[coreboot-gerrit] Change in coreboot[master]: emulation/qemu-i440fx,q35: avoid writing to ROM

[Julian Stecklina (Code Review)]

Attention is currently required from: Nico Huber, Julian Stecklina.
Hello build bot (Jenkins), Nico Huber, Paul Menzel, Arthur Heymans,

I'd like you to reexamine a change. Please visit

https://review.coreboot.org/c/coreboot/+/59474

to look at the new patch set (#2).

Change subject: emulation/qemu-i440fx,q35: avoid writing to ROM
......................................................................

emulation/qemu-i440fx,q35: avoid writing to ROM

libcbfs has a workaround to avoid writing to ROM areas:

/* Hacky way to not load programs over read only media. The stages
         * that would hit this path initialize themselves. */
        if ((ENV_BOOTBLOCK || ENV_SEPARATE_VERSTAGE) &&
            !CONFIG(NO_XIP_EARLY_STAGES) && CONFIG(BOOT_DEVICE_MEMORY_MAPPED)) {

This workaround is not triggered in QEMU, because
BOOT_DEVICE_MEMORY_MAPPED is only selected for SPI boot devices. This
results in confusing (to the VMM developer) writes to read-only
memory.

As far as I can tell, this issue is weird but harmless, because the
code does memcpy to ROM with source == destination. The concensus in
the mailing list thread [1] was that it's worthwhile to be fixed
regardless.

[1] https://mail.coreboot.org/hyperkitty/list/[e-mail]/message/KDI6...

Change-Id: I5cefbc31f917021236105f7dc969118d612ac399
Signed-off-by: Julian Stecklina 
---
M src/mainboard/emulation/qemu-i440fx/Kconfig
M src/mainboard/emulation/qemu-q35/Kconfig
2 files changed, 2 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/74/59474/2