Files
xv6-custom-os/cat.asm

1269 lines
44 KiB
NASM

_cat: file format elf32-i386
Disassembly of section .text:
00000000 <main>:
printf(1, "cat: read error\n");
exit();
}
}
int main(int argc, char *argv[]) {
0: 8d 4c 24 04 lea 0x4(%esp),%ecx
4: 83 e4 f0 and $0xfffffff0,%esp
7: ff 71 fc push -0x4(%ecx)
a: 55 push %ebp
b: 89 e5 mov %esp,%ebp
d: 57 push %edi
e: 56 push %esi
f: be 01 00 00 00 mov $0x1,%esi
14: 53 push %ebx
15: 51 push %ecx
16: 83 ec 18 sub $0x18,%esp
19: 8b 01 mov (%ecx),%eax
1b: 8b 59 04 mov 0x4(%ecx),%ebx
1e: 89 45 e4 mov %eax,-0x1c(%ebp)
21: 83 c3 04 add $0x4,%ebx
int fd, i;
if (argc <= 1) {
24: 83 f8 01 cmp $0x1,%eax
27: 7e 54 jle 7d <main+0x7d>
29: 8d b4 26 00 00 00 00 lea 0x0(%esi,%eiz,1),%esi
cat(0);
exit();
}
for (i = 1; i < argc; i++) {
if ((fd = open(argv[i], 0)) < 0) {
30: 83 ec 08 sub $0x8,%esp
33: 6a 00 push $0x0
35: ff 33 push (%ebx)
37: e8 8f 03 00 00 call 3cb <open>
3c: 83 c4 10 add $0x10,%esp
3f: 89 c7 mov %eax,%edi
41: 85 c0 test %eax,%eax
43: 78 24 js 69 <main+0x69>
printf(1, "cat: cannot open %s\n", argv[i]);
exit();
}
cat(fd);
45: 83 ec 0c sub $0xc,%esp
for (i = 1; i < argc; i++) {
48: 83 c6 01 add $0x1,%esi
4b: 83 c3 04 add $0x4,%ebx
cat(fd);
4e: 50 push %eax
4f: e8 3c 00 00 00 call 90 <cat>
close(fd);
54: 89 3c 24 mov %edi,(%esp)
57: e8 9f 03 00 00 call 3fb <close>
for (i = 1; i < argc; i++) {
5c: 83 c4 10 add $0x10,%esp
5f: 39 75 e4 cmp %esi,-0x1c(%ebp)
62: 75 cc jne 30 <main+0x30>
}
exit();
64: e8 fa 02 00 00 call 363 <exit>
printf(1, "cat: cannot open %s\n", argv[i]);
69: 50 push %eax
6a: ff 33 push (%ebx)
6c: 68 2b 08 00 00 push $0x82b
71: 6a 01 push $0x1
73: e8 68 04 00 00 call 4e0 <printf>
exit();
78: e8 e6 02 00 00 call 363 <exit>
cat(0);
7d: 83 ec 0c sub $0xc,%esp
80: 6a 00 push $0x0
82: e8 09 00 00 00 call 90 <cat>
exit();
87: e8 d7 02 00 00 call 363 <exit>
8c: 66 90 xchg %ax,%ax
8e: 66 90 xchg %ax,%ax
00000090 <cat>:
void cat(int fd) {
90: 55 push %ebp
91: 89 e5 mov %esp,%ebp
93: 56 push %esi
94: 8b 75 08 mov 0x8(%ebp),%esi
97: 53 push %ebx
while ((n = read(fd, buf, sizeof(buf))) > 0) {
98: eb 1d jmp b7 <cat+0x27>
9a: 8d b6 00 00 00 00 lea 0x0(%esi),%esi
if (write(1, buf, n) != n) {
a0: 83 ec 04 sub $0x4,%esp
a3: 53 push %ebx
a4: 68 a0 0b 00 00 push $0xba0
a9: 6a 01 push $0x1
ab: e8 23 03 00 00 call 3d3 <write>
b0: 83 c4 10 add $0x10,%esp
b3: 39 d8 cmp %ebx,%eax
b5: 75 25 jne dc <cat+0x4c>
while ((n = read(fd, buf, sizeof(buf))) > 0) {
b7: 83 ec 04 sub $0x4,%esp
ba: 68 00 02 00 00 push $0x200
bf: 68 a0 0b 00 00 push $0xba0
c4: 56 push %esi
c5: e8 b1 02 00 00 call 37b <read>
ca: 83 c4 10 add $0x10,%esp
cd: 89 c3 mov %eax,%ebx
cf: 85 c0 test %eax,%eax
d1: 7f cd jg a0 <cat+0x10>
if (n < 0) {
d3: 75 1b jne f0 <cat+0x60>
}
d5: 8d 65 f8 lea -0x8(%ebp),%esp
d8: 5b pop %ebx
d9: 5e pop %esi
da: 5d pop %ebp
db: c3 ret
printf(1, "cat: write error\n");
dc: 83 ec 08 sub $0x8,%esp
df: 68 08 08 00 00 push $0x808
e4: 6a 01 push $0x1
e6: e8 f5 03 00 00 call 4e0 <printf>
exit();
eb: e8 73 02 00 00 call 363 <exit>
printf(1, "cat: read error\n");
f0: 50 push %eax
f1: 50 push %eax
f2: 68 1a 08 00 00 push $0x81a
f7: 6a 01 push $0x1
f9: e8 e2 03 00 00 call 4e0 <printf>
exit();
fe: e8 60 02 00 00 call 363 <exit>
103: 66 90 xchg %ax,%ax
105: 66 90 xchg %ax,%ax
107: 66 90 xchg %ax,%ax
109: 66 90 xchg %ax,%ax
10b: 66 90 xchg %ax,%ax
10d: 66 90 xchg %ax,%ax
10f: 90 nop
00000110 <strcpy>:
#include "stat.h"
#include "fcntl.h"
#include "user.h"
#include "x86.h"
char*strcpy(char *s, const char *t) {
