From ddd4f9a7179ccc0772f1a26cdb70d68c19ae9140 Mon Sep 17 00:00:00 2001 From: Duncan Laurie Date: Tue, 17 Mar 2020 18:46:28 -0700 Subject: mb/emulation/qemu-i440fx: Reserve low memory Ensure that the low memory is properly reserved so it does not get marked as normal RAM and get wiped or reused by firmware or the kernel. This ensures that the low RSDP is always available for the kernel. This is only noticed if something wipes the RSDP before the kernel boots, which happens if you use the depthcharge payload and boot in developer mode. Change-Id: I7295018416229bc957ecbf26f77623a57965557e Signed-off-by: Duncan Laurie Reviewed-on: https://review.coreboot.org/c/coreboot/+/39834 Tested-by: build bot (Jenkins) Reviewed-by: Patrick Rudolph Reviewed-by: Paul Menzel --- src/mainboard/emulation/qemu-i440fx/northbridge.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'src') diff --git a/src/mainboard/emulation/qemu-i440fx/northbridge.c b/src/mainboard/emulation/qemu-i440fx/northbridge.c index b30723dd74..355f13cd36 100644 --- a/src/mainboard/emulation/qemu-i440fx/northbridge.c +++ b/src/mainboard/emulation/qemu-i440fx/northbridge.c @@ -129,6 +129,12 @@ static void cpu_pci_domain_read_resources(struct device *dev) "debugcon"); } + /* A segment is legacy VGA region */ + mmio_resource(dev, idx++, 0xa0000 / KiB, (0xc0000 - 0xa0000) / KiB); + + /* C segment to 1MB is reserved RAM (low tables) */ + reserved_ram_resource(dev, idx++, 0xc0000 / KiB, (1 * MiB - 0xc0000) / KiB); + if (q35 && ((tomk * 1024) < 0xb0000000)) { /* * Reserve the region between top-of-ram and the -- cgit v1.2.3