From 8a48c923385ac86fe80ada3fa6555985494fd107 Mon Sep 17 00:00:00 2001 From: Patrick Rudolph Date: Wed, 12 Jun 2019 16:22:11 +0200 Subject: [PATCH] mb/emulation/qemu-riscv: Protect CBFS from payload loader The virt machine is special as it doesn't emulate flash and it puts the coreboot.rom at start of DRAM. The payload loader doesn't know about CBFS in DRAM and overwrites the CBFS while decompressing payloads, resulting in undefined behaviour. Mark the region as SRAM to make sure the payload won't overwrite the CBFS while decompressing. As payload is always decompressed to DRAM, it wouldn't touch SRAM memory regions. Change-Id: I36a18cb727f660ac9e77df413026627ea160c1e1 Signed-off-by: Patrick Rudolph Reviewed-on: https://review.coreboot.org/c/coreboot/+/33426 Tested-by: build bot (Jenkins) Reviewed-by: Philipp Deppenwiese --- src/mainboard/emulation/qemu-riscv/memlayout.ld | 17 ++++++++++++----- src/mainboard/emulation/qemu-riscv/rom_media.c | 2 +- 2 files changed, 13 insertions(+), 6 deletions(-) diff --git a/src/mainboard/emulation/qemu-riscv/memlayout.ld b/src/mainboard/emulation/qemu-riscv/memlayout.ld index 7f8ec3dd6a..2166d23f31 100644 --- a/src/mainboard/emulation/qemu-riscv/memlayout.ld +++ b/src/mainboard/emulation/qemu-riscv/memlayout.ld @@ -17,16 +17,23 @@ #include #include -//Stages start after CBFS in DRAM +// Stages start after CBFS in DRAM #define STAGES_START (QEMU_VIRT_DRAM + CONFIG_ROM_SIZE) SECTIONS { - DRAM_START(QEMU_VIRT_DRAM) + // the virt target doesn't emulate flash and just puts the CBFS into DRAM. + // fake SRAM where CBFS resides. It's only done for better integration. + SRAM_START(QEMU_VIRT_DRAM) BOOTBLOCK(QEMU_VIRT_DRAM, 64K) // CBFS goes here - STACK(STAGES_START, 4K) - ROMSTAGE(STAGES_START + 64K, 128K) - PRERAM_CBMEM_CONSOLE(STAGES_START + 192K, 8K) + SRAM_END(STAGES_START) + DRAM_START(STAGES_START) + +#if ENV_ROMSTAGE + ROMSTAGE(STAGES_START, 128K) +#endif + PRERAM_CBMEM_CONSOLE(STAGES_START + 128K, 8K) RAMSTAGE(STAGES_START + 200K, 16M) + STACK(STAGES_START + 200K + 16M, 4K) } diff --git a/src/mainboard/emulation/qemu-riscv/rom_media.c b/src/mainboard/emulation/qemu-riscv/rom_media.c index bac19846c5..79e5ca8f54 100644 --- a/src/mainboard/emulation/qemu-riscv/rom_media.c +++ b/src/mainboard/emulation/qemu-riscv/rom_media.c @@ -19,7 +19,7 @@ /* This assumes that the CBFS resides at start of dram, which is true for the * default configuration. */ static const struct mem_region_device boot_dev = - MEM_REGION_DEV_RO_INIT(_dram, CONFIG_ROM_SIZE); + MEM_REGION_DEV_RO_INIT(_sram, CONFIG_ROM_SIZE); const struct region_device *boot_device_ro(void) {