110: 55 push %ebp
char *os;
os = s;
while ((*s++ = *t++) != 0) {
111: 31 c0 xor %eax,%eax
char*strcpy(char *s, const char *t) {
113: 89 e5 mov %esp,%ebp
115: 53 push %ebx
116: 8b 4d 08 mov 0x8(%ebp),%ecx
119: 8b 5d 0c mov 0xc(%ebp),%ebx
11c: 8d 74 26 00 lea 0x0(%esi,%eiz,1),%esi
while ((*s++ = *t++) != 0) {
120: 0f b6 14 03 movzbl (%ebx,%eax,1),%edx
124: 88 14 01 mov %dl,(%ecx,%eax,1)
127: 83 c0 01 add $0x1,%eax
12a: 84 d2 test %dl,%dl
12c: 75 f2 jne 120 <strcpy+0x10>
;
}
return os;
}
12e: 8b 5d fc mov -0x4(%ebp),%ebx
131: 89 c8 mov %ecx,%eax
133: c9 leave
134: c3 ret
135: 8d b4 26 00 00 00 00 lea 0x0(%esi,%eiz,1),%esi
13c: 8d 74 26 00 lea 0x0(%esi,%eiz,1),%esi
00000140 <strcmp>:
int strcmp(const char *p, const char *q) {
140: 55 push %ebp
141: 89 e5 mov %esp,%ebp
143: 53 push %ebx
144: 8b 55 08 mov 0x8(%ebp),%edx
147: 8b 4d 0c mov 0xc(%ebp),%ecx
while (*p && *p == *q) {
14a: 0f b6 02 movzbl (%edx),%eax
14d: 84 c0 test %al,%al
14f: 75 17 jne 168 <strcmp+0x28>
151: eb 3a jmp 18d <strcmp+0x4d>
153: 8d 74 26 00 lea 0x0(%esi,%eiz,1),%esi
157: 90 nop
158: 0f b6 42 01 movzbl 0x1(%edx),%eax
p++, q++;
15c: 83 c2 01 add $0x1,%edx
15f: 8d 59 01 lea 0x1(%ecx),%ebx
while (*p && *p == *q) {
162: 84 c0 test %al,%al
164: 74 1a je 180 <strcmp+0x40>
p++, q++;
166: 89 d9 mov %ebx,%ecx
while (*p && *p == *q) {
168: 0f b6 19 movzbl (%ecx),%ebx
16b: 38 c3 cmp %al,%bl
16d: 74 e9 je 158 <strcmp+0x18>
}
return (uchar) * p - (uchar) * q;
16f: 29 d8 sub %ebx,%eax
}
171: 8b 5d fc mov -0x4(%ebp),%ebx
174: c9 leave
175: c3 ret
176: 8d b4 26 00 00 00 00 lea 0x0(%esi,%eiz,1),%esi
17d: 8d 76 00 lea 0x0(%esi),%esi
return (uchar) * p - (uchar) * q;
180: 0f b6 59 01 movzbl 0x1(%ecx),%ebx
184: 31 c0 xor %eax,%eax
186: 29 d8 sub %ebx,%eax
}
188: 8b 5d fc mov -0x4(%ebp),%ebx
18b: c9 leave
18c: c3 ret
return (uchar) * p - (uchar) * q;
18d: 0f b6 19 movzbl (%ecx),%ebx
190: 31 c0 xor %eax,%eax
192: eb db jmp 16f <strcmp+0x2f>
194: 8d b4 26 00 00 00 00 lea 0x0(%esi,%eiz,1),%esi
19b: 8d 74 26 00 lea 0x0(%esi,%eiz,1),%esi
19f: 90 nop
000001a0 <strlen>:
uint strlen(const char *s) {
1a0: 55 push %ebp
1a1: 89 e5 mov %esp,%ebp
1a3: 8b 55 08 mov 0x8(%ebp),%edx
int n;
for (n = 0; s[n]; n++) {
1a6: 80 3a 00 cmpb $0x0,(%edx)
1a9: 74 15 je 1c0 <strlen+0x20>
1ab: 31 c0 xor %eax,%eax
1ad: 8d 76 00 lea 0x0(%esi),%esi
1b0: 83 c0 01 add $0x1,%eax
1b3: 80 3c 02 00 cmpb $0x0,(%edx,%eax,1)
1b7: 89 c1 mov %eax,%ecx
1b9: 75 f5 jne 1b0 <strlen+0x10>
;
}
return n;
}
1bb: 89 c8 mov %ecx,%eax
1bd: 5d pop %ebp
1be: c3 ret
1bf: 90 nop
for (n = 0; s[n]; n++) {
1c0: 31 c9 xor %ecx,%ecx
}
1c2: 5d pop %ebp
1c3: 89 c8 mov %ecx,%eax
1c5: c3 ret
1c6: 8d b4 26 00 00 00 00 lea 0x0(%esi,%eiz,1),%esi
1cd: 8d 76 00 lea 0x0(%esi),%esi
000001d0 <memset>:
void* memset(void *dst, int c, uint n) {
1d0: 55 push %ebp
1d1: 89 e5 mov %esp,%ebp
1d3: 57 push %edi
1d4: 8b 55 08 mov 0x8(%ebp),%edx
"d" (port), "0" (addr), "1" (cnt) :
"cc");
}
static inline void stosb(void *addr, int data, int cnt) {
asm volatile ("cld; rep stosb" :
1d7: 8b 4d 10 mov 0x10(%ebp),%ecx
1da: 8b 45 0c mov 0xc(%ebp),%eax
1dd: 89 d7 mov %edx,%edi
1df: fc cld
1e0: f3 aa rep stos %al,%es:(%edi)
stosb(dst, c, n);
return dst;
}
1e2: 8b 7d fc mov -0x4(%ebp),%edi
1e5: 89 d0 mov %edx,%eax
1e7: c9 leave
1e8: c3 ret
1e9: 8d b4 26 00 00 00 00 lea 0x0(%esi,%eiz,1),%esi
000001f0 <strchr>:
char* strchr(const char *s, char c) {
1f0: 55 push %ebp
1f1: 89 e5 mov %esp,%ebp
1f3: 8b 45 08 mov 0x8(%ebp),%eax
1f6: 0f b6 4d 0c movzbl 0xc(%ebp),%ecx
