On 15.02.18 07:40, Andre Heider wrote:
The value at the end of the rom is not a pointer, it is an offset relative to the end of rom.
Do you have any documentation pointers to this? Even just pointing to a specific line of code in coreboot would be helpful in case anyone wants to read it up.
Signed-off-by: Andre Heider a.heider@gmail.com
fs/cbfs/cbfs.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/fs/cbfs/cbfs.c b/fs/cbfs/cbfs.c index 6e1107d751..46da8f134f 100644 --- a/fs/cbfs/cbfs.c +++ b/fs/cbfs/cbfs.c @@ -168,9 +168,9 @@ static int file_cbfs_load_header(uintptr_t end_of_rom, struct cbfs_header *header) { struct cbfs_header *header_in_rom;
- int32_t offset = *(u32 *)(end_of_rom - 3);
Accessing a pointer that gets subtracted by 3 looks terribly wrong. Unfortunately it's correct, because the pointer itself is unaligned.
How about we change the logic so that we calculate an aligned pointer (after_rom?) which we sanity check for alignment and base all calculations on that instead?
That way the next time someone comes around he's not getting puzzled why we're subtracting 3 and adding 1 to the pointer ;).
Alex
- header_in_rom = (struct cbfs_header *)(uintptr_t)
*(u32 *)(end_of_rom - 3);
header_in_rom = (struct cbfs_header *)(end_of_rom + offset + 1); swap_header(header, header_in_rom);
if (header->magic != good_magic || header->offset >