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| author | Michael Brown <mcb30@ipxe.org> | 2025-02-13 14:18:15 +0000 |
|---|---|---|
| committer | Michael Brown <mcb30@ipxe.org> | 2025-02-13 15:25:35 +0000 |
| commit | 5056e8ad936742ba410031cff14c0f72d87805fc (patch) | |
| tree | 843fe48d0e4eeea4d78e4c30e31c16268def5ff3 /src/arch/arm32/include/bits/bigint.h | |
| parent | bd90abf487a6b0500f457193f86ff54fd2be3143 (diff) | |
| download | ipxe-5056e8ad936742ba410031cff14c0f72d87805fc.tar.gz | |
[crypto] Expose shifted out bit from big integer shifts
Expose the bit shifted out as a result of shifting a big integer left
or right.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Diffstat (limited to 'src/arch/arm32/include/bits/bigint.h')
| -rw-r--r-- | src/arch/arm32/include/bits/bigint.h | 22 |
1 files changed, 14 insertions, 8 deletions
diff --git a/src/arch/arm32/include/bits/bigint.h b/src/arch/arm32/include/bits/bigint.h index 95de32d83..988bef5ff 100644 --- a/src/arch/arm32/include/bits/bigint.h +++ b/src/arch/arm32/include/bits/bigint.h @@ -123,16 +123,18 @@ bigint_subtract_raw ( const uint32_t *subtrahend0, uint32_t *value0, * * @v value0 Element 0 of big integer * @v size Number of elements + * @ret out Bit shifted out */ -static inline __attribute__ (( always_inline )) void +static inline __attribute__ (( always_inline )) int bigint_shl_raw ( uint32_t *value0, unsigned int size ) { bigint_t ( size ) __attribute__ (( may_alias )) *value = ( ( void * ) value0 ); uint32_t *discard_value; uint32_t *discard_end; uint32_t discard_value_i; + int carry; - __asm__ __volatile__ ( "adds %1, %0, %5, lsl #2\n\t" /* clear CF */ + __asm__ __volatile__ ( "adds %1, %0, %1, lsl #2\n\t" /* clear CF */ "\n1:\n\t" "ldr %2, [%0]\n\t" "adcs %2, %2\n\t" @@ -142,9 +144,10 @@ bigint_shl_raw ( uint32_t *value0, unsigned int size ) { : "=l" ( discard_value ), "=l" ( discard_end ), "=l" ( discard_value_i ), + "=@cccs" ( carry ), "+m" ( *value ) - : "0" ( value0 ), "1" ( size ) - : "cc" ); + : "0" ( value0 ), "1" ( size ) ); + return carry; } /** @@ -152,16 +155,18 @@ bigint_shl_raw ( uint32_t *value0, unsigned int size ) { * * @v value0 Element 0 of big integer * @v size Number of elements + * @ret out Bit shifted out */ -static inline __attribute__ (( always_inline )) void +static inline __attribute__ (( always_inline )) int bigint_shr_raw ( uint32_t *value0, unsigned int size ) { bigint_t ( size ) __attribute__ (( may_alias )) *value = ( ( void * ) value0 ); uint32_t *discard_value; uint32_t *discard_end; uint32_t discard_value_i; + int carry; - __asm__ __volatile__ ( "adds %1, %0, %5, lsl #2\n\t" /* clear CF */ + __asm__ __volatile__ ( "adds %1, %0, %1, lsl #2\n\t" /* clear CF */ "\n1:\n\t" "ldmdb %1!, {%2}\n\t" "rrxs %2, %2\n\t" @@ -171,9 +176,10 @@ bigint_shr_raw ( uint32_t *value0, unsigned int size ) { : "=l" ( discard_value ), "=l" ( discard_end ), "=l" ( discard_value_i ), + "=@cccs" ( carry ), "+m" ( *value ) - : "0" ( value0 ), "1" ( size ) - : "cc" ); + : "0" ( value0 ), "1" ( size ) ); + return carry; } /** |