for (; *s; s++) {
1fa: 0f b6 10 movzbl (%eax),%edx
1fd: 84 d2 test %dl,%dl
1ff: 75 12 jne 213 <strchr+0x23>
201: eb 1d jmp 220 <strchr+0x30>
203: 8d 74 26 00 lea 0x0(%esi,%eiz,1),%esi
207: 90 nop
208: 0f b6 50 01 movzbl 0x1(%eax),%edx
20c: 83 c0 01 add $0x1,%eax
20f: 84 d2 test %dl,%dl
211: 74 0d je 220 <strchr+0x30>
if (*s == c) {
213: 38 d1 cmp %dl,%cl
215: 75 f1 jne 208 <strchr+0x18>
return (char*)s;
}
}
return 0;
}
217: 5d pop %ebp
218: c3 ret
219: 8d b4 26 00 00 00 00 lea 0x0(%esi,%eiz,1),%esi
return 0;
220: 31 c0 xor %eax,%eax
}
222: 5d pop %ebp
223: c3 ret
224: 8d b4 26 00 00 00 00 lea 0x0(%esi,%eiz,1),%esi
22b: 8d 74 26 00 lea 0x0(%esi,%eiz,1),%esi
22f: 90 nop
00000230 <gets>:
char* gets(char *buf, int max) {
230: 55 push %ebp
231: 89 e5 mov %esp,%ebp
233: 57 push %edi
234: 56 push %esi
int i, cc;
char c;
for (i = 0; i + 1 < max;) {
cc = read(0, &c, 1);
235: 8d 7d e7 lea -0x19(%ebp),%edi
char* gets(char *buf, int max) {
238: 53 push %ebx
for (i = 0; i + 1 < max;) {
239: 31 db xor %ebx,%ebx
char* gets(char *buf, int max) {
23b: 83 ec 1c sub $0x1c,%esp
for (i = 0; i + 1 < max;) {
23e: eb 27 jmp 267 <gets+0x37>
cc = read(0, &c, 1);
240: 83 ec 04 sub $0x4,%esp
243: 6a 01 push $0x1
245: 57 push %edi
246: 6a 00 push $0x0
248: e8 2e 01 00 00 call 37b <read>
if (cc < 1) {
24d: 83 c4 10 add $0x10,%esp
250: 85 c0 test %eax,%eax
252: 7e 1d jle 271 <gets+0x41>
break;
}
buf[i++] = c;
254: 0f b6 45 e7 movzbl -0x19(%ebp),%eax
258: 8b 55 08 mov 0x8(%ebp),%edx
25b: 88 44 1a ff mov %al,-0x1(%edx,%ebx,1)
if (c == '\n' || c == '\r') {
25f: 3c 0a cmp $0xa,%al
261: 74 1d je 280 <gets+0x50>
263: 3c 0d cmp $0xd,%al
265: 74 19 je 280 <gets+0x50>
for (i = 0; i + 1 < max;) {
267: 89 de mov %ebx,%esi
269: 83 c3 01 add $0x1,%ebx
26c: 3b 5d 0c cmp 0xc(%ebp),%ebx
26f: 7c cf jl 240 <gets+0x10>
break;
}
}
buf[i] = '\0';
271: 8b 45 08 mov 0x8(%ebp),%eax
274: c6 04 30 00 movb $0x0,(%eax,%esi,1)
return buf;
}
278: 8d 65 f4 lea -0xc(%ebp),%esp
27b: 5b pop %ebx
27c: 5e pop %esi
27d: 5f pop %edi
27e: 5d pop %ebp
27f: c3 ret
buf[i] = '\0';
280: 8b 45 08 mov 0x8(%ebp),%eax
283: 89 de mov %ebx,%esi
285: c6 04 30 00 movb $0x0,(%eax,%esi,1)
}
289: 8d 65 f4 lea -0xc(%ebp),%esp
28c: 5b pop %ebx
28d: 5e pop %esi
28e: 5f pop %edi
28f: 5d pop %ebp
290: c3 ret
291: 8d b4 26 00 00 00 00 lea 0x0(%esi,%eiz,1),%esi
298: 8d b4 26 00 00 00 00 lea 0x0(%esi,%eiz,1),%esi
29f: 90 nop
000002a0 <stat>:
int stat(const char *n, struct stat *st) {
2a0: 55 push %ebp
2a1: 89 e5 mov %esp,%ebp
2a3: 56 push %esi
2a4: 53 push %ebx
int fd;
int r;
fd = open(n, O_RDONLY);
2a5: 83 ec 08 sub $0x8,%esp
2a8: 6a 00 push $0x0
2aa: ff 75 08 push 0x8(%ebp)
2ad: e8 19 01 00 00 call 3cb <open>
if (fd < 0) {
2b2: 83 c4 10 add $0x10,%esp
2b5: 85 c0 test %eax,%eax
2b7: 78 27 js 2e0 <stat+0x40>
return -1;
}
r = fstat(fd, st);
2b9: 83 ec 08 sub $0x8,%esp
2bc: ff 75 0c push 0xc(%ebp)
2bf: 89 c3 mov %eax,%ebx
2c1: 50 push %eax
2c2: e8 cc 00 00 00 call 393 <fstat>
close(fd);
2c7: 89 1c 24 mov %ebx,(%esp)
r = fstat(fd, st);
2ca: 89 c6 mov %eax,%esi
close(fd);
2cc: e8 2a 01 00 00 call 3fb <close>
return r;
2d1: 83 c4 10 add $0x10,%esp
}
2d4: 8d 65 f8 lea -0x8(%ebp),%esp
2d7: 89 f0 mov %esi,%eax
2d9: 5b pop %ebx
2da: 5e pop %esi
2db: 5d pop %ebp
2dc: c3 ret
2dd: 8d 76 00 lea 0x0(%esi),%esi
return -1;
2e0: be ff ff ff ff mov $0xffffffff,%esi
2e5: eb ed jmp 2d4 <stat+0x34>
2e7: 8d b4 26 00 00 00 00 lea 0x0(%esi,%eiz,1),%esi
2ee: 66 90 xchg %ax,%ax
000002f0 <atoi>:
