_cat: file format elf32-littlearm Disassembly of section .text: 00000000
: int main(int argc, char *argv[]) { int fd, i; if(argc <= 1){ 0: e3500001 cmp r0, #1 } } int main(int argc, char *argv[]) { 4: e92d49f8 push {r3, r4, r5, r6, r7, r8, fp, lr} 8: e1a07000 mov r7, r0 c: e28db01c add fp, sp, #28 exit(); } } int main(int argc, char *argv[]) 10: c2814004 addgt r4, r1, #4 14: c3a05001 movgt r5, #1 { int fd, i; if(argc <= 1){ 18: da000012 ble 68 cat(0); exit(); } for(i = 1; i < argc; i++){ if((fd = open(argv[i], 0)) < 0){ 1c: e5940000 ldr r0, [r4] 20: e3a01000 mov r1, #0 24: eb000137 bl 508 28: e1a06004 mov r6, r4 2c: e2844004 add r4, r4, #4 30: e2508000 subs r8, r0, #0 34: ba000006 blt 54 printf(1, "cat: cannot open %s\n", argv[i]); exit(); } cat(fd); 38: eb00000e bl 78 if(argc <= 1){ cat(0); exit(); } for(i = 1; i < argc; i++){ 3c: e2855001 add r5, r5, #1 if((fd = open(argv[i], 0)) < 0){ printf(1, "cat: cannot open %s\n", argv[i]); exit(); } cat(fd); close(fd); 40: e1a00008 mov r0, r8 44: eb000108 bl 46c if(argc <= 1){ cat(0); exit(); } for(i = 1; i < argc; i++){ 48: e1550007 cmp r5, r7 4c: 1afffff2 bne 1c exit(); } cat(fd); close(fd); } exit(); 50: eb0000c4 bl 368 exit(); } for(i = 1; i < argc; i++){ if((fd = open(argv[i], 0)) < 0){ printf(1, "cat: cannot open %s\n", argv[i]); 54: e3a00001 mov r0, #1 58: e59f1014 ldr r1, [pc, #20] ; 74 5c: e5962000 ldr r2, [r6] 60: eb000213 bl 8b4 exit(); 64: eb0000bf bl 368 main(int argc, char *argv[]) { int fd, i; if(argc <= 1){ cat(0); 68: e3a00000 mov r0, #0 6c: eb000001 bl 78 exit(); 70: eb0000bc bl 368 74: 00000bb0 .word 0x00000bb0 00000078 : char buf[512]; void cat(int fd) { 78: e92d4818 push {r3, r4, fp, lr} 7c: e1a04000 mov r4, r0 80: e28db00c add fp, sp, #12 int n; while((n = read(fd, buf, sizeof(buf))) > 0) 84: ea000002 b 94 write(1, buf, n); 88: e3a00001 mov r0, #1 8c: e59f102c ldr r1, [pc, #44] ; c0 90: eb0000e8 bl 438 void cat(int fd) { int n; while((n = read(fd, buf, sizeof(buf))) > 0) 94: e3a02c02 mov r2, #512 ; 0x200 98: e1a00004 mov r0, r4 9c: e59f101c ldr r1, [pc, #28] ; c0 a0: eb0000d7 bl 404 a4: e2502000 subs r2, r0, #0 a8: cafffff6 bgt 88 write(1, buf, n); if(n < 0){ ac: 08bd8818 popeq {r3, r4, fp, pc} printf(1, "cat: read error\n"); b0: e3a00001 mov r0, #1 b4: e59f1008 ldr r1, [pc, #8] ; c4 b8: eb0001fd bl 8b4 exit(); bc: eb0000a9 bl 368 c0: 00000bf0 .word 0x00000bf0 c4: 00000b9c .word 0x00000b9c 000000c8 : #include "user.h" #include "arm.h" char* strcpy(char *s, char *t) { c8: e52db004 push {fp} ; (str fp, [sp, #-4]!) char *os; os = s; while((*s++ = *t++) != 0) cc: e1a02000 mov r2, r0 #include "user.h" #include "arm.h" char* strcpy(char *s, char *t) { d0: e28db000 add fp, sp, #0 char *os; os = s; while((*s++ = *t++) != 0) d4: e4d13001 ldrb r3, [r1], #1 d8: e3530000 cmp r3, #0 dc: e4c23001 strb r3, [r2], #1 e0: 1afffffb bne d4 ; return os; } e4: e28bd000 add sp, fp, #0 e8: e8bd0800 pop {fp} ec: e12fff1e bx lr 000000f0 : int strcmp(const char *p, const char *q) { f0: e52db004 push {fp} ; (str fp, [sp, #-4]!) f4: e28db000 add fp, sp, #0 while(*p && *p == *q) f8: e5d03000 ldrb r3, [r0] fc: e5d12000 ldrb r2, [r1] 100: e3530000 cmp r3, #0 104: 1a000004 bne 11c 108: ea000005 b 124 10c: e5f03001 ldrb r3, [r0, #1]! 