Assembly 理解ARM汇编代码
有人能给我解释一下这个简短的节目是做什么的吗Assembly 理解ARM汇编代码,assembly,arm,Assembly,Arm,有人能给我解释一下这个简短的节目是做什么的吗 ORIGIN 0x1000 one DEFW 13 two DEFW 29 three DEFW 0 ORIGIN 0x1010 ENTRY ADR R0, one LDR R1, [R0] LDR R2, [R0, #4] ADD R1, R2, R1 STR R1, [R0, #8] SWI 2 如果我的想法正确,它会将“一”添加到“二”,并将结果放在“三”中。我说的对吗?是的 ORIGIN 0x1000 # Start at
ORIGIN 0x1000
one DEFW 13
two DEFW 29
three DEFW 0
ORIGIN 0x1010
ENTRY
ADR R0, one
LDR R1, [R0]
LDR R2, [R0, #4]
ADD R1, R2, R1
STR R1, [R0, #8]
SWI 2
如果我的想法正确,它会将“一”添加到“二”,并将结果放在“三”中。我说的对吗?是的
ORIGIN 0x1000 # Start at address 0x1000
one DEFW 13 # Allocate 4-bytes of space for a variable called one and set it to 13
two DEFW 29 # Allocate 4-bytes of space for a variable called two and set it to 29
three DEFW 0 # Allocate 4-bytes of space for a variable called three and set it to 0
ORIGIN 0x1010 # Skip ahead to address 0x1010 (this really leaves a 4-byte gap)
ENTRY # Mark next instruction as the begining of program
ADR R0, one # Load address of one into R0
LDR R1, [R0] # Load contents of one (pointed to but R0) into R1
LDR R2, [R0, #4] # Load contents of two (pointed to but R0 + 4) into R2
ADD R1, R2, R1 # R1 = R2 + R1
STR R1, [R0, #8] # Store R1 into three (pointed to but R0 + 8)
SWI 2 # Execute a software interrupt
或
不确定“SWI 2”可能是特定于您的平台。可能只是一个通用的程序结束调用。+1:似乎表明
SWI 2
将打印到某种调试流(至少在该系统上)。在某些ARM系统上,SWI代表“软件中断”。SWI是软件中断指令。正如@Pete Fordham所说,什么是SWI 2取决于平台。这是家庭作业吗?你为什么把它弄糊涂了?如果你这样做,对别人没用。
three = one + two