int atoi(const char *s) {
2f0: 55 push %ebp
2f1: 89 e5 mov %esp,%ebp
2f3: 53 push %ebx
2f4: 8b 55 08 mov 0x8(%ebp),%edx
int n;
n = 0;
while ('0' <= *s && *s <= '9') {
2f7: 0f be 02 movsbl (%edx),%eax
2fa: 8d 48 d0 lea -0x30(%eax),%ecx
2fd: 80 f9 09 cmp $0x9,%cl
n = 0;
300: b9 00 00 00 00 mov $0x0,%ecx
while ('0' <= *s && *s <= '9') {
305: 77 1e ja 325 <atoi+0x35>
307: 8d b4 26 00 00 00 00 lea 0x0(%esi,%eiz,1),%esi
30e: 66 90 xchg %ax,%ax
n = n * 10 + *s++ - '0';
310: 83 c2 01 add $0x1,%edx
313: 8d 0c 89 lea (%ecx,%ecx,4),%ecx
316: 8d 4c 48 d0 lea -0x30(%eax,%ecx,2),%ecx
while ('0' <= *s && *s <= '9') {
31a: 0f be 02 movsbl (%edx),%eax
31d: 8d 58 d0 lea -0x30(%eax),%ebx
320: 80 fb 09 cmp $0x9,%bl
323: 76 eb jbe 310 <atoi+0x20>
}
return n;
}
325: 8b 5d fc mov -0x4(%ebp),%ebx
328: 89 c8 mov %ecx,%eax
32a: c9 leave
32b: c3 ret
32c: 8d 74 26 00 lea 0x0(%esi,%eiz,1),%esi
00000330 <memmove>:
void* memmove(void *vdst, const void *vsrc, int n) {
330: 55 push %ebp
331: 89 e5 mov %esp,%ebp
333: 57 push %edi
334: 8b 45 10 mov 0x10(%ebp),%eax
337: 8b 55 08 mov 0x8(%ebp),%edx
33a: 56 push %esi
33b: 8b 75 0c mov 0xc(%ebp),%esi
char *dst;
const char *src;
dst = vdst;
src = vsrc;
while (n-- > 0) {
33e: 85 c0 test %eax,%eax
340: 7e 13 jle 355 <memmove+0x25>
342: 01 d0 add %edx,%eax
dst = vdst;
344: 89 d7 mov %edx,%edi
346: 8d b4 26 00 00 00 00 lea 0x0(%esi,%eiz,1),%esi
34d: 8d 76 00 lea 0x0(%esi),%esi
*dst++ = *src++;
350: a4 movsb %ds:(%esi),%es:(%edi)
while (n-- > 0) {
351: 39 f8 cmp %edi,%eax
353: 75 fb jne 350 <memmove+0x20>
}
return vdst;
}
355: 5e pop %esi
356: 89 d0 mov %edx,%eax
358: 5f pop %edi
359: 5d pop %ebp
35a: c3 ret
0000035b <fork>:
name: \
movl $SYS_ ## name, %eax; \
int $T_SYSCALL; \
ret
SYSCALL(fork)
35b: b8 01 00 00 00 mov $0x1,%eax
360: cd 40 int $0x40
362: c3 ret
00000363 <exit>:
SYSCALL(exit)
363: b8 02 00 00 00 mov $0x2,%eax
368: cd 40 int $0x40
36a: c3 ret
0000036b <wait>:
SYSCALL(wait)
36b: b8 03 00 00 00 mov $0x3,%eax
370: cd 40 int $0x40
372: c3 ret
00000373 <pipe>:
SYSCALL(pipe)
373: b8 04 00 00 00 mov $0x4,%eax
378: cd 40 int $0x40
37a: c3 ret
0000037b <read>:
SYSCALL(read)
37b: b8 05 00 00 00 mov $0x5,%eax
380: cd 40 int $0x40
382: c3 ret
00000383 <kill>:
SYSCALL(kill)
383: b8 06 00 00 00 mov $0x6,%eax
388: cd 40 int $0x40
38a: c3 ret
0000038b <exec>:
SYSCALL(exec)
38b: b8 07 00 00 00 mov $0x7,%eax
390: cd 40 int $0x40
392: c3 ret
00000393 <fstat>:
SYSCALL(fstat)
393: b8 08 00 00 00 mov $0x8,%eax
398: cd 40 int $0x40
39a: c3 ret
0000039b <chdir>:
SYSCALL(chdir)
39b: b8 09 00 00 00 mov $0x9,%eax
3a0: cd 40 int $0x40
3a2: c3 ret
000003a3 <dup>:
SYSCALL(dup)
3a3: b8 0a 00 00 00 mov $0xa,%eax
3a8: cd 40 int $0x40
3aa: c3 ret
000003ab <getpid>:
SYSCALL(getpid)
3ab: b8 0b 00 00 00 mov $0xb,%eax
3b0: cd 40 int $0x40
3b2: c3 ret
000003b3 <sbrk>:
SYSCALL(sbrk)
3b3: b8 0c 00 00 00 mov $0xc,%eax
3b8: cd 40 int $0x40
3ba: c3 ret
000003bb <sleep>:
SYSCALL(sleep)
3bb: b8 0d 00 00 00 mov $0xd,%eax
3c0: cd 40 int $0x40
3c2: c3 ret
000003c3 <uptime>:
SYSCALL(uptime)
3c3: b8 0e 00 00 00 mov $0xe,%eax
3c8: cd 40 int $0x40
3ca: c3 ret
000003cb <open>:
SYSCALL(open)
3cb: b8 0f 00 00 00 mov $0xf,%eax
3d0: cd 40 int $0x40
3d2: c3 ret
000003d3 <write>:
SYSCALL(write)
3d3: b8 10 00 00 00 mov $0x10,%eax
3d8: cd 40 int $0x40
3da: c3 ret
000003db <mknod>:
SYSCALL(mknod)
3db: b8 11 00 00 00 mov $0x11,%eax
3e0: cd 40 int $0x40
3e2: c3 ret
000003e3 <unlink>:
SYSCALL(unlink)
3e3: b8 12 00 00 00 mov $0x12,%eax
3e8: cd 40 int $0x40