110: e3530000 cmp r3, #0 114: 0a000006 beq 134 118: e5f12001 ldrb r2, [r1, #1]! 11c: e1530002 cmp r3, r2 120: 0afffff9 beq 10c p++, q++; return (uchar)*p - (uchar)*q; } 124: e0620003 rsb r0, r2, r3 128: e28bd000 add sp, fp, #0 12c: e8bd0800 pop {fp} 130: e12fff1e bx lr } int strcmp(const char *p, const char *q) { while(*p && *p == *q) 134: e5d12001 ldrb r2, [r1, #1] 138: eafffff9 b 124 0000013c : return (uchar)*p - (uchar)*q; } uint strlen(char *s) { 13c: e52db004 push {fp} ; (str fp, [sp, #-4]!) 140: e28db000 add fp, sp, #0 int n; for(n = 0; s[n]; n++) 144: e5d03000 ldrb r3, [r0] 148: e3530000 cmp r3, #0 14c: 01a00003 moveq r0, r3 150: 0a000006 beq 170 154: e1a02000 mov r2, r0 158: e3a03000 mov r3, #0 15c: e5f21001 ldrb r1, [r2, #1]! 160: e2833001 add r3, r3, #1 164: e1a00003 mov r0, r3 168: e3510000 cmp r1, #0 16c: 1afffffa bne 15c ; return n; } 170: e28bd000 add sp, fp, #0 174: e8bd0800 pop {fp} 178: e12fff1e bx lr 0000017c : memset(void *dst, int c, uint n) { char *p=dst; u32 rc=n; while (rc-- > 0) *p++ = c; 17c: e3520000 cmp r2, #0 return n; } void* memset(void *dst, int c, uint n) { 180: e52db004 push {fp} ; (str fp, [sp, #-4]!) 184: e28db000 add fp, sp, #0 char *p=dst; u32 rc=n; while (rc-- > 0) *p++ = c; 188: 0a000006 beq 1a8 18c: e6ef1071 uxtb r1, r1 190: e1a03002 mov r3, r2 } void* memset(void *dst, int c, uint n) { char *p=dst; 194: e1a0c000 mov ip, r0 u32 rc=n; while (rc-- > 0) *p++ = c; 198: e2533001 subs r3, r3, #1 19c: e4cc1001 strb r1, [ip], #1 1a0: 1afffffc bne 198 1a4: e0800002 add r0, r0, r2 return (void *)p; } 1a8: e28bd000 add sp, fp, #0 1ac: e8bd0800 pop {fp} 1b0: e12fff1e bx lr 000001b4 : char* strchr(const char *s, char c) { 1b4: e52db004 push {fp} ; (str fp, [sp, #-4]!) 1b8: e28db000 add fp, sp, #0 for(; *s; s++) 1bc: e5d03000 ldrb r3, [r0] 1c0: e3530000 cmp r3, #0 1c4: 1a000004 bne 1dc 1c8: ea000008 b 1f0 1cc: e5d03001 ldrb r3, [r0, #1] 1d0: e2800001 add r0, r0, #1 1d4: e3530000 cmp r3, #0 1d8: 0a000004 beq 1f0 if(*s == c) 1dc: e1530001 cmp r3, r1 1e0: 1afffff9 bne 1cc return (char*)s; return 0; } 1e4: e28bd000 add sp, fp, #0 1e8: e8bd0800 pop {fp} 1ec: e12fff1e bx lr strchr(const char *s, char c) { for(; *s; s++) if(*s == c) return (char*)s; return 0; 1f0: e1a00003 mov r0, r3 1f4: eafffffa b 1e4 000001f8 : } char* gets(char *buf, int max) { 1f8: e92d49f0 push {r4, r5, r6, r7, r8, fp, lr} 1fc: e28db018 add fp, sp, #24 200: