    [    1.244803] TZCOM: unable to get bus clk                                                                                                     
    [    1.431680] cm36651_setup_reg: initial proximity value = 3                                                                                   
    [    1.549671] msm_otg msm_otg: request irq succeed for otg_power                                                                               
    [    1.566702] mms_ts 3-0048: [TSP] ISC Ver [0xbb] [0x20] [0x20]                                                                                
    [    1.571341] mms_ts 3-0048: [TSP] fw is latest. Do not update.                                                                                
    [    1.583488] [__s5c73m3_probe:3818] S5C73M3 probe                                                                                             
    [    1.587089] [s5c73m3_sensor_probe_cb:3793] Entered                                                                                           
    [    1.591942] [s5c73m3_i2c_probe:3675] Entered                                                                                                 
    [    1.596123] [s5c73m3_init_client:3381] Entered                                                                                               
    [    1.600579] [s5c73m3_i2c_probe:3695] Exit                                                                                                    
    [    1.604608] [s5c73m3_sensor_probe:3726] Entered                                                                                              
    [    1.609095] [s5c73m3_spi_init:226] Entered                                                                                                   
    [    1.613154] [s5c73m3_spi_probe:191] Entered                                                                                                  
    [    1.617335] [s5c73m3_spi_probe:201] s5c73m3_spi successfully probed                                                                          
    [    1.623561] [s5c73m3_sensor_probe :  3749] Probe_done!!                                                                                      
    [    1.672638] mmc0: No card detect facilities available                                                                                        
    [    1.682984] aat1290a_led_probe : Probe                                                                                                       
    [    1.693850] msm_soc_platform_init                                                                                                            
    [    1.697298] msm_afe_afe_probe                                                                                                                
    [    1.843064] msm_asoc_pcm_new                                                                                                                 
    [    1.849748] msm_asoc_pcm_new                                                                                                                 
    [    2.023134] set_dload_mode <1> ( c00176d4 )                                                                                                  
    [    2.052220] cypress_touchkey 16-0020: Touchkey FW Version: 0x06                                                                              
    [    2.123851] init: /init.qcom.rc: 466: invalid command '/system/bin/log'                                                                      
    [    2.129620] init: /init.qcom.rc: 573: ignored duplicate definition of service 'sdcard'                                                       
    [    2.137402] init: /init.qcom.rc: 586: ignored duplicate definition of service 'ftm_ptt'                                                      
    [    2.145490] init: /init.target.rc: 73: ignored duplicate definition of service 'thermald'                                                    
    [    2.154677] init: could not open /dev/keychord                                                                                               
    [    2.239951] init: Device Encryption status is (0)!!                                                                                          
    [    2.243705] init: [disk_config] :::: fsck -> /dev/block/mmcblk0p15 (ext4):::::                                                               
    [    2.251823] init: [disk_config] ext_check -> /system/bin/e2fsck -v -y /dev/block/mmcblk0p15                                                  
    [    2.588921] init: [disk_config] ext_check ->ok                                                                                               
    [    2.611597] init: [disk_config] :::: fsck -> /dev/block/mmcblk0p17 (ext4):::::                                                               
    [    2.617762] init: [disk_config] ext_check -> /system/bin/e2fsck -v -y /dev/block/mmcblk0p17                                                  
    [    2.655333] init: [disk_config] ext_check -> ok                                                                                              
    [    2.664947] init: [disk_config] :::: fsck -> /dev/block/mmcblk0p11 (ext4):::::                                                               
    [    2.671081] init: [disk_config] ext_check -> /system/bin/e2fsck -v -y /dev/block/mmcblk0p11                                                  
    [    2.704532] init: [disk_config] ext_check -> ok                                                                                              
    [    3.259056] init: cannot find '/system/etc/install-recovery.sh', disabling 'flash_recovery'                                                  
    [    3.270471] init: cannot find '/system/bin/dmbserver', disabling 'dmb'