3ea: c3 ret
000003eb <link>:
SYSCALL(link)
3eb: b8 13 00 00 00 mov $0x13,%eax
3f0: cd 40 int $0x40
3f2: c3 ret
000003f3 <mkdir>:
SYSCALL(mkdir)
3f3: b8 14 00 00 00 mov $0x14,%eax
3f8: cd 40 int $0x40
3fa: c3 ret
000003fb <close>:
SYSCALL(close)
3fb: b8 15 00 00 00 mov $0x15,%eax
400: cd 40 int $0x40
402: c3 ret
00000403 <getch>:
SYSCALL(getch)
403: b8 16 00 00 00 mov $0x16,%eax
408: cd 40 int $0x40
40a: c3 ret
0000040b <greeting>:
SYSCALL(greeting)
40b: b8 17 00 00 00 mov $0x17,%eax
410: cd 40 int $0x40
412: c3 ret
00000413 <shutdown>:
SYSCALL(shutdown)
413: b8 18 00 00 00 mov $0x18,%eax
418: cd 40 int $0x40
41a: c3 ret
0000041b <screen>:
SYSCALL(screen)
41b: b8 19 00 00 00 mov $0x19,%eax
420: cd 40 int $0x40
422: c3 ret
00000423 <cls>:
SYSCALL(cls)
423: b8 1a 00 00 00 mov $0x1a,%eax
428: cd 40 int $0x40
42a: c3 ret
42b: 66 90 xchg %ax,%ax
42d: 66 90 xchg %ax,%ax
42f: 90 nop
00000430 <printint>:
static void putc(int fd, char c) {
write(fd, &c, 1);
}
static void printint(int fd, int xx, int base, int sgn) {
430: 55 push %ebp
431: 89 e5 mov %esp,%ebp
433: 57 push %edi
434: 56 push %esi
435: 53 push %ebx
436: 83 ec 3c sub $0x3c,%esp
439: 89 4d c4 mov %ecx,-0x3c(%ebp)
uint x;
neg = 0;
if (sgn && xx < 0) {
neg = 1;
x = -xx;
43c: 89 d1 mov %edx,%ecx
static void printint(int fd, int xx, int base, int sgn) {
43e: 89 45 b8 mov %eax,-0x48(%ebp)
if (sgn && xx < 0) {
441: 85 d2 test %edx,%edx
443: 0f 89 7f 00 00 00 jns 4c8 <printint+0x98>
449: f6 45 08 01 testb $0x1,0x8(%ebp)
44d: 74 79 je 4c8 <printint+0x98>
neg = 1;
44f: c7 45 bc 01 00 00 00 movl $0x1,-0x44(%ebp)
x = -xx;
456: f7 d9 neg %ecx
}
else {
x = xx;
}
i = 0;
458: 31 db xor %ebx,%ebx
45a: 8d 75 d7 lea -0x29(%ebp),%esi
45d: 8d 76 00 lea 0x0(%esi),%esi
do {
buf[i++] = digits[x % base];
460: 89 c8 mov %ecx,%eax
462: 31 d2 xor %edx,%edx
464: 89 cf mov %ecx,%edi
466: f7 75 c4 divl -0x3c(%ebp)
469: 0f b6 92 a0 08 00 00 movzbl 0x8a0(%edx),%edx
470: 89 45 c0 mov %eax,-0x40(%ebp)
473: 89 d8 mov %ebx,%eax
475: 8d 5b 01 lea 0x1(%ebx),%ebx
}
while ((x /= base) != 0);
478: 8b 4d c0 mov -0x40(%ebp),%ecx
buf[i++] = digits[x % base];
47b: 88 14 1e mov %dl,(%esi,%ebx,1)
while ((x /= base) != 0);
47e: 39 7d c4 cmp %edi,-0x3c(%ebp)
481: 76 dd jbe 460 <printint+0x30>
if (neg) {
483: 8b 4d bc mov -0x44(%ebp),%ecx
486: 85 c9 test %ecx,%ecx
488: 74 0c je 496 <printint+0x66>
buf[i++] = '-';
48a: c6 44 1d d8 2d movb $0x2d,-0x28(%ebp,%ebx,1)
buf[i++] = digits[x % base];
48f: 89 d8 mov %ebx,%eax
buf[i++] = '-';
491: ba 2d 00 00 00 mov $0x2d,%edx
}
while (--i >= 0) {
496: 8b 7d b8 mov -0x48(%ebp),%edi
499: 8d 5c 05 d7 lea -0x29(%ebp,%eax,1),%ebx
49d: eb 07 jmp 4a6 <printint+0x76>
49f: 90 nop
putc(fd, buf[i]);
4a0: 0f b6 13 movzbl (%ebx),%edx
4a3: 83 eb 01 sub $0x1,%ebx
write(fd, &c, 1);
4a6: 83 ec 04 sub $0x4,%esp
4a9: 88 55 d7 mov %dl,-0x29(%ebp)
4ac: 6a 01 push $0x1
4ae: 56 push %esi
4af: 57 push %edi
4b0: e8 1e ff ff ff call 3d3 <write>
while (--i >= 0) {
4b5: 83 c4 10 add $0x10,%esp
4b8: 39 de cmp %ebx,%esi
4ba: 75 e4 jne 4a0 <printint+0x70>
}
}
4bc: 8d 65 f4 lea -0xc(%ebp),%esp
4bf: 5b pop %ebx
4c0: 5e pop %esi
4c1: 5f pop %edi
4c2: 5d pop %ebp
4c3: c3 ret
4c4: 8d 74 26 00 lea 0x0(%esi,%eiz,1),%esi
neg = 0;
4c8: c7 45 bc 00 00 00 00 movl $0x0,-0x44(%ebp)
4cf: eb 87 jmp 458 <printint+0x28>
4d1: 8d b4 26 00 00 00 00 lea 0x0(%esi,%eiz,1),%esi
4d8: 8d b4 26 00 00 00 00 lea 0x0(%esi,%eiz,1),%esi
4df: 90 nop
000004e0 <printf>:
// Print to the given fd. Only understands %d, %x, %p, %s.