e24dd00c sub sp, sp, #12 204: e1a08000 mov r8, r0 208: e1a07001 mov r7, r1 int i, cc; char c; for(i=0; i+1 < max; ){ 20c: e1a06000 mov r6, r0 210: e3a05000 mov r5, #0 214: ea000008 b 23c cc = read(0, &c, 1); 218: eb000079 bl 404 if(cc < 1) 21c: e3500000 cmp r0, #0 220: da00000b ble 254 break; buf[i++] = c; 224: e55b301d ldrb r3, [fp, #-29] if(c == '\n' || c == '\r') 228: e1a05004 mov r5, r4 22c: e353000a cmp r3, #10 230: 1353000d cmpne r3, #13 for(i=0; i+1 < max; ){ cc = read(0, &c, 1); if(cc < 1) break; buf[i++] = c; 234: e4c63001 strb r3, [r6], #1 if(c == '\n' || c == '\r') 238: 0a00000a beq 268 { int i, cc; char c; for(i=0; i+1 < max; ){ cc = read(0, &c, 1); 23c: e3a02001 mov r2, #1 gets(char *buf, int max) { int i, cc; char c; for(i=0; i+1 < max; ){ 240: e0854002 add r4, r5, r2 244: e1540007 cmp r4, r7 cc = read(0, &c, 1); 248: e3a00000 mov r0, #0 24c: e24b101d sub r1, fp, #29 gets(char *buf, int max) { int i, cc; char c; for(i=0; i+1 < max; ){ 250: bafffff0 blt 218 break; buf[i++] = c; if(c == '\n' || c == '\r') break; } buf[i] = '\0'; 254: e3a03000 mov r3, #0 258: e7c83005 strb r3, [r8, r5] return buf; } 25c: e1a00008 mov r0, r8 260: e24bd018 sub sp, fp, #24 264: e8bd89f0 pop {r4, r5, r6, r7, r8, fp, pc} gets(char *buf, int max) { int i, cc; char c; for(i=0; i+1 < max; ){ 268: e1a05004 mov r5, r4 26c: eafffff8 b 254 00000270 : return buf; } int stat(char *n, struct stat *st) { 270: e92d4830 push {r4, r5, fp, lr} 274: e1a05001 mov r5, r1 278: e28db00c add fp, sp, #12 int fd; int r; fd = open(n, O_RDONLY); 27c: e3a01000 mov r1, #0 280: eb0000a0 bl 508 if(fd < 0) 284: e2504000 subs r4, r0, #0 return -1; 288: b3e05000 mvnlt r5, #0 { int fd; int r; fd = open(n, O_RDONLY); if(fd < 0) 28c: ba000004 blt 2a4 return -1; r = fstat(fd, st); 290: e1a01005 mov r1, r5 294: eb0000c2 bl 5a4 298: e1a05000 mov r5, r0 close(fd); 29c: e1a00004 mov r0, r4 2a0: eb000071 bl 46c return r; } 2a4: e1a00005 mov r0, r5 2a8: e8bd8830 pop {r4, r5, fp, pc} 000002ac : int atoi(const char *s) { 2ac: e52db004 push {fp} ; (str fp, [sp, #-4]!) 2b0: e28db000 add fp, sp, #0 int n; n = 0; while('0' <= *s && *s <= '9') 2b4: e5d03000 ldrb r3, [r0] 2b8: e2432030 sub r2, r3, #48 ; 0x30 2bc: e6ef2072 uxtb r2, r2 2c0: e3520009 cmp r2, #9 int atoi(const char *s) { int n; n = 0; 2c4: 83a00000 movhi r0, #0 while('0' <= *s && *s <= '9') 2c8: 8a000009 bhi 2f4 2cc: e1a02000 mov r2, r0 int atoi(const char *s) { int n; n = 0; 2d0: e3a00000 mov r0, #0 while('0' <= *s && *s <= '9') n = n*10 + *s++ - '0'; 2d4: e0800100 add r0, r0, r0, lsl #2 2d8: e0830080 add r0, r3, r0, lsl #1 atoi(const char *s) { int n; n = 0; while('0' <= *s && *s <= '9') 2dc: e5f23001 ldrb r3, [r2, #1]! n = n*10 + *s++ - '0'; 2e0: e2400030 sub r0, r0, #48 ; 0x30 atoi(const char *s) { int n; n = 0; while('0' <= *s && *s <= '9') 2e4: e2431030 sub r1, r3, #48 ; 0x30 2e8: e6ef1071 uxtb r1, r1 2ec: e3510009 cmp r1, #9 2f0: 9afffff7 bls 2d4 n = n*10 + *s++ - '0'; return n; } 2f4: e28bd000 add sp, fp, #0 2f8: e8bd0800 pop {fp} 2fc: e12fff1e bx lr 00000300 : { char *dst, *src; dst = vdst; src = vsrc; while(n-- > 0) 300: e3520000 cmp r2, #0 return n; } void* memmove(void *vdst, void *vsrc, int n) { 304: e52db004 push {fp} ; (str fp, [sp, #-4]!) 