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cbfstool: Read XIP stage alignment requirements from ELF

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On x86_64 romstage can contain page tables and a page table pointer
which have an larger alignment requirement of 4096. Instead of
hardcoding it, read if from the ELF phdrs.

Change-Id: I94e4a4209b7441ecb2966a1342c3d46625771bb8
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/82102
Reviewed-by: Shuo Liu <shuo.liu@intel.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Jérémy Compostella <jeremy.compostella@intel.com>
Reviewed-by: Julius Werner <jwerner@chromium.org>
This commit is contained in:
Arthur Heymans 2024-04-29 10:04:59 +02:00 committed by Julius Werner
parent 71c9010443
commit 6ed0ba1e93
4 changed files with 20 additions and 23 deletions
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9
Makefile.mk
View File

@ -1276,15 +1276,6 @@ ifeq ($(CONFIG_ARCH_ROMSTAGE_ARM),y)
$(CONFIG_CBFS_PREFIX)/romstage-options := -b 0
endif
ifeq ($(CONFIG_ARCH_ROMSTAGE_X86_32)$(CONFIG_ARCH_ROMSTAGE_X86_64),y)
# Use a 64 byte alignment to provide a minimum alignment
# requirement for the overall romstage. While the first object within
# romstage could have a 4 byte minimum alignment that doesn't mean the linker
# won't decide the entire section should be aligned to a larger value. In the
# future cbfstool should add XIP files proper and honor the alignment
# requirements of the program segment.
#
# Make sure that segment for .car.data is ignored while adding romstage.
$(CONFIG_CBFS_PREFIX)/romstage-align := 64
ifeq ($(CONFIG_NO_XIP_EARLY_STAGES),y)
$(CONFIG_CBFS_PREFIX)/romstage-options := -S ".car.data"
else

23
util/cbfstool/cbfstool.c
View File

@ -1156,23 +1156,26 @@ static int cbfstool_convert_mkstage(struct buffer *buffer, uint32_t *offset,
struct cbfs_file *header)
{
struct buffer output;
size_t data_size;
int ret;
if (elf_program_file_size(buffer, &data_size) < 0) {
ERROR("Could not obtain ELF size\n");
return 1;
}
/*
* We need a final location for XIP parsing, so we need to call do_cbfs_locate() early
* here. That is okay because XIP stages may not be compressed, so their size cannot
* change anymore at a later point.
*/
if (param.stage_xip &&
do_cbfs_locate(offset, data_size)) {
ERROR("Could not find location for stage.\n");
return 1;
if (param.stage_xip) {
size_t data_size, alignment;
if (elf_program_file_size_align(buffer, &data_size, &alignment) < 0) {
ERROR("Could not obtain ELF size & alignment\n");
return 1;
}
param.alignment = MAX(alignment, param.alignment);
if (do_cbfs_locate(offset, data_size)) {
ERROR("Could not find location for stage.\n");
return 1;
}
}
struct cbfs_file_attr_stageheader *stageheader = (void *)

5
util/cbfstool/elfheaders.c
View File

@ -1434,12 +1434,13 @@ int elf_writer_add_rel(struct elf_writer *ew, const char *sym, Elf64_Addr addr)
return add_rel(rel_sec, &rel);
}
int elf_program_file_size(const struct buffer *input, size_t *file_size)
int elf_program_file_size_align(const struct buffer *input, size_t *file_size, size_t *align)
{
Elf64_Ehdr ehdr;
Elf64_Phdr *phdr;
int i;
size_t loadable_file_size = 0;
size_t align_size = 0;
if (elf_headers(input, &ehdr, &phdr, NULL))
return -1;
@ -1448,9 +1449,11 @@ int elf_program_file_size(const struct buffer *input, size_t *file_size)
if (phdr[i].p_type != PT_LOAD)
continue;
loadable_file_size += phdr[i].p_filesz;
align_size = MAX(align_size, phdr[i].p_align);
}
*file_size = loadable_file_size;
*align = align_size;
free(phdr);

6
util/cbfstool/elfparsing.h
View File

@ -114,9 +114,9 @@ int elf_writer_add_rel(struct elf_writer *ew, const char *sym, Elf64_Addr addr);
int elf_writer_serialize(struct elf_writer *ew, struct buffer *out);
/*
* Calculate the loadable program's file size footprint. Returns < 0 on error,
* 0 on success.
* Calculate the loadable program's file size footprint and alignment requirements.
* Returns < 0 on error, 0 on success.
*/
int elf_program_file_size(const struct buffer *input, size_t *file_size);
int elf_program_file_size_align(const struct buffer *input, size_t *file_size, size_t *align);
#endif /* ELFPARSING_H */