    External UART log from battery-pull and reinsert
    Code:
    [1630] AST_POWERON
    [    0.000000] heap->name mm, mb->start c0000000
    [    0.000000] Reserving memory at address ea000000 size: 100000
    [    0.000000] sec_dbg_setup: [email protected]
    [    0.000000] sec_dbg_setup: secdbg_paddr = 0x88d90004
    [    0.000000] sec_dbg_setup: secdbg_size = 0x40000
    [    0.000000] etb_buf_setup: [email protected]
    [    0.000000] etb_buf_setup: secdbg_paddr = 0x8fffb9c0
    [    0.000000] etb_buf_setup: secdbg_size = 0x4000
    [    0.174484] rdev_init_debugfs: Error-Bad Function Input
    [    0.174851] AXI: msm_bus_fabric_init_driver(): msm_bus_fabric_init_driver
    [    0.176926] sec_debug_init: enable=0
    [    0.177445] sc_debug_iit: restat_reason  0xdf0086c
    [    0216206] [sm8960_int_cam:299]setting one!!
    [   0.217915 select_req_plan:ACPU PVS:Nominal
        0.25206] i2c ic-14: Invaid 7-bit 2C addres 0x00
    [   0.25207] i2c i2-14: Can'tcreate deice at 0x0
    [    0252250] 2c i2c-19 Failed t register 2c clientcmc624 at0x38 (-16
    [    0252250] ic i2c-19: an't creae device t 0x38
    [   0.25243] rdev_iit_debugs: Error-Bd Functio Input
    [   0.25292] max895 19-0060:DVS modesdisabled ecause VI0 and VID do not hve propercontrols.
                                                                                               [    0.29536] msmetm msm_em: ETM trcing is nt enable!
    [    0.35797] pm_rntime: fal to wakeupllcation tale not intialized
    [    .362093] dmi_msm hmi_msm.1:external_ommon_stae_create:sysfs grop de39e60                                                                   
    [    0.62734] Inide writeack_driverinit                                                                                                         
    [   0.36285] Inside riteback_robe                                                                                                               
    [    1.244803] TZCOM: unable to get bus clk




    possible exploitations
    Possible entry point MODEM - Someone with a JTAG setup test viability of modifying a single byte on /dev/block/mmcblk0p1
    Possible entry point PARAMS - Samsung stores their boot parameters in PARAMS partition. It may be possible to modify PARAMS for insecure boot
    Possible entry point BOOT - Modify CMDLINE parameter to load information from another location.
    Possible entry point BOOT - We may be able to shove an insecure bootloader into memory, boot into that, and then use the recovery partition as our kernel partition. Bauwks 2nd U-Boot. U-Boot is available for the Exynos 4412, we need to find one for Qualcomm.
    Possible entry point SYSTEM - It may be possible to use a 2nd init hack from this partition to load custom kernels into memory and reboot the kernel.


    Current tasks
    What do all of these partitions do?
    Do we have a SDCard based recovery?
    Where can we find an Odin3 CSC Flash?
    Testing methods above is required
    96
    I have heard, but do not know, that there may be plans to get one of the developer phones into Adam's hands to extract from. That may provide insight into how to disable Qualcomm Secure Boot no? Anyone care to shed some light on if this is still planned or not? Thanks

    I don't need another device. I want all of the partitions from a developer device and I'd like to work with someone who has one. Remote access via "WirelessADB" and the device set to be in the "DMZ" of a router would be sufficient for all tests I would need to do.

    Just as an update, I'm slowly getting back to work. For those who were wondering, I packed up everything and moved. I have my stuff 90% set up. I'm just getting back on it. I'm working on compiling all of the Verizon GS3 exploits into a single CASUAL one-click package. Root, recovery, Busybox, Basic Hacking Tools.

    Once I've got a CASUAL package put together I'll go through and read this thread again from start to finish and figure out what needs work... my mind is totally off-topic right now after a move. Time to get back to work. I hope to have some big news at the end of next week.
    85
    It's been a few days so I wanted to give an update on the signature check on boot.img

    As has been previously guessed, everything important in boot.img is included in the signature check

    page_size is always 0x800 since we're using emmc boot

    hash_size = 0x800 (read the first page with the boot_img_header)
    hash_size += page_size * ((page_size + ramdisk_size - 1) / page_size)
    hash_size += page_size * ((page_size + kernel_size - 1) / page_size)
    hash_size += page_size * ((page_size + second_size - 1) / page_size)

    For the stock boot.img, this should come out to be 0x573000, so the first 0x573000 bytes in boot.img are checked.

