hackedteam/vector-edk

    CODE32

    EXPORT    |CrcUpdateT4@16|

    AREA    |.text|, CODE, ARM

    MACRO
    CRC32_STEP_1

    ldrb    r4, [r1], #1
    subs    r2, r2, #1
    eor     r4, r4, r0
    and     r4, r4, #0xFF
    ldr     r4, [r3, +r4, lsl #2]
    eor     r0, r4, r0, lsr #8

    MEND


    MACRO
    CRC32_STEP_4 $STREAM_WORD
    
    eor     r7, r7, r8
    eor     r7, r7, r9
    eor     r0, r0, r7
    eor     r0, r0, $STREAM_WORD
    ldr     $STREAM_WORD, [r1], #4
    
    and     r7, r0, #0xFF
    and     r8, r0, #0xFF00
    and     r9, r0, #0xFF0000
    and     r0, r0, #0xFF000000

    ldr     r7, [r6, +r7, lsl #2]
    ldr     r8, [r5, +r8, lsr #6]
    ldr     r9, [r4, +r9, lsr #14]
    ldr     r0, [r3, +r0, lsr #22]
    
    MEND


|CrcUpdateT4@16| PROC

    stmdb   sp!, {r4-r11, lr}
    cmp     r2, #0
    beq     |$fin|

|$v1|
    tst     r1, #7
    beq     |$v2|
    CRC32_STEP_1
    bne     |$v1|

|$v2|
    cmp     r2, #16
    blo     |$v3|

    ldr     r10, [r1], #4
    ldr     r11, [r1], #4

    add     r4, r3, #0x400 
    add     r5, r3, #0x800
    add     r6, r3, #0xC00

    mov     r7, #0
    mov     r8, #0
    mov     r9, #0

    sub     r2, r2, #16

|$loop|
    ; pld     [r1, #0x40]

    CRC32_STEP_4 r10
    CRC32_STEP_4 r11

    subs    r2, r2, #8
    bhs     |$loop|

    sub     r1, r1, #8
    add     r2, r2, #16

    eor     r7, r7, r8
    eor     r7, r7, r9
    eor     r0, r0, r7

|$v3|
    cmp     r2, #0
    beq     |$fin|

|$v4|
    CRC32_STEP_1
    bne     |$v4|

|$fin|
    ldmia   sp!, {r4-r11, pc}

|CrcUpdateT4@16| ENDP

    END