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| author | Ard Biesheuvel <ardb@kernel.org> | 2023-01-30 21:50:55 +0300 |
|---|---|---|
| committer | Ard Biesheuvel <ardb@kernel.org> | 2023-02-03 20:09:00 +0300 |
| commit | 1758817e7ea822b1a7d1b95f0c35dd80d120805b (patch) | |
| tree | 56c555177859af4b16bbe6d8f9fbecd1687fa6de /drivers/firmware | |
| parent | 234fa51db95f3236a049557db735606908747f38 (diff) | |
| download | linux-1758817e7ea822b1a7d1b95f0c35dd80d120805b.tar.xz | |
efi: Use standard format for printing the EFI revision
The UEFI spec section 4.2.1 describes the way the human readable EFI
revision should be constructed from the 32-bit revision field in the
system table:
The upper 16 bits of this field contain the major revision value,
and the lower 16 bits contain the minor revision value. The minor
revision values are binary coded decimals and are limited to the
range of 00..99.
When printed or displayed UEFI spec revision is referred as (Major
revision).(Minor revision upper decimal).(Minor revision lower
decimal) or (Major revision).(Minor revision upper decimal) in case
Minor revision lower decimal is set to 0.
Let's adhere to this when logging the EFI revision to the kernel log.
Note that the bit about binary coded decimals is bogus, and the minor
revision lower decimal is simply the minor revision modulo 10, given the
symbolic definitions provided by the spec itself:
#define EFI_2_40_SYSTEM_TABLE_REVISION ((2<<16) | (40))
#define EFI_2_31_SYSTEM_TABLE_REVISION ((2<<16) | (31))
#define EFI_2_30_SYSTEM_TABLE_REVISION ((2<<16) | (30))
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Diffstat (limited to 'drivers/firmware')
| -rw-r--r-- | drivers/firmware/efi/efi.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index 53fa4d14da65..4bb30434ee4a 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -796,6 +796,7 @@ void __init efi_systab_report_header(const efi_table_hdr_t *systab_hdr, char vendor[100] = "unknown"; const efi_char16_t *c16; size_t i; + u16 rev; c16 = map_fw_vendor(fw_vendor, sizeof(vendor) * sizeof(efi_char16_t)); if (c16) { @@ -806,10 +807,14 @@ void __init efi_systab_report_header(const efi_table_hdr_t *systab_hdr, unmap_fw_vendor(c16, sizeof(vendor) * sizeof(efi_char16_t)); } - pr_info("EFI v%u.%.02u by %s\n", - systab_hdr->revision >> 16, - systab_hdr->revision & 0xffff, - vendor); + rev = (u16)systab_hdr->revision; + pr_info("EFI v%u.%u", systab_hdr->revision >> 16, rev / 10); + + rev %= 10; + if (rev) + pr_cont(".%u", rev); + + pr_cont(" by %s\n", vendor); if (IS_ENABLED(CONFIG_X86_64) && systab_hdr->revision > EFI_1_10_SYSTEM_TABLE_REVISION && |