    These bytes are then SHA1 hashed and passed to the verification function

    After hash_size bytes is a series of 0x100 byte blocks that will be passed to the verification function (img_sig_data parameter below)

    The verification function uses the following structure

    Code:
    struct sig_ctx_t {
    	int count;
    	int seed[65];
    	int subcheck_seed[64]; // possibly a modulus
    }

    This sig_ctx is located in aboot.img at file offset 0x12642C in VRALF2 and VRALG1 (It'll start with bytes 0x40, 0x00, 0x00, 0x00)

    I've cleaned up the first function a bit from what IDA/Hex-Rays spit out, but the second function I haven't simplified as much

    Code:
    int signature_check_data(sig_ctx_t *sig_ctx, char *img_sig_data, signed int signature_len, char *sha1_of_contents) {
    
    	int* img_ofs_0x100 = (int*)(img_sig_data + 0x100);
    	int* img_ofs_0x200 = (int*)(img_sig_data + 0x200);
    	int* img_ofs_0x300 = (int*)(img_sig_data + 0x300);
    	int* img_ofs_0x400 = (int*)(img_sig_data + 0x400); // Temporary storage
    
    	// Copy 0x0 block to 0x100
    	memcpy(img_ofs_0x100, &img_sig_data[0], signature_len);
    
    	// ofs_0x200 is filled with byte-swapped ints from img_ofs_0x100
    	for (int i = 0; i < sig_ctx->count; i++) {
    		img_ofs_0x200[i] =  htonl(img_ofs_0x100[sig_ctx->count - 1 - i]);
    	}
    
    	// subcheck(sig_block *block, int *output, int *input1, int *input2)
    	// multiplication maybe?
    	signature_subcheck(sig_ctx, img_ofs_0x300, img_ofs_0x200, sig_ctx->subcheck_seed);
    	signature_subcheck(sig_ctx, img_ofs_0x400, img_ofs_0x300, img_ofs_0x300);
    	signature_subcheck(sig_ctx, img_ofs_0x300, img_ofs_0x400, img_ofs_0x200);
    
    	if ( sig_ctx->count )
    	{
    		count_minus_1 = sig_ctx->count - 1;
    		v18 = img_ofs_0x300[sig_ctx->count - 1];
    		v19 = sig_ctx->seed[sig_ctx->count]; // seed[64]
    		// v19 = *(&sig_ctx->count + sig_ctx->count + 1);
    		if ( v18 >= v19 )
    		{
    			if ( v18 == v19 )
    			{
    				for (int i = 0; i < sig_ctx->count; i++) {
    					int v22 = img_ofs_0x300[sig_ctx->count - 1 - i];
    					int v23 = sig_ctx->seed[sig_ctx->count - 1 - i];
    					if (v22 < v23) {
    						goto LABEL_18
    					}
    				}
    			}
    			if ( sig_ctx->count > 0 )
    			{
    				int carry = 0;
    				for (int i = 0; i < sig_ctx->count; i++) {
    					uint64 temp = img_ofs_0x300[i] - (uint64)sig_ctx->seed[i + 1];
    					img_ofs_0x300[i] = img_ofs_0x300[i] - sig_ctx->seed[i + 1] + carry;
    					carry = (int)(temp >> 32); // get high 32 bits
    				}
    			}
    		}
    
    		LABEL_18:
    		// Store the calculation back into img_ofs_0x100
    		for (int i = 0; i < sig_ctx->count; i++) {
    			int val = img_ofs_0x300[sig_ctx->count - 1 - i];
    			char* dest = &img_ofs_0x100[i];
    
    			dest[0] = (val & 0xFF000000) >> 24;
    			dest[1] = ((val & 0x00FF0000) >> 16) & 0xFF;
    			dest[2] = ((val & 0x0000FF00) >> 8) & 0xFF;
    			dest[3] = (val & 0xFF);
    		}
    
    		if (memcmp(img_ofs_0x100, sig_check_compare_result, 236)) // sig_check_compare_result is a char[236] with the first 2 bytes 0x00, 0x01, and the rest 0xFF
    			return 0;
    
    		if (signature_len > 236) {
    			if (memcmp(&img_ofs_0x100[236], sha1_of_contents, signature_len - 236)) // 256-236 = 20
    				return 0;
    
    			// Signature passed
    			return 1;
    		}
    	}
    	return 0;
    }


    Here's the subcheck function, it looks like arbitrary-precision math, possibly mulmod