void printf(int fd, const char *fmt, ...) {
4e0: 55 push %ebp
4e1: 89 e5 mov %esp,%ebp
4e3: 57 push %edi
4e4: 56 push %esi
4e5: 53 push %ebx
4e6: 83 ec 2c sub $0x2c,%esp
int c, i, state;
uint *ap;
state = 0;
ap = (uint*)(void*)&fmt + 1;
for (i = 0; fmt[i]; i++) {
4e9: 8b 5d 0c mov 0xc(%ebp),%ebx
void printf(int fd, const char *fmt, ...) {
4ec: 8b 75 08 mov 0x8(%ebp),%esi
for (i = 0; fmt[i]; i++) {
4ef: 0f b6 13 movzbl (%ebx),%edx
4f2: 84 d2 test %dl,%dl
4f4: 74 6a je 560 <printf+0x80>
ap = (uint*)(void*)&fmt + 1;
4f6: 8d 45 10 lea 0x10(%ebp),%eax
4f9: 83 c3 01 add $0x1,%ebx
write(fd, &c, 1);
4fc: 8d 7d e7 lea -0x19(%ebp),%edi
state = 0;
4ff: 31 c9 xor %ecx,%ecx
ap = (uint*)(void*)&fmt + 1;
501: 89 45 d0 mov %eax,-0x30(%ebp)
504: eb 36 jmp 53c <printf+0x5c>
506: 8d b4 26 00 00 00 00 lea 0x0(%esi,%eiz,1),%esi
50d: 8d 76 00 lea 0x0(%esi),%esi
510: 89 4d d4 mov %ecx,-0x2c(%ebp)
c = fmt[i] & 0xff;
if (state == 0) {
if (c == '%') {
state = '%';
513: b9 25 00 00 00 mov $0x25,%ecx
if (c == '%') {
518: 83 f8 25 cmp $0x25,%eax
51b: 74 15 je 532 <printf+0x52>
write(fd, &c, 1);
51d: 83 ec 04 sub $0x4,%esp
520: 88 55 e7 mov %dl,-0x19(%ebp)
523: 6a 01 push $0x1
525: 57 push %edi
526: 56 push %esi
527: e8 a7 fe ff ff call 3d3 <write>
52c: 8b 4d d4 mov -0x2c(%ebp),%ecx
}
else {
putc(fd, c);
52f: 83 c4 10 add $0x10,%esp
for (i = 0; fmt[i]; i++) {
532: 0f b6 13 movzbl (%ebx),%edx
535: 83 c3 01 add $0x1,%ebx
538: 84 d2 test %dl,%dl
53a: 74 24 je 560 <printf+0x80>
c = fmt[i] & 0xff;
53c: 0f b6 c2 movzbl %dl,%eax
if (state == 0) {
53f: 85 c9 test %ecx,%ecx
541: 74 cd je 510 <printf+0x30>
}
}
else if (state == '%') {
543: 83 f9 25 cmp $0x25,%ecx
546: 75 ea jne 532 <printf+0x52>
if (c == 'd') {
548: 83 f8 25 cmp $0x25,%eax
54b: 0f 84 07 01 00 00 je 658 <printf+0x178>
551: 83 e8 63 sub $0x63,%eax
554: 83 f8 15 cmp $0x15,%eax
557: 77 17 ja 570 <printf+0x90>
559: ff 24 85 48 08 00 00 jmp *0x848(,%eax,4)
putc(fd, c);
}
state = 0;
}
}
}
560: 8d 65 f4 lea -0xc(%ebp),%esp
563: 5b pop %ebx
564: 5e pop %esi
565: 5f pop %edi
566: 5d pop %ebp
567: c3 ret
568: 8d b4 26 00 00 00 00 lea 0x0(%esi,%eiz,1),%esi
56f: 90 nop
write(fd, &c, 1);
570: 83 ec 04 sub $0x4,%esp
573: 88 55 d4 mov %dl,-0x2c(%ebp)
576: 6a 01 push $0x1
578: 57 push %edi
579: 56 push %esi
57a: c6 45 e7 25 movb $0x25,-0x19(%ebp)
57e: e8 50 fe ff ff call 3d3 <write>
putc(fd, c);
583: 0f b6 55 d4 movzbl -0x2c(%ebp),%edx
write(fd, &c, 1);
587: 83 c4 0c add $0xc,%esp
58a: 88 55 e7 mov %dl,-0x19(%ebp)
58d: 6a 01 push $0x1
58f: 57 push %edi
590: 56 push %esi
591: e8 3d fe ff ff call 3d3 <write>
putc(fd, c);
596: 83 c4 10 add $0x10,%esp
state = 0;
599: 31 c9 xor %ecx,%ecx
59b: eb 95 jmp 532 <printf+0x52>
59d: 8d 76 00 lea 0x0(%esi),%esi
printint(fd, *ap, 16, 0);
5a0: 83 ec 0c sub $0xc,%esp
5a3: b9 10 00 00 00 mov $0x10,%ecx
5a8: 6a 00 push $0x0
5aa: 8b 45 d0 mov -0x30(%ebp),%eax
5ad: 8b 10 mov (%eax),%edx
5af: 89 f0 mov %esi,%eax
5b1: e8 7a fe ff ff call 430 <printint>
ap++;
5b6: 83 45 d0 04 addl $0x4,-0x30(%ebp)
5ba: 83 c4 10 add $0x10,%esp
state = 0;
5bd: 31 c9 xor %ecx,%ecx
5bf: e9 6e ff ff ff jmp 532 <printf+0x52>
5c4: 8d 74 26 00 lea 0x0(%esi,%eiz,1),%esi
s = (char*)*ap;
5c8: 8b 45 d0 mov -0x30(%ebp),%eax
5cb: 8b 10 mov (%eax),%edx
ap++;
5cd: 83 c0 04 add $0x4,%eax
5d0: 89 45 d0 mov %eax,-0x30(%ebp)
if (s == 0) {
5d3: 85 d2 test %edx,%edx
5d5: 0f 84 8d 00 00 00 je 668 <printf+0x188>
while (*s != 0) {
5db: 0f b6 02 movzbl (%edx),%eax
state = 0;
5de: 31 c9 xor %ecx,%ecx
while (*s != 0) {
5e0: 84 c0 test %al,%al
5e2: 0f 84 4a ff ff ff je 532 <printf+0x52>
5e8: 89 5d d4 mov %ebx,-0x2c(%ebp)
5eb: 89 d3 mov %edx,%ebx
5ed: 8d 76 00 lea 0x0(%esi),%esi
write(fd, &c, 1);
5f0: 83 ec 04 sub $0x4,%esp
s++;
5f3: 83 c3 01 add $0x1,%ebx
5f6: 88 45 e7 mov %al,-0x19(%ebp)
write(fd, &c, 1);
5f9: 6a 01 push $0x1
5fb: 57 push %edi
5fc: 56 push %esi
