自己写的几个ARM汇编内存操作函数

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自己写的几个ARM汇编内存操作函数

@=====================Subroutine====================
@ sysMemSet, Memory set in byte transfer (1 byte)
@             R0:    Destination Address
@            R1:    value
@             R2:    Length in Bytes
@===================================================
.type         sysMemSet, %function
.global        sysMemSet
sysMemSet:
        CMP     R2, #0x00
        BEQ     .MemSetEnd

.MemSetLoop:
        STRB    R1,    [R0], #+1
        SUBS    R2, R2, #1
        BNE     .MemSetLoop

.MemSetEnd:

        MOV        PC,    LR

@=====================Subroutine====================
@ sysMemSetHW, Memory set in half word (2 bytes)
@             R0:    Destination Address
@            R1:    value
@             R2:    Length in half words
@===================================================
.type         sysMemSetHW, %function
.global        sysMemSetHW
sysMemSetHW:
        CMP     R2, #0x00
        BEQ     .MemSetHWEnd

.MemSetHWLoop:
        STRH    R1,    [R0], #+2
        SUBS    R2, R2, #1
        BNE     .MemSetHWLoop

.MemSetHWEnd:

        MOV        PC,    LR

@=====================Subroutine====================
@ sysMemSetW, Memory set in word (4 bytes)
@             R0:    Destination Address
@            R1:    value
@             R2:    Length in words
@===================================================
.type         sysMemSetW, %function
.global        sysMemSetW
sysMemSetW:
        CMP     R2, #0x00
        BEQ     .MemSetWEnd

.MemSetWLoop:
        STR    R1,    [R0], #+4
        SUBS    R2, R2, #1
        BNE     .MemSetWLoop

.MemSetWEnd:

        MOV        PC,    LR

@=====================Subroutine====================
@ sysMemCopy, Copy Memory data in byte transfer
@             R0:    Destination Address
@             R1:    Source Address
@             R2:    Length in Bytes
@===================================================
.type         sysMemCopy, %function
.global        sysMemCopy
sysMemCopy:
        CMP     R2, #0x00
        BEQ     .MemCopyEnd

.MemCopyLoop:
        LDRB    R3, [R1], #+1
        STRB    R3, [R0], #+1
        SUBS    R2, R2, #1
        BNE     .MemCopyLoop

.MemCopyEnd:

        MOV        PC,    LR

@=====================Subroutine====================
@ sysMemCopyHW, Copy Memory data in byte transfer
@             R0:    Destination Address
@             R1:    Source Address
@             R2:    Length in half words
@===================================================
.type         sysMemCopyHW, %function
.global        sysMemCopyHW
sysMemCopyHW:
        CMP     R2, #0x00
        BEQ     .MemCopyHWEnd

.MemCopyHWLoop:
        LDRH    R3, [R1], #+2
        STRH    R3, [R0], #+2
        SUBS    R2, R2, #1
        BNE     .MemCopyHWLoop

.MemCopyHWEnd:

        MOV        PC,    LR

@=====================Subroutine====================
@ sysMemCopyW, Copy Memory data in byte transfer
@             R0:    Destination Address
@             R1:    Source Address
@             R2:    Length in words
@===================================================
.type         sysMemCopyW, %function
.global        sysMemCopyW
sysMemCopyW:
        CMP     R2, #0x00
        BEQ     .MemCopyWEnd

.MemCopyWLoop:
        LDR       R3, [R1], #+4
        STR       R3, [R0], #+4
        SUBS    R2, R2, #1
        BNE      .MemCopyWLoop

.MemCopyWEnd:

        MOV        PC,    LR

@=====================Subroutine====================
@ sysMemCopyRev, Copy Memory data in byte transfer
@             R0:    Destination Address
@             R1:    Source Address
@             R2:    Length in Bytes
@===================================================
.type         sysMemCopyRev, %function
.global        sysMemCopyRev
sysMemCopyRev:
        CMP     R2, #0x00
        BEQ     .RamCopyRevEnd

.RamCopyRevLoop:
        LDRB    R3, [R1], #-1
        STRB    R3, [R0], #-1
        SUBS    R2, R2, #1
        BNE     .RamCopyRevLoop

.RamCopyRevEnd:

        MOV        PC,    LR