    Code:
    void __fastcall signature_subcheck(sig_ctx_t *sig_data, int *output, int *input1, int *input2)
    {
      int v5; // [email protected]
      int count; // [email protected]
      unsigned __int64 v7; // [email protected]
      unsigned __int64 v8; // [email protected]
      int inner_index; // [email protected]
      int block1_pos; // [email protected]
      int v11; // [email protected]
      __int64 v12; // [email protected]
      int v13; // [email protected]
      unsigned __int64 v14; // [email protected]
      int v15; // [email protected]
      int v16; // [sp+18h] [bp-48h]@6
      unsigned int v17; // [sp+1Ch] [bp-44h]@6
      int outer_index; // [sp+2Ch] [bp-34h]@5
    
      if ( sig_data->count > 0 )
      {
        v5 = 0;
        do
        {
          output[v5++] = 0;                         // this do while is just memset(output, 0, 4 * sig_data->count)
          count = sig_data->count;
        }
        while ( sig_data->count > v5 );
        if ( count > 0 )
        {
          outer_index = 0;
          do
          {
            v16 = input1[outer_index];
            v7 = (unsigned int)v16 * (unsigned __int64)(unsigned int)*input2 + (unsigned int)*output;// v7 = input1[outer_index] * (uint64)input2[0] + output[0]
            v17 = sig_data->seed[0] * v7;
            v8 = sig_data->seed[1] * (unsigned __int64)v17 + (unsigned int)v7;
            if ( count <= 1 )
            {
              block1_pos = 1;
            }
            else
            {
              inner_index = 0;
              block1_pos = 1;
              do
              {
                v7 = (unsigned int)v16 * (unsigned __int64)(unsigned int)input2[block1_pos]
                   + (unsigned int)output[block1_pos]
                   + HIDWORD(v7);
                v8 = sig_data->seed[inner_index + 2] * (unsigned __int64)v17 + HIDWORD(v8) + (unsigned int)v7;
                ++block1_pos;
                output[inner_index] = v8;
                ++inner_index;
              }
              while ( block1_pos < sig_data->count );
            }
            output[block1_pos - 1] = HIDWORD(v8) + HIDWORD(v7);
            if ( (HIDWORD(v8) + (unsigned __int64)HIDWORD(v7)) >> 32 )
            {
              if ( sig_data->count <= 0 )
                return;
              v11 = 0;
              v12 = 0LL;
              v13 = 0;
              do
              {
                v14 = (unsigned int)output[v11] - (unsigned __int64)sig_data->seed[v11 + 1];
                v15 = output[v11] - sig_data->seed[v11 + 1];
                output[v11] = output[v11] - sig_data->seed[v11 + 1] + v12;
                count = sig_data->count;
                ++v13;
                ++v11;
                v12 = (signed int)((__PAIR__(HIDWORD(v14), v15) + v12) >> 32);
              }
              while ( v13 < sig_data->count );
            }
            else
            {
              count = sig_data->count;
            }
            ++outer_index;
          }
          while ( outer_index < count );
        }
      }
    }


    The goal is to make it so that after all the calculations the 256 byte block located at img_sig_data+0x100 has the contents 0x00, 0x01, 0xFF * 236, and then the sha1 of our boot.img

    I'm in the middle of moving at the moment, so I don't have as much time as I would like to look at this right now, but that should clear up in a few days.

    Also, if there's any interest I can post a guide on how to get the bootloader files loaded into IDA for analysis. Some knowledge of ARM assembly would be required though.

    EDIT:

    In other news, I found what keeps resetting the 16 byte encrypted romtype in param.img. It's libcordon.so, which is from /system/app/SysScope.apk (it'll also be copied to /system/lib/libcordon.so). It's using quite a few checks to see if you've modified your system.

    There's an adb scanner, checking to see if you've changed the ro.secure or ro.debuggable props.

    The root process scanner checks running processes and returns true if any are found running as root that are not one of:
    "debuggerd", "init", "installd", "servicemanager", "vold", "zygote", "netd", "ueventd", "dock_kbd_attach", "pppd", "pppd_runner", "mpdecision", "thermald", "hdmid", "sec_keyboard", "seccmmond", "mfsc", "mfdp"

    There's also a partition check, kernel checker, su scanner, and a file scanning mechanism using data from a sqlite db

    So to completely remove the Samsung custom screen on bootup and 5 second delay you'd need to disable the SysScope.apk, then encrypt and write the 16 bytes yourself using 0xFF000000 as the first int to mark yourself as official
    70
    A gentleman named Lee contacted me via email. He said he has 0 posts so he could not post in here. This post contains his email to me. I am not wrapping it in quotes because quotes are destroyed in future posts. This is literally the best development we've had in this thread.



    ------email from Lee------
    I've been looking at the bootloader in aboot.img the past day or so and wanted to contribute what I know about the param.img partition and how it's used. I've been following the thread at xda, but since my account has 0 posts I can't actually post this in that thread.

