ARM编程实例.
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第四章ARM程序设计基础 1 汇编语言程序示例
Example1/Example1.DOC
; 例一：数据块拷贝，利用LDR/STR指令
; 项目名：Example1.mcp，文件名：Example1.s ——————————————————————————————————
AREA Block, CODE, READONLY
num EQU 10
ENTRY
start
LDR R0, =src
LDR R1, =dst
MOV R2, #num
blockcopy
LDR R3, [R0], #4
STR R3, [R1], #4
SUBS R2, R2, #1
BNE blockcopy
B .
AREA BlockData, DATA, READWRITE
src DCD 0,1,2,3,4,5,6,7,8,9
dst SPACE 10*4
END
Example2/Example2.DOC
; 例二：数据块拷贝，利用LDM/STM指令
; 项目名：Example2.mcp，文件名：Example2.s ——————————————————————————————————
AREA Block, CODE, READONLY
num EQU 20
ENTRY
start
LDR R0, =src
第四章ARM程序设计基础 2
LDR R1, =dst
MOV R2, #num
MOV SP, #0x400
blockcopy
MOVS R3, R2, LSR #3
BEQ copywords
STMFD SP!, {R4-R11}
octcopy
LDMIA R0!, {R4-R11}
STMIA R1!, {R4-R11}
SUBS R3, R3, #1
BNE octcopy
LDMFD SP!, {R4-R11}
copywords
ANDS R2, R2, #7
BEQ stop
wordcopy
LDR R3, [R0], #4
STR R3, [R1], #4
SUBS R2, R2, #1
BNE wordcopy
stop
B .
AREA BlockData, DATA, READWRITE
src DCD 0,1,2,3,4,5,6,7,8,9,0,1,2,3,4,5,6,7,8,9
dst SPACE 20*4
END
Example3/Example3.DOC
；例三：ADR伪指令
；项目名：Example3.mcp，文件名：Example3.s ———————————————————————————————————————
第四章ARM程序设计基础 3
AREA adrlabel1, CODE, READONLY
ENTRY
start
BL func
B .
LTORG
func
ADR R0, start
ADR R1, DataArea
;ADR R2, DataArea+4300
ADRL R3, DataArea+4300
MOV PC, LR
DataArea
SPACE 8000
END
Example4/Example4.DOC
；例四：LDR伪指令
；项目名：Example4.mcp，文件名：Example4.s ———————————————————————————————————————AREA LDRlabel1, CODE, READONLY
ENTRY
start
BL func1
BL func2
B .
func1
LDR R0, =start
LDR R1, =Darea+12
LDR R2, =Darea+6000
MOV PC, LR
LTORG
第四章ARM程序设计基础 4
func2
LDR R3, =Darea+6000
LDR R4, =Darea+6004
MOV PC, LR
Darea
SPACE 8000
END
Example5/Example5.DOC
；例五：利用跳转表实现程序跳转
；项目名：Example5.mcp，文件名：Example5.s ———————————————————————————————————————
AREA Jump, CODE, READONLY
num EQU 2
ENTRY
start
MOV R0, #0
MOV R1, #3
MOV R2, #2
BL arithfunc
B .
arithfunc
CMP R0, #num
MOVHS PC, LR
ADR R3, JumpTable
LDR PC, [R3,R0,LSL #2]
JumpTable
DCD DoAdd
DCD DoSub
DoAdd
ADD R0, R1, R2