qemu-armv7: memcpy to ROMSTAGE_BASE

[Piotr Król]

Hi all,
during debugging of qemu-armv7 I found that coreboot performs memcpy to
ROMSTAGE_BASE area. This is in src/arch/armv7/memcpy.S:

3:      PLD(    pld     [r1, #124]              )
4:              ldr8w   r1, r3, r4, r5, r6, r7, r8, ip, lr, abort=20f
                subs    r2, r2, #32
                str8w   r0, r3, r4, r5, r6, r7, r8, ip, lr, abort=20f
                bge     3b

r0 at this moment (for qemu-armv7) is 0x10000 (ROMSTAGE_BASE). Is it ok that
ROM area is used as storage during memory copying ? Shouldn't it be considered
read only ? Am I missing something here ?

Because coreboot execute from RAM this is not the problem but when I try to
execute it from flash ('-bios' option) I'm unable to boot because qemu emulates
flash as read only area.

Is it ok to move ROMSTAGE_BASE to SRAM or this is violation of general rule ?

Thanks,
Piotr

[ron minnich]

The ROMSTAGE on ARM is expected to be SRAM. When you know the SRAM
address for a given mainboard, you need to set it up in Kconfig for
*just* that mainboard.

Nice work, I think you're getting close!

ron