    Please note these are a little rough around the edges, just things I jotted down while reverse engineering.

    param.img Structure

    At offset 0 there's an 88 byte structure I've called the header

    struct param_header {
    int status; // need to investigate more. some relationships between this and boot modes. 4 == firmware error int unk_04; // haven't seen this used anywhere int unk_08; // haven't seen this used anywhere int emmc_checksum_attempted; int emmc_checksum_ok; int nvdata_backup; // says whether we have a backup of modemst1 in "fsg" partition and a backup of modemst2 in "backup" partition?
    int unk_18[16]; // haven't seen this used anywhere };

    status (NEEDS WORK):
    1 = ?
    2 = boot_mode 3?
    3 = recovery?
    4 = boot_mode 1 - fastboot. displays "firmware update issue" image
    5 = boot_mode 4?


    at offset 0x900000 there's a structure controlling some debug variables

    struct param_debug {
    int debug_level;
    int unk_04; // 4 in dumps. haven't seen this used anywhere int unk_08; // 0 in dumps. haven't seen this used anywhere int emmc_checksum_attempted; // mirror of param_header.emmc_checksum_attempted
    int emmc_checksum_ok; // mirror of param_header.emmc_checksum_ok };

    About param_debug.debug_level:
    It has 3 possible values, and it changes some flags are passed to the kernel.
    DLOW is the default, but some features like ramdump mode only work on DMID or DHIG

    1. 0x574F4C44 (DLOW) - Low debug setting strcat(boot_img_hdr->cmdline, " androidboot.debug_level=0x4f4c");// OL strcat(boot_img_hdr->cmdline, " sec_debug.enable=0"); strcat(boot_img_hdr->cmdline, " sec_debug.enable_user=0");

    2. 0x44494D44 (DMID) - Mid-level debugging strcat(boot_img_hdr->cmdline, " androidboot.debug_level=0x494d");// IM strcat(boot_img_hdr->cmdline, " sec_debug.enable=1"); strcat(boot_img_hdr->cmdline, " sec_debug.enable_user=0");

    3. 0x47494844 (DHIG) - Full debugging
    strcat(boot_img_hdr->cmdline, " androidboot.debug_level=0x4948");// IH strcat(boot_img_hdr->cmdline, " sec_debug.enable=1"); strcat(boot_img_hdr->cmdline, " sec_debug.enable_user=1"); strcat(boot_img_hdr->cmdline, " slub_debug=FPUZ");

    Check drivers/misc/sec_misc.c for what these values do for the kernel


    At offset 0x9FFC00 (sizeof(param.img) - 0x400 is how the offset is calculated by the BL):
    Here are 16 bytes unique to each device, and they are part of what determines whether or not you have a custom rom.

    It's AES128 encrypted using a key made from the emmc's psn and some static data

    Key generation:
    First, the 4byte psn is expanded to 8 bytes

    char first_half[14];
    snprintf(first_half, 13, "%08x", mmc_get_psn()); memcpy(aes_initial_key, first_half, 8);

    The second half is calculated based on all static data

    char custom_check_index_shuf_table[] = { 1, 3, 2, 4, 5, 1, 0, 4, 4, 5, 4, 0 }; char custom_check_table[] = { 0x40, 0x74, 0x25, 0x61, 0x21, 0x74, 0x70, 0x62, 0x62, 0x24, 0x33, 0x5E }; char romtype_enc_key_buf[32];

    char* custom_check_shuffle_calc(signed int always_199, int count) { int out_index; // [email protected] int last_index; // [email protected] int odd_index; // [email protected] int table_index; // [email protected] char table_value;

    if ( count <= 0 )
    {
    out_index = 0;
    }
    else
    {
    out_index = 0;
    last_index = 0;
    do
    {
    odd_index = always_199 & 1;
    always_199 >>= 1;
    table_index = odd_index + 2 * last_index; table_value = custom_check_table[table_index]; last_index = custom_check_index_shuf_table[table_index];
    romtype_enc_key_buf[out_index++] = table_value; } while ( out_index != count ); } romtype_enc_key_buf[out_index] = 0; return romtype_enc_key_buf; }

    This function is used like this (the parameters are always 199 and 8 in the vzw aboot):
    char* second_half = custom_check_shuffle_calc(199, 8); memcpy(&aes_initial_key[8], second_half, 8);

