[kexec exploryng][sbf checking] need help

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Guys, we with Quarx now exploryng kexec module.
As far i can see, we need /proc/atags node to exist in system to use it.
Maybe you can help me.
I need that you flash all sbf that we have...
And check if such node exists(/proc/atags)
If so - we can get working kexec and custom kernels for ever.
Please ,check it.
Thanks!

Is /proc/atags just a copy of the atags struct (which comes from the CDT)? It's probably possible to create a module (using symsearch if necessary) to add that if it is all we need... but I assume quarx is aware of that approach? Worst case we just copy the bits out and fake it. Did you look into that already? In the interim, you could build a fastboot kernel that has /proc/atags for kexec testing (I assume--unless the Motorola kernel source doesn't include /proc/atags support then it will take more work and I assume none of the released kernels would have it). Time to start the grep incantations.

Edit: In arch/arm/Kconfig I see:

config ATAGS_PROC
        bool "Export atags in procfs"
        depends on KEXEC
        default y
        help
          Should the atags used to boot the kernel be exported in an "atags"
          file in procfs. Useful with kexec.

Default y means either that Motorola explicitly disabled it, or that it's been disabled in the OMAP tree.

boot5.img have atags support.
Already get that info to http://fjfalcon.ru/atags

It does look like /proc/atags is just a memcpy of the struct that comes from the CDT.

I think the problem is the /proc/atags depends on KEXEC support in the kernel. So needing /proc/atags is the tip of the iceberg and the iceberg is "we need a kernel that supports KEXEC". I'm guessing there's no chance in hell that's there on any kernels. I wonder if there's a way to check whether atags.c was included by looking at only the kernel images rather than flashing them all. So, I'm guessing boot5.img has KEXEC support. Or do you have a kexec module that you're injecting? They've tried kexec on Milestone a long time ago, so there must be a way around missing kexec in the kernel.

Damn, for now i used kexec-arm -e /sdcard/kernel and get phone frozen.
I need uart..

http://fjfalcon.ru/kexec_load.ko

Originally Posted by fjfalcon

Guys, we with Quarx now exploryng kexec module.
As far i can see, we need /proc/atags node to exist in system to use it.
Maybe you can help me.
I need that you flash all sbf that we have...
And check if such node exists(/proc/atags)
If so - we can get working kexec and custom kernels for ever.
Please ,check it.
Thanks!

I check if I had /proc/atags in a nandroid backup (French stock sbf) with unyaffs but I doesn't have.

Originally Posted by Zachary57

I check if I had /proc/atags in a nandroid backup (French stock sbf) with unyaffs but I doesn't have.

/proc is a memory filesystem generated by the kernel after boot, unfortunately. You would have to boot the kernel to check. Nevertheless I'm pretty confident that none of our kernels has it because enabling /proc/atags in the kernel *requires* also enabling kexec in the kernel according to the XT720's kernel source. I can't think of any reason for Motorola to ever enable kexec in their kernel (kexec allows booting a second kernel from the current kernel which is why we're interested in it--motorola developers would be using engineering devices and flash whatever kernel they want directly).

Originally Posted by fjfalcon

Guys, we with Quarx now exploryng kexec module.
As far i can see, we need /proc/atags node to exist in system to use it.
Maybe you can help me.
I need that you flash all sbf that we have...
And check if such node exists(/proc/atags)
If so - we can get working kexec and custom kernels for ever.
Please ,check it.
Thanks!

sir, there is no /proc/atags in modsbf .sbf . tqvm