erebion/coreboot
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

util/smmstoretool: Support other block sizes

Browse source 
smmstoretool is effectively a UEFI variable store writing tool, with
a specific emphasis on the SMMSTORE backend implementation.

However, it could also support other backends. Since it's typical for
the variable store to be `n / 2 - 1` blocks, but not typical how large
each block should be, allow this to be overridden on the command line.

This is necessary because in EDK2, the module producing the firmware
volume block protocol, the backend, will initialise a HOB or set PCDs to
indicate the size of the store to the rest of the stack, and an
assertion will be hit if the store has been preseeded by smmstoretool
using differently-sized blocks.

For example, `make CFLAGS=-DSMM_BLOCK_SIZE=8192` builds this for a
firmware volume block protocol implementation with 8K blocks.

Change-Id: I08b78cfb0b591641f09fcf86f40dd31e6b6c9b30
Signed-off-by: Benjamin Doron <benjamin.doron@9elements.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/88427
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Alicja Michalska <ahplka19@gmail.com>
This commit is contained in:
Benjamin Doron 2025-07-11 15:20:00 -04:00 • committed by Matt DeVillier
commit 00d954977c
1 changed files with 8 additions and 4 deletions
Download patch file Download diff file Expand all files Collapse all files

12
util/smmstoretool/fv.c
View file

@ -11,7 +11,9 @@
#include "udk2017.h"
// The same as in `smmstore.h` header, which isn't in `commonlib`.
#ifndef SMM_BLOCK_SIZE
#define SMM_BLOCK_SIZE (64 * 1024)
#endif
static const EFI_GUID EfiVariableGuid = EFI_VARIABLE_GUID;
@ -37,10 +39,12 @@ bool fv_init(struct mem_range_t fv)
{
if (fv.length % SMM_BLOCK_SIZE != 0) {
fprintf(stderr,
"Firmware Volume size is not a multiple of 64KiB\n");
"Firmware Volume size is not a multiple of the block size (%dKiB)\n",
SMM_BLOCK_SIZE / 1024);
return false;
}
uint32_t number_of_blocks = fv.length / SMM_BLOCK_SIZE;
memset(fv.start, 0xff, fv.length);
const EFI_FIRMWARE_VOLUME_HEADER vol_hdr = {
@ -58,7 +62,7 @@ bool fv_init(struct mem_range_t fv)
+ sizeof(EFI_FV_BLOCK_MAP_ENTRY),
.Revision = EFI_FVH_REVISION,
.BlockMap[0] = {
.NumBlocks = fv.length / SMM_BLOCK_SIZE,
.NumBlocks = number_of_blocks,
.Length = SMM_BLOCK_SIZE,
},
};
@ -74,9 +78,9 @@ bool fv_init(struct mem_range_t fv)
const VARIABLE_STORE_HEADER var_store_hdr = {
.Signature = EfiAuthenticatedVariableGuid,
// Actual size of the storage is block size, the rest is
// Actual size of the storage is `n / 2 - 1` blocks, the rest is
// Fault Tolerant Write (FTW) space and the FTW spare space.
.Size = SMM_BLOCK_SIZE - vol_hdr.HeaderLength,
.Size = ((number_of_blocks / 2 - 1) * SMM_BLOCK_SIZE) - vol_hdr.HeaderLength,
.Format = VARIABLE_STORE_FORMATTED,
.State = VARIABLE_STORE_HEALTHY,
};