    Now we have 16 bytes in aes_initial_key, but it's shuffled again with the following function

    char custom_check_final_index_table[] = { 0, 4, 5, 0xD, 3, 8, 0xE, 9, 0xA, 2, 1, 7, 0xB, 6, 0xC, 0xF }; void custom_check_shuffle_final_key(char *iv, char *final) { int v2; // [email protected] int v5; // [email protected]

    v2 = 0;
    do
    {
    final[custom_check_final_index_table[v2]] = iv[v2];
    v2++;
    }
    while ( v2 != 16 );
    v5 = 0;
    do
    {
    final[custom_check_final_index_table[v5]] = iv[v5] ^ final[v5];
    v5++;
    }
    while ( v5 != 16 );
    }

    char aes_final_key[16];
    custom_check_shuffle_final_key(aes_initial_key, aes_final_key);

    This final key should be able to decrypt the 16 bytes

    The first 4 decrypted bytes cast to an int will be 0xFF000000 if you're running an official rom, or 0xEE000000 if you've flashed something custom If it's 0xEE000000 then you will be shown the "Custom" boot screen with the padlock on it, and it also causes a call to mdelay(5000) before actually booting the kernel.
    I've also seen 0xCC000000 mentioned in debug prints, causing it to print the device status as "Scanning" instead of "Official" or "Custom"


    Unfortunately this doesn't seem to help much with the boot.img check, but I've found where that is and am reversing it now.


    ----------------------------------------------------------------------------------------------------------------------------------------------------------------

    DDI Data
    Here's where the values like the flash count are stored (sometimes this might be called triangle state?) It's stored at 0x3FFE00 on the mmc

    struct ddi_data {
    int magic; // must be 0x12340012
    int custom_flash_count;
    int odin_count;
    int binary_type; // 0 = samsung official, 1 = custom, 2 = "Unknown"
    char model_name[16];
    int rom_type; // this is the first 4 bytes of the decrypted 16 bytes in the param partition. 0xFF000000 = samsung, 0xEE000000 = custom }


    ----------------------------------------------------------------------------------------------------------------------------------------------------------------

    Reboot Reason

    Values and effects for the reboot reason stored at 0x2A03F65C

    0x12345671 - ?
    0x12345678 - Normal mode


    0x77665500 - FASTBOOT_MODE. displays "downloading" boot image
    0x77665501 - ? seen checked but haven't found it used anywhere
    0x77665502 - RECOVERY_MODE. sets param_header.state to 3
    0x77665503 - sets param_header.state to 4. haven't seen it actually used

    0x77665507 - display the "not authorized" picture

    if ((reason & ~0xF) == 0x77665510) then they're commands for manipulating the nvdata I wouldn't play around with these unless you really know what you're doing All of them reboot the device into the normal mode except 0x77665515

    0x77665511 - copy modemst1 to fsg partition and copy modemst2 to backup partition. sets param_header.nvdata_backup to 1
    0x77665512 - copy fsg to modemst1 and copy backup to modemst2. checks to ensure param_header.nvdata_backup=1 first
    0x77665514 - erase fsg and backup partitions. clears param_header.nvdata_backup
    0x77665515 - same as 0x77665511 but then reboots the device into RECOVERY_MODE


    0x776655EE - RAMDUMP_MODE (only valid if param_debug.debug_level is DMID/DHIG)


    0xABCD4F4C - set param_debug.debug_level to DLOW 0xABCD494D - set param_debug.debug_level to DMID
    0xABCD4948 - set param_debug.debug_level to DHIG

    ----------------------------------------------------------------------------------------------------------------------------------------------------------------

    boot_type INCOMPLETE
    1 = fastboot
    2 = ramdump mode
    3 = recovery. resets param_debug
    4 = ?


    ----------------------------------------------------------------------------------------------------------------------------------------------------------------

    USB Flags INCOMPLETE

    0xF00 - jig mask
    0x100 - put the device into factory mode
    0x400 - change "console" boot parameter to "console=ttyHSL0,115200,n8%s" where %s is replaced by whatever was originally after "console="

    ----------------------------------------------------------------------------------------------------------------------------------------------------------------

    ODIN

    In addition to the ODIN/LOKE handshake sequence I saw in heimdall, there are 2 more in the S3.
    Send "FPGM" and you should get a response of "OK". It functions exactly as the ODIN/LOKE sequence.
    Send "ROOTING" and it responds with the current DDI data and terminates.

    -Lee