对XSCALE 堆栈结构的探讨

实验环境：

IXP 2400 （XSCALE ），小字节模式

实验代码：

int william_test_muti(int var)

{

0x1c72c0 _william_test_muti: MOV r12,r13

0x1c72c4 +0x004: STMDB r13!,{r11,r12,r14,pc}

0x1c72c8 +0x008: SUB r11,r12,#4

0x1c72cc +0x00c: SUB r13,r13,#0xc

0x1c72d0 +0x010: STR r0,[r11,#-0x10]

int d = 0,z = 10;

0x1c72d4 +0x014: MOV r3,#0

0x1c72d8 +0x018: STR r3,[r11,#-0x14]

0x1c72dc +0x01c: MOV r3,#0xa

0x1c72e0 +0x020: STR r3,[r11,#-0x18]

d = var*z;

0x1c72e4 +0x024: LDR r3,[r11,#-0x10]

0x1c72e8 +0x028: LDR r2,[r11,#-0x18]

0x1c72ec +0x02c: MUL r3,r2,r3

0x1c72f0 +0x030: STR r3,[r11,#-0x14]

taskSuspend(0);

0x1c72f4 +0x034: MOV r0,#0

0x1c72f8 +0x038: BL _taskSuspend

return d;

0x1c72fc +0x03c: LDR r3,[r11,#-0x14]

0x1c7300 +0x040: MOV r0,r3

0x1c7304 +0x044: B _william_test_muti + 0x48

}

0x1c7308 +0x048: LDMDB r11,{r11,r13,pc}

int william_test_add(int a,int b)

{

0x1c730c _william_test_add: MOV r12,r13

0x1c7310 +0x004: STMDB r13!,{r11,r12,r14,pc}

0x1c7314 +0x008: SUB r11,r12,#4

0x1c7318 +0x00c: SUB r13,r13,#0x14

0x1c731c +0x010: STR r0,[r11,#-0x10]

0x1c7320 +0x014: STR r1,[r11,#-0x14]

int c = 0;

0x1c7324 +0x018: MOV r3,#0

0x1c7328 +0x01c: STR r3,[r11,#-0x18]

int d = 0x99;

0x1c732c +0x020: MOV r3,#0x99

0x1c7330 +0x024: STR r3,[r11,#-0x1c]

int result = 0;

0x1c7334 +0x028: MOV r3,#0

0x1c7338 +0x02c: STR r3,[r11,#-0x20]

c = a+b+d ;

0x1c733c +0x030: LDR r3,[r11,#-0x10]

0x1c7340 +0x034: LDR r2,[r11,#-0x14]

0x1c7344 +0x038: ADD r3,r3,r2

0x1c7348 +0x03c: LDR r2,[r11,#-0x1c]

0x1c734c +0x040: ADD r3,r3,r2

0x1c7350 +0x044: STR r3,[r11,#-0x18]

result = william_test_muti(c);

0x1c7354 +0x048: LDR r0,[r11,#-0x18]

0x1c7358 +0x04c: BL _william_test_muti

0x1c735c +0x050: MOV r3,r0

0x1c7360 +0x054: STR r3,[r11,#-0x20]

return c;

0x1c7364 +0x058: LDR r3,[r11,#-0x18]

0x1c7368 +0x05c: MOV r0,r3

0x1c736c +0x060: B _william_test_add + 0x64

}

0x1c7370 +0x064: LDMDB r11,{r11,r13,pc}

实验结果：

-> william_test_add 1,5

-> ti t1

NAME ENTRY TID PRI STATUS PC SP ERRNO DELAY

---------- ------------ -------- --- ---------- -------- -------- ------- -----

t1 2d8488 2f31298 4 SUSPEND 2a696c 2f311cc 0 0

stack: base 0x2f31298 end 0x2f2c298 size 20476 high 252 margin 20224

options: 0x1d

VX_SUPERVISOR_MODE VX_DEALLOC_STACK VX_FP_TASK VX_STDIO

r0 = 0 r1 = 0 r2 = 0 r3 = 0

r4 = 2f31298 r5 = 2f31298 r6 = 0 r7 = 0

r8 = 2f31448 r9 = 0 r10 = 0 r11/fp = 2f31200

r12/ip = 3e1508 r13/sp = 2f311cc r14/lr = 0 pc = 2a696c

cpsr = 13

value = 0 = 0x0

-> d 0x2f311cc-0x20

02f311a0: 3fb7 0000 * ?..*

02f311b0: eeee eeee 64c0 0314 1298 02f3 1200 02f3 *.....d..........*

02f311c0: 11cc 02f3 64c0 0314 e86c 0030 eeee eeee *.....d..l.0.....*

02f311d0: eeee eeee eeee eeee eeee eeee 0000 0000 *................*

02f311e0: 0000 0000 72fc 001c 000a 0000 0636 0000 *.....r......6...*

02f311f0: 009f 0000 1224 02f3 1204 02f3 735c 001c *....$.......\s..*

02f31200: 72cc 001c 0000 0000 0099 0000 009f 0000 *.r..............*

02f31210: 0005 0000 0001 0000 0000 0000 1228 02f3 *............(...*

02f31220: 8514 002d 7318 001c 0000 0000 0000 0000 *..-..s..........*

02f31230: 0000 0000 0000 0000 0000 0000 0000 0000 *................*

02f31240: 0000 0000 0000 0000 0000 0000 0000 0000 *................*

02f31250: 0000 0000 e92c 0030 0000 0000 0000 0000 *....,.0.........*

02f31260: 0000 0000 0000 0000 0000 0000 0000 0000 *................*

02f31270: 1448 02f3 0005 0000 0000 0000 0000 0000 *H...............*

02f31280: 0000 0000 0000 0000 0000 0000 0000 0000 *................*

02f31290: 0000 0000 0000 0000 0000 0000 0000 0000 *................*

02f312a0: 0004 0000 0000 0000 0000 0000 *................*

value = 21 = 0x15

结果分析：

-> d 0x2f311cc-0x20

02f311a0: 3fb7 0000 * ?..*

02f311b0: eeee eeee 64c0 0314 1298 02f3 1200 02f3 *.....d..........*

02f311c0: 11cc 02f3 64c0 0314 e86c 0030 eeee eeee *.....d..l.0.....*

02f311d0: eeee eeee eeee eeee eeee eeee 0000 0000 *................*

<传递参数>

02f311e0: 0000 0000 72fc 001c 000a 0000 0636 0000 *.....r......6...*

<r0内容> (执行语句)z d

02f311f0: 009f 0000 1224 02f3 1204 02f3 735c 001c *....$.......\s..*

<传递参数>R11 R12 <返回地址>

02f31200: 72cc 001c 0000 0000 0099 0000 009f 0000 *.r..............*

<当前PC> result d c

02f31210: 0005 0000 0001 0000 0000 0000 1228 02f3 *............(...*

参数b 参数a