308: e28db000 add fp, sp, #0 char *dst, *src; dst = vdst; src = vsrc; while(n-- > 0) 30c: da000005 ble 328 n = n*10 + *s++ - '0'; return n; } void* memmove(void *vdst, void *vsrc, int n) 310: e0802002 add r2, r0, r2 { char *dst, *src; dst = vdst; 314: e1a03000 mov r3, r0 src = vsrc; while(n-- > 0) *dst++ = *src++; 318: e4d1c001 ldrb ip, [r1], #1 31c: e4c3c001 strb ip, [r3], #1 { char *dst, *src; dst = vdst; src = vsrc; while(n-- > 0) 320: e1530002 cmp r3, r2 324: 1afffffb bne 318 *dst++ = *src++; return vdst; } 328: e28bd000 add sp, fp, #0 32c: e8bd0800 pop {fp} 330: e12fff1e bx lr 00000334 : 334: e92d4000 push {lr} 338: e92d0008 push {r3} 33c: e92d0004 push {r2} 340: e92d0002 push {r1} 344: e92d0001 push {r0} 348: e3a00001 mov r0, #1 34c: ef000040 svc 0x00000040 350: e8bd0002 pop {r1} 354: e8bd0002 pop {r1} 358: e8bd0004 pop {r2} 35c: e8bd0008 pop {r3} 360: e8bd4000 pop {lr} 364: e12fff1e bx lr 00000368 : 368: e92d4000 push {lr} 36c: e92d0008 push {r3} 370: e92d0004 push {r2} 374: e92d0002 push {r1} 378: e92d0001 push {r0} 37c: e3a00002 mov r0, #2 380: ef000040 svc 0x00000040 384: e8bd0002 pop {r1} 388: e8bd0002 pop {r1} 38c: e8bd0004 pop {r2} 390: e8bd0008 pop {r3} 394: e8bd4000 pop {lr} 398: e12fff1e bx lr 0000039c : 39c: e92d4000 push {lr} 3a0: e92d0008 push {r3} 3a4: e92d0004 push {r2} 3a8: e92d0002 push {r1} 3ac: e92d0001 push {r0} 3b0: e3a00003 mov r0, #3 3b4: ef000040 svc 0x00000040 3b8: e8bd0002 pop {r1} 3bc: e8bd0002 pop {r1} 3c0: e8bd0004 pop {r2} 3c4: e8bd0008 pop {r3} 3c8: e8bd4000 pop {lr} 3cc: e12fff1e bx lr 000003d0 : 3d0: e92d4000 push {lr} 3d4: e92d0008 push {r3} 3d8: e92d0004 push {r2} 3dc: e92d0002 push {r1} 3e0: e92d0001 push {r0} 3e4: e3a00004 mov r0, #4 3e8: ef000040 svc 0x00000040 3ec: e8bd0002 pop {r1} 3f0: e8bd0002 pop {r1} 3f4: e8bd0004 pop {r2} 3f8: e8bd0008 pop {r3} 3fc: e8bd4000 pop {lr} 400: e12fff1e bx lr 00000404 : 404: e92d4000 push {lr} 408: e92d0008 push {r3} 40c: e92d0004 push {r2} 410: e92d0002 push {r1} 414: e92d0001 push {r0} 418: e3a00005 mov r0, #5 41c: ef000040 svc 0x00000040 420: e8bd0002 pop {r1} 424: e8bd0002 pop {r1} 428: e8bd0004 pop {r2} 42c: e8bd0008 pop {r3} 430: e8bd4000 pop {lr} 434: e12fff1e bx lr 00000438 : 438: e92d4000 push {lr} 43c: e92d0008 push {r3} 440: e92d0004 push {r2} 444: e92d0002 push {r1} 448: e92d0001 push {r0} 44c: e3a00010 mov r0, #16 450: ef000040 svc 0x00000040 454: e8bd0002 pop {r1} 