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Update from Feb 17th:
Samsung has started to upgrade eMMC firmwares on the field - only for GT-I9100 for now.
See post #79 for additional details.

Update from Feb 13th:
If you want to dump the eMMC's RAM yourself, go ahead to post #72.
I'm looking for a dump of firmware revision 0xf7 if you've got one.

Since it's very likely that the recent eMMC firmware patch by Samsung is their patch for the "sudden death" issue, it would be very nice to understand what is really going on there.

According to a leaked moviNAND datasheet, it seems that MMC CMD62 is vendor-specific command that moviNAND implements.
If you issue CMD62(0xEFAC62EC), then CMD62(0xCCEE) - you can read a "Smart report". To exit this mode, issue CMD62(0xEFAC62EC), then CMD62(0xDECCEE).

So what are they doing in their patch?

1. Whenever an MMC is attached:
a. If it is "VTU00M", revision 0xf1, they read a Smart report.
b. The DWORD at Smart[324:328] represents a date (little-endian); if it is not 0x20120413, they don't patch the firmware. (Maybe only chips from 2012/04/13 are buggy?)
2. If the chip is buggy, whenever an MMC is attached or the device is resumed:
a. Issue CMD62(0xEFAC62EC) CMD62(0x10210000) to enter RAM write mode. Now you can write to RAM by issuing MMC_ERASE_GROUP_START(Address to write) MMC_ERASE_GROUP_END(Value to be written) MMC_ERASE(0).
b. *(0x40300) = 10 B5 03 4A 90 47 00 28 00 D1 FE E7 10 BD 00 00 73 9D 05 00
c. *(0x5C7EA) = E3 F7 89 FD
d. Exit RAM write mode by issuing CMD62(0xEFAC62EC) CMD62(0xDECCEE).
10 B5 looks like a common Thumb push (in ARM architecture). Disassembling the bytes that they write to 0x40300 yields the following code:
ROM:00040300                 PUSH    {R4,LR}
ROM:00040302                 LDR     R2, =0x59D73
ROM:00040304                 BLX     R2
ROM:00040306                 CMP     R0, #0
ROM:00040308                 BNE     locret_4030C
ROM:0004030A loc_4030A                               ; CODE XREF: ROM:loc_4030Aj
ROM:0004030A                 B       loc_4030A
ROM:0004030C ; ---------------------------------------------------------------------------
ROM:0004030C locret_4030C                            ; CODE XREF: ROM:00040308j
ROM:0004030C                 POP     {R4,PC}
ROM:0004030C ; ---------------------------------------------------------------------
Disassembling what they write to 0x5C7EA yields this:
ROM:0005C7EA                 BL      0x40300
Looks like it is indeed Thumb code.
If we could dump the eMMC RAM, we would understand what has been changed.

By inspecting some code, it seems that we know how to dump the eMMC RAM:
Look at the function mmc_set_wearlevel_page in line 206. It patches the RAM (using the method mentioned before), then it validates what it has written (in lines 255-290). Seems that the procedure to read the RAM is as following:
1. CMD62(0xEFAC62EC) CMD62(0x10210002) to enter RAM reading mode
2. MMC_ERASE_GROUP_START(Address to read) MMC_ERASE_GROUP_END(Length to read) MMC_ERASE(0)
3. MMC_READ_SINGLE_BLOCK to read the data
4. CMD62(0xEFAC62EC) CMD62(0xDECCEE) to exit RAM reading mode

I don't want to run this on my device, because I'm afraid - messing with the eMMC doesn't sound like a very good idea on my device (I don't have a spare one).
Does someone have a development device which he doesn't mind to risk, and want to dump the eMMC firmware from it?
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