On Wed, Nov 25, 2009 at 08:46:51AM +1000, Adam Nielsen wrote:
> I'm trying to port the kernel to an NCD HMX X-Terminal (MIPS R4600), but
> the one thing I have to do before I can actually boot the image is attach
> a signature to it. I have the signature 'code' in assembly[1], but I'm
> not sure how to link it so that it ends up as the first bit of code in
> the ELF image (the very first instruction is a 'b' to jump over the
> actual signature text.)
>
> Without this the boot monitor will refuse to boot the kernel. Any
> suggestions as to how I might accomplish this?
Take a look at arch/mips/kernel/head.S. This file will be the first on
the final linker call's command line, that is head.S's .text section will
end at the lowest address.
In head.S there is this
#ifdef CONFIG_BOOT_RAW
/*
* Give us a fighting chance of running if execution beings at the
* kernel load address. This is needed because this platform does
* not have a ELF loader yet.
*/
FEXPORT(__kernel_entry)
j kernel_entry
#endif
ifdef. Add your own magic stuff there, something like
#ifdef CONFIG_NCD_HMX
b 1f
nop
nop
.word 0x20
.asciz "XncdHMX"
.word 0, 0, 0
#endif
> [1] http://www.linux-mips.org/wiki/HMX
The wiki page says something about a CRC but just poking a 0x20 into a
constant address is not exactly a CRC calculation. Not sure how this
really is meant.
Ralf