458: e8bd0002 pop {r1} 45c: e8bd0004 pop {r2} 460: e8bd0008 pop {r3} 464: e8bd4000 pop {lr} 468: e12fff1e bx lr 0000046c : 46c: e92d4000 push {lr} 470: e92d0008 push {r3} 474: e92d0004 push {r2} 478: e92d0002 push {r1} 47c: e92d0001 push {r0} 480: e3a00015 mov r0, #21 484: ef000040 svc 0x00000040 488: e8bd0002 pop {r1} 48c: e8bd0002 pop {r1} 490: e8bd0004 pop {r2} 494: e8bd0008 pop {r3} 498: e8bd4000 pop {lr} 49c: e12fff1e bx lr 000004a0 : 4a0: e92d4000 push {lr} 4a4: e92d0008 push {r3} 4a8: e92d0004 push {r2} 4ac: e92d0002 push {r1} 4b0: e92d0001 push {r0} 4b4: e3a00006 mov r0, #6 4b8: ef000040 svc 0x00000040 4bc: e8bd0002 pop {r1} 4c0: e8bd0002 pop {r1} 4c4: e8bd0004 pop {r2} 4c8: e8bd0008 pop {r3} 4cc: e8bd4000 pop {lr} 4d0: e12fff1e bx lr 000004d4 : 4d4: e92d4000 push {lr} 4d8: e92d0008 push {r3} 4dc: e92d0004 push {r2} 4e0: e92d0002 push {r1} 4e4: e92d0001 push {r0} 4e8: e3a00007 mov r0, #7 4ec: ef000040 svc 0x00000040 4f0: e8bd0002 pop {r1} 4f4: e8bd0002 pop {r1} 4f8: e8bd0004 pop {r2} 4fc: e8bd0008 pop {r3} 500: e8bd4000 pop {lr} 504: e12fff1e bx lr 00000508 : 508: e92d4000 push {lr} 50c: e92d0008 push {r3} 510: e92d0004 push {r2} 514: e92d0002 push {r1} 518: e92d0001 push {r0} 51c: e3a0000f mov r0, #15 520: ef000040 svc 0x00000040 524: e8bd0002 pop {r1} 528: e8bd0002 pop {r1} 52c: e8bd0004 pop {r2} 530: e8bd0008 pop {r3} 534: e8bd4000 pop {lr} 538: e12fff1e bx lr 0000053c : 53c: e92d4000 push {lr} 540: e92d0008 push {r3} 544: e92d0004 push {r2} 548: e92d0002 push {r1} 54c: e92d0001 push {r0} 550: e3a00011 mov r0, #17 554: ef000040 svc 0x00000040 558: e8bd0002 pop {r1} 55c: e8bd0002 pop {r1} 560: e8bd0004 pop {r2} 564: e8bd0008 pop {r3} 568: e8bd4000 pop {lr} 56c: e12fff1e bx lr 00000570 : 570: e92d4000 push {lr} 574: e92d0008 push {r3} 578: e92d0004 push {r2} 57c: e92d0002 push {r1} 580: e92d0001 push {r0} 584: e3a00012 mov r0, #18 588: ef000040 svc 0x00000040 58c: e8bd0002 pop {r1} 590: e8bd0002 pop {r1} 594: e8bd0004 pop {r2} 598: e8bd0008 pop {r3} 59c: e8bd4000 pop {lr} 5a0: e12fff1e bx lr 000005a4 : 5a4: e92d4000 push {lr} 5a8: e92d0008 push {r3} 5ac: e92d0004 push {r2} 5b0: e92d0002 push {r1} 5b4: e92d0001 push {r0} 5b8: e3a00008 mov r0, #8 5bc: ef000040 svc 0x00000040 5c0: e8bd0002 pop {r1} 5c4: e8bd0002 pop {r1} 5c8: e8bd0004 pop {r2} 5cc: e8bd0008 pop {r3} 5d0: e8bd4000 pop {lr} 5d4: e12fff1e bx lr 000005d8 : 5d8: e92d4000 push {lr} 5dc: e92d0008 push {r3} 5e0: e92d0004 push {r2} 5e4: e92d0002 push {r1} 5e8: e92d0001 push {r0} 5ec: e3a00013 mov r0, #19 5f0: ef000040 svc 0x00000040 5f4: e8bd0002 pop {r1} 5f8: e8bd0002 pop {r1} 5fc: e8bd0004 pop {r2} 600: e8bd0008 pop {r3} 604: e8bd4000 pop {lr} 608: e12fff1e bx lr 0000060c : 60c: e92d4000 push {lr} 610: e92d0008 push {r3} 614: e92d0004 push {r2} 618: e92d0002 push {r1} 61c: e92d0001 push {r0} 