5fd: e8 d1 fd ff ff call 3d3 <write>
while (*s != 0) {
602: 0f b6 03 movzbl (%ebx),%eax
605: 83 c4 10 add $0x10,%esp
608: 84 c0 test %al,%al
60a: 75 e4 jne 5f0 <printf+0x110>
state = 0;
60c: 8b 5d d4 mov -0x2c(%ebp),%ebx
60f: 31 c9 xor %ecx,%ecx
611: e9 1c ff ff ff jmp 532 <printf+0x52>
616: 8d b4 26 00 00 00 00 lea 0x0(%esi,%eiz,1),%esi
61d: 8d 76 00 lea 0x0(%esi),%esi
printint(fd, *ap, 10, 1);
620: 83 ec 0c sub $0xc,%esp
623: b9 0a 00 00 00 mov $0xa,%ecx
628: 6a 01 push $0x1
62a: e9 7b ff ff ff jmp 5aa <printf+0xca>
62f: 90 nop
putc(fd, *ap);
630: 8b 45 d0 mov -0x30(%ebp),%eax
write(fd, &c, 1);
633: 83 ec 04 sub $0x4,%esp
putc(fd, *ap);
636: 8b 00 mov (%eax),%eax
write(fd, &c, 1);
638: 6a 01 push $0x1
63a: 57 push %edi
63b: 56 push %esi
putc(fd, *ap);
63c: 88 45 e7 mov %al,-0x19(%ebp)
write(fd, &c, 1);
63f: e8 8f fd ff ff call 3d3 <write>
ap++;
644: 83 45 d0 04 addl $0x4,-0x30(%ebp)
648: 83 c4 10 add $0x10,%esp
state = 0;
64b: 31 c9 xor %ecx,%ecx
64d: e9 e0 fe ff ff jmp 532 <printf+0x52>
652: 8d b6 00 00 00 00 lea 0x0(%esi),%esi
putc(fd, c);
658: 88 55 e7 mov %dl,-0x19(%ebp)
write(fd, &c, 1);
65b: 83 ec 04 sub $0x4,%esp
65e: e9 2a ff ff ff jmp 58d <printf+0xad>
663: 8d 74 26 00 lea 0x0(%esi,%eiz,1),%esi
667: 90 nop
s = "(null)";
668: ba 40 08 00 00 mov $0x840,%edx
while (*s != 0) {
66d: 89 5d d4 mov %ebx,-0x2c(%ebp)
670: b8 28 00 00 00 mov $0x28,%eax
675: 89 d3 mov %edx,%ebx
677: e9 74 ff ff ff jmp 5f0 <printf+0x110>
67c: 66 90 xchg %ax,%ax
67e: 66 90 xchg %ax,%ax
00000680 <free>:
typedef union header Header;
static Header base;
static Header *freep;
void free(void *ap) {
680: 55 push %ebp
Header *bp, *p;
bp = (Header*)ap - 1;
for (p = freep; !(bp > p && bp < p->s.ptr); p = p->s.ptr) {
681: a1 a0 0d 00 00 mov 0xda0,%eax
void free(void *ap) {
686: 89 e5 mov %esp,%ebp
688: 57 push %edi
689: 56 push %esi
68a: 53 push %ebx
68b: 8b 5d 08 mov 0x8(%ebp),%ebx
bp = (Header*)ap - 1;
68e: 8d 4b f8 lea -0x8(%ebx),%ecx
for (p = freep; !(bp > p && bp < p->s.ptr); p = p->s.ptr) {
691: 8d b4 26 00 00 00 00 lea 0x0(%esi,%eiz,1),%esi
698: 89 c2 mov %eax,%edx
69a: 8b 00 mov (%eax),%eax
69c: 39 ca cmp %ecx,%edx
69e: 73 30 jae 6d0 <free+0x50>
6a0: 39 c1 cmp %eax,%ecx
6a2: 72 04 jb 6a8 <free+0x28>
if (p >= p->s.ptr && (bp > p || bp < p->s.ptr)) {
6a4: 39 c2 cmp %eax,%edx
6a6: 72 f0 jb 698 <free+0x18>
break;
}
}
if (bp + bp->s.size == p->s.ptr) {
6a8: 8b 73 fc mov -0x4(%ebx),%esi
6ab: 8d 3c f1 lea (%ecx,%esi,8),%edi
6ae: 39 f8 cmp %edi,%eax
6b0: 74 30 je 6e2 <free+0x62>
bp->s.size += p->s.ptr->s.size;
bp->s.ptr = p->s.ptr->s.ptr;
6b2: 89 43 f8 mov %eax,-0x8(%ebx)
}
else {
bp->s.ptr = p->s.ptr;
}
if (p + p->s.size == bp) {
6b5: 8b 42 04 mov 0x4(%edx),%eax
6b8: 8d 34 c2 lea (%edx,%eax,8),%esi
6bb: 39 f1 cmp %esi,%ecx
6bd: 74 3a je 6f9 <free+0x79>
p->s.size += bp->s.size;
p->s.ptr = bp->s.ptr;
6bf: 89 0a mov %ecx,(%edx)
}
else {
p->s.ptr = bp;
}
freep = p;
}
6c1: 5b pop %ebx
freep = p;
6c2: 89 15 a0 0d 00 00 mov %edx,0xda0
}
6c8: 5e pop %esi
6c9: 5f pop %edi
6ca: 5d pop %ebp
6cb: c3 ret
6cc: 8d 74 26 00 lea 0x0(%esi,%eiz,1),%esi
if (p >= p->s.ptr && (bp > p || bp < p->s.ptr)) {
6d0: 39 c2 cmp %eax,%edx
6d2: 72 c4 jb 698 <free+0x18>
6d4: 39 c1 cmp %eax,%ecx
6d6: 73 c0 jae 698 <free+0x18>
if (bp + bp->s.size == p->s.ptr) {
6d8: 8b 73 fc mov -0x4(%ebx),%esi
6db: 8d 3c f1 lea (%ecx,%esi,8),%edi
6de: 39 f8 cmp %edi,%eax
6e0: 75 d0 jne 6b2 <free+0x32>
bp->s.size += p->s.ptr->s.size;
6e2: 03 70 04 add 0x4(%eax),%esi
6e5: 89 73 fc mov %esi,-0x4(%ebx)
bp->s.ptr = p->s.ptr->s.ptr;
6e8: 8b 02 mov (%edx),%eax
6ea: 8b 00 mov (%eax),%eax
6ec: 89 43 f8 mov %eax,-0x8(%ebx)
if (p + p->s.size == bp) {
6ef: 8b 42 04 mov 0x4(%edx),%eax
6f2: 8d 34 c2 lea (%edx,%eax,8),%esi
6f5: 39 f1 cmp %esi,%ecx
6f7: 75 c6 jne 6bf <free+0x3f>
p->s.size += bp->s.size;
6f9: 03 43 fc add -0x4(%ebx),%eax
freep = p;
6fc: 89 15 a0 0d 00 00 mov %edx,0xda0
