mb/qemu-{i440fx,q35}: reduce default ROM size to 8 MiB

By default, QEMU bails when trying to use bigger images mounted with
'-drive if=pflash', which is required to make use of writable flash
introduced in CB:82555. This changes both default size in Kconfig as
well as FMAP layouts.

Since QEMU 5.0.0 it is possible to change the limit of firmware size
with `max-fw-size` machine configuration option, up to 16 MiB, as bigger
sizes would overlap with IO APIC memory range. Default is still 8 MiB,
so it makes sense to have identical default in coreboot.

Error thrown by QEMU when trying to use too big ROM:

qemu-system-x86_64: combined size of system firmware exceeds 8388608 bytes

Change-Id: If36cb754a8e75e23bce49ff568dd88e5db279bb8
Signed-off-by: Krystian Hebel <krystian.hebel@3mdeb.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/82639
Reviewed-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Maciej Pijanowski <maciej.pijanowski@3mdeb.com>
Reviewed-by: Maximilian Brune <maximilian.brune@9elements.com>

1 files changed, 19 insertions, 0 deletions

diff --git a/src/mainboard/emulation/qemu-i440fx/vboot-rwa-8M.fmd b/src/mainboard/emulation/qemu-i440fx/vboot-rwa-8M.fmd
new file mode 100644
index 0000000000..55a38b79a9
--- /dev/null
+++ b/src/mainboard/emulation/qemu-i440fx/vboot-rwa-8M.fmd
@@ -0,0 +1,19 @@
+FLASH@0xff800000 0x800000 {
+	SI_BIOS 0x800000 {
+		RW_SECTION_A 0x3c0000 {
+			VBLOCK_A 0x10000
+			FW_MAIN_A(CBFS)
+			RW_FWID_A 0x40
+		}
+		RW_VPD(PRESERVE) 0x1000
+
+		WP_RO {
+			FMAP 0x800
+			RO_FRID 0x40
+			RO_PADDING 0x7c0
+			RO_VPD(PRESERVE) 0x1000
+			GBB 0x1e000
+			COREBOOT(CBFS)
+		}
+	}
+}