arm and patch phys offset
michael at walle.cc
Mon Dec 12 17:06:09 EST 2011
Am Montag 12 Dezember 2011, 22:38:07 schrieb Nicolas Pitre:
> > But the non-patched entries always points to correct v2p/p2v
> > calls and in every case there is the unpatched add/sub instruction.
> Then, might it be possible that the cache is not properly turned off
> prior entering the kernel?
i'll have a look at that
> What bootloader do you use?
U-Boot 2011.09 + patches for bsp support
> You could try instrumenting the patching code, although it is a bit
> tricky because of the non-standard register life rules in that file.
> But something like this should tell you if the expected amount of fixups
> were applied:
> diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S
> index 08c82fd844..7f43d1fe01 100644
> --- a/arch/arm/kernel/head.S
> +++ b/arch/arm/kernel/head.S
> @@ -530,14 +530,23 @@ __fixup_a_pv_table:
> bcc 1b
> bx lr
> + mov r0, #0
> b 2f
> 1: ldr ip, [r7, r3]
> bic ip, ip, #0x000000ff
> orr ip, ip, r6 @ mask in offset bits 31-24
> str ip, [r7, r3]
> + add r0, r0, #1
> 2: cmp r4, r5
> ldrcc r7, [r4], #4 @ use branch for delay slot
> bcc 1b
> + mov r6, r2
> + mov r7, r3
> + bl printhex8 @ display number of fixups done in r0
> + mov r2, r6
> + mov r3, r7
> mov pc, lr
Thanks, although the kernel hangs now after it printed the number, i can see
it patched the correct number of stubs.
I'll have a look at the bootloader now.
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