p->s.size += bp->s.size;
702: 89 42 04 mov %eax,0x4(%edx)
p->s.ptr = bp->s.ptr;
705: 8b 4b f8 mov -0x8(%ebx),%ecx
708: 89 0a mov %ecx,(%edx)
}
70a: 5b pop %ebx
70b: 5e pop %esi
70c: 5f pop %edi
70d: 5d pop %ebp
70e: c3 ret
70f: 90 nop
00000710 <malloc>:
hp->s.size = nu;
free((void*)(hp + 1));
return freep;
}
void* malloc(uint nbytes) {
710: 55 push %ebp
711: 89 e5 mov %esp,%ebp
713: 57 push %edi
714: 56 push %esi
715: 53 push %ebx
716: 83 ec 1c sub $0x1c,%esp
Header *p, *prevp;
uint nunits;
nunits = (nbytes + sizeof(Header) - 1) / sizeof(Header) + 1;
719: 8b 45 08 mov 0x8(%ebp),%eax
if ((prevp = freep) == 0) {
71c: 8b 3d a0 0d 00 00 mov 0xda0,%edi
nunits = (nbytes + sizeof(Header) - 1) / sizeof(Header) + 1;
722: 8d 70 07 lea 0x7(%eax),%esi
725: c1 ee 03 shr $0x3,%esi
728: 83 c6 01 add $0x1,%esi
if ((prevp = freep) == 0) {
72b: 85 ff test %edi,%edi
72d: 0f 84 9d 00 00 00 je 7d0 <malloc+0xc0>
base.s.ptr = freep = prevp = &base;
base.s.size = 0;
}
for (p = prevp->s.ptr;; prevp = p, p = p->s.ptr) {
733: 8b 17 mov (%edi),%edx
if (p->s.size >= nunits) {
735: 8b 4a 04 mov 0x4(%edx),%ecx
738: 39 f1 cmp %esi,%ecx
73a: 73 6a jae 7a6 <malloc+0x96>
73c: bb 00 10 00 00 mov $0x1000,%ebx
741: 39 de cmp %ebx,%esi
743: 0f 43 de cmovae %esi,%ebx
p = sbrk(nu * sizeof(Header));
746: 8d 04 dd 00 00 00 00 lea 0x0(,%ebx,8),%eax
74d: 89 45 e4 mov %eax,-0x1c(%ebp)
750: eb 17 jmp 769 <malloc+0x59>
752: 8d b6 00 00 00 00 lea 0x0(%esi),%esi
for (p = prevp->s.ptr;; prevp = p, p = p->s.ptr) {
758: 8b 02 mov (%edx),%eax
if (p->s.size >= nunits) {
75a: 8b 48 04 mov 0x4(%eax),%ecx
75d: 39 f1 cmp %esi,%ecx
75f: 73 4f jae 7b0 <malloc+0xa0>
p->s.size = nunits;
}
freep = prevp;
return (void*)(p + 1);
}
if (p == freep) {
761: 8b 3d a0 0d 00 00 mov 0xda0,%edi
767: 89 c2 mov %eax,%edx
769: 39 d7 cmp %edx,%edi
76b: 75 eb jne 758 <malloc+0x48>
p = sbrk(nu * sizeof(Header));
76d: 83 ec 0c sub $0xc,%esp
770: ff 75 e4 push -0x1c(%ebp)
773: e8 3b fc ff ff call 3b3 <sbrk>
if (p == (char*)-1) {
778: 83 c4 10 add $0x10,%esp
77b: 83 f8 ff cmp $0xffffffff,%eax
77e: 74 1c je 79c <malloc+0x8c>
hp->s.size = nu;
780: 89 58 04 mov %ebx,0x4(%eax)
free((void*)(hp + 1));
783: 83 ec 0c sub $0xc,%esp
786: 83 c0 08 add $0x8,%eax
789: 50 push %eax
78a: e8 f1 fe ff ff call 680 <free>
return freep;
78f: 8b 15 a0 0d 00 00 mov 0xda0,%edx
if ((p = morecore(nunits)) == 0) {
795: 83 c4 10 add $0x10,%esp
798: 85 d2 test %edx,%edx
79a: 75 bc jne 758 <malloc+0x48>
return 0;
}
}
}
}
79c: 8d 65 f4 lea -0xc(%ebp),%esp
return 0;
79f: 31 c0 xor %eax,%eax
}
7a1: 5b pop %ebx
7a2: 5e pop %esi
7a3: 5f pop %edi
7a4: 5d pop %ebp
7a5: c3 ret
if (p->s.size >= nunits) {
7a6: 89 d0 mov %edx,%eax
7a8: 89 fa mov %edi,%edx
7aa: 8d b6 00 00 00 00 lea 0x0(%esi),%esi
if (p->s.size == nunits) {
7b0: 39 ce cmp %ecx,%esi
7b2: 74 4c je 800 <malloc+0xf0>
p->s.size -= nunits;
7b4: 29 f1 sub %esi,%ecx
7b6: 89 48 04 mov %ecx,0x4(%eax)
p += p->s.size;
7b9: 8d 04 c8 lea (%eax,%ecx,8),%eax
p->s.size = nunits;
7bc: 89 70 04 mov %esi,0x4(%eax)
freep = prevp;
7bf: 89 15 a0 0d 00 00 mov %edx,0xda0
}
7c5: 8d 65 f4 lea -0xc(%ebp),%esp
return (void*)(p + 1);
7c8: 83 c0 08 add $0x8,%eax
}
7cb: 5b pop %ebx
7cc: 5e pop %esi
7cd: 5f pop %edi
7ce: 5d pop %ebp
7cf: c3 ret
base.s.ptr = freep = prevp = &base;
7d0: c7 05 a0 0d 00 00 a4 movl $0xda4,0xda0
7d7: 0d 00 00
base.s.size = 0;
7da: bf a4 0d 00 00 mov $0xda4,%edi
base.s.ptr = freep = prevp = &base;
7df: c7 05 a4 0d 00 00 a4 movl $0xda4,0xda4
7e6: 0d 00 00
for (p = prevp->s.ptr;; prevp = p, p = p->s.ptr) {
7e9: 89 fa mov %edi,%edx
base.s.size = 0;
7eb: c7 05 a8 0d 00 00 00 movl $0x0,0xda8
7f2: 00 00 00
if (p->s.size >= nunits) {
7f5: e9 42 ff ff ff jmp 73c <malloc+0x2c>
7fa: 8d b6 00 00 00 00 lea 0x0(%esi),%esi
prevp->s.ptr = p->s.ptr;
800: 8b 08 mov (%eax),%ecx
802: 89 0a mov %ecx,(%edx)
804: eb b9 jmp 7bf <malloc+0xaf>