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| author | Ard Biesheuvel <ard.biesheuvel@linaro.org> | 2015-03-27 17:27:14 +0000 |
|---|---|---|
| committer | lersek <lersek@Edk2> | 2015-03-27 17:27:14 +0000 |
| commit | 55f5af1871d07d62def7bafa20b4761cc8b66e7d (patch) | |
| tree | ddc8668bc2eec00ce9bad8c1da1145ccc6148ff3 | |
| parent | e2ab3f819f4e8165c24bd6f4fdc24ef17bdf458b (diff) | |
| download | edk2-platforms-55f5af1871d07d62def7bafa20b4761cc8b66e7d.tar.xz | |
MdePkg: fix ARM version of InternalMathSwapBytes64 ()
The ARM asm implementation of InternalMathSwapBytes64 () does
interesting things if bit 7 of operand r1 (upper 32 bits of the
input value) is set. After the recursive swap, bit 7 ends up in
the sign bit position, after which it is right shifted with sign
extension, and or'ed with the upper half of the output value.
This means SwapBytes64 (0x00000080_00000000) returns an incorrect
value of 0xFFFFFFFF_80000000.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Ronald Cron <Ronald.Cron@arm.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@17077 6f19259b-4bc3-4df7-8a09-765794883524
| -rwxr-xr-x | MdePkg/Library/BaseLib/Arm/Math64.S | 16 |
1 files changed, 4 insertions, 12 deletions
diff --git a/MdePkg/Library/BaseLib/Arm/Math64.S b/MdePkg/Library/BaseLib/Arm/Math64.S index 4d97573920..e2512621fe 100755 --- a/MdePkg/Library/BaseLib/Arm/Math64.S +++ b/MdePkg/Library/BaseLib/Arm/Math64.S @@ -256,22 +256,14 @@ L30: GCC_ASM_EXPORT(InternalMathSwapBytes64)
ASM_PFX(InternalMathSwapBytes64):
- @ args = 0, pretend = 0, frame = 0
- @ frame_needed = 1, uses_anonymous_args = 0
- stmfd sp!, {r4, r5, r6, r7, lr}
- add r7, sp, #12
+ stmfd sp!, {r4, r5, r7, lr}
mov r5, r1
bl ASM_PFX(SwapBytes32)
- mov r6, r0
+ mov r4, r0
mov r0, r5
bl ASM_PFX(SwapBytes32)
- mov r4, r6
- mov r5, r4, asr #31
- mov r2, #0
- mov r1, r0, asr #31
- orr r0, r0, r2
- orr r1, r1, r4
- ldmfd sp!, {r4, r5, r6, r7, pc}
+ mov r1, r4
+ ldmfd sp!, {r4, r5, r7, pc}
ASM_FUNCTION_REMOVE_IF_UNREFERENCED
\ No newline at end of file |