620: e3a00014 mov r0, #20 624: ef000040 svc 0x00000040 628: e8bd0002 pop {r1} 62c: e8bd0002 pop {r1} 630: e8bd0004 pop {r2} 634: e8bd0008 pop {r3} 638: e8bd4000 pop {lr} 63c: e12fff1e bx lr 00000640 : 640: e92d4000 push {lr} 644: e92d0008 push {r3} 648: e92d0004 push {r2} 64c: e92d0002 push {r1} 650: e92d0001 push {r0} 654: e3a00009 mov r0, #9 658: ef000040 svc 0x00000040 65c: e8bd0002 pop {r1} 660: e8bd0002 pop {r1} 664: e8bd0004 pop {r2} 668: e8bd0008 pop {r3} 66c: e8bd4000 pop {lr} 670: e12fff1e bx lr 00000674 : 674: e92d4000 push {lr} 678: e92d0008 push {r3} 67c: e92d0004 push {r2} 680: e92d0002 push {r1} 684: e92d0001 push {r0} 688: e3a0000a mov r0, #10 68c: ef000040 svc 0x00000040 690: e8bd0002 pop {r1} 694: e8bd0002 pop {r1} 698: e8bd0004 pop {r2} 69c: e8bd0008 pop {r3} 6a0: e8bd4000 pop {lr} 6a4: e12fff1e bx lr 000006a8 : 6a8: e92d4000 push {lr} 6ac: e92d0008 push {r3} 6b0: e92d0004 push {r2} 6b4: e92d0002 push {r1} 6b8: e92d0001 push {r0} 6bc: e3a0000b mov r0, #11 6c0: ef000040 svc 0x00000040 6c4: e8bd0002 pop {r1} 6c8: e8bd0002 pop {r1} 6cc: e8bd0004 pop {r2} 6d0: e8bd0008 pop {r3} 6d4: e8bd4000 pop {lr} 6d8: e12fff1e bx lr 000006dc : 6dc: e92d4000 push {lr} 6e0: e92d0008 push {r3} 6e4: e92d0004 push {r2} 6e8: e92d0002 push {r1} 6ec: e92d0001 push {r0} 6f0: e3a0000c mov r0, #12 6f4: ef000040 svc 0x00000040 6f8: e8bd0002 pop {r1} 6fc: e8bd0002 pop {r1} 700: e8bd0004 pop {r2} 704: e8bd0008 pop {r3} 708: e8bd4000 pop {lr} 70c: e12fff1e bx lr 00000710 : 710: e92d4000 push {lr} 714: e92d0008 push {r3} 718: e92d0004 push {r2} 71c: e92d0002 push {r1} 720: e92d0001 push {r0} 724: e3a0000d mov r0, #13 728: ef000040 svc 0x00000040 72c: e8bd0002 pop {r1} 730: e8bd0002 pop {r1} 734: e8bd0004 pop {r2} 738: e8bd0008 pop {r3} 73c: e8bd4000 pop {lr} 740: e12fff1e bx lr 00000744 : 744: e92d4000 push {lr} 748: e92d0008 push {r3} 74c: e92d0004 push {r2} 750: e92d0002 push {r1} 754: e92d0001 push {r0} 758: e3a0000e mov r0, #14 75c: ef000040 svc 0x00000040 760: e8bd0002 pop {r1} 764: e8bd0002 pop {r1} 768: e8bd0004 pop {r2} 76c: e8bd0008 pop {r3} 770: e8bd4000 pop {lr} 774: e12fff1e bx lr 00000778 : #include "stat.h" #include "user.h" static void putc(int fd, char c) { 778: e92d4800 push {fp, lr} 77c: e28db004 add fp, sp, #4 780: e24b3004 sub r3, fp, #4 784: e24dd008 sub sp, sp, #8 write(fd, &c, 1); 788: e3a02001 mov r2, #1 #include "stat.h" #include "user.h" static void putc(int fd, char c) { 78c: e5631001 strb r1, [r3, #-1]! write(fd, &c, 1); 790: e1a01003 mov r1, r3 794: ebffff27 bl 438 } 798: e24bd004 sub sp, fp, #4 79c: e8bd8800 pop {fp, pc} 000007a0 : return q; } static void printint(int fd, int xx, int base, int sgn) { 7a0: e92d4ff0 push {r4, r5, r6, r7, r8, r9, sl, fp, lr} 7a4: e1a04000 mov r4, r0 char buf[16]; int i, neg; uint x, y, b; neg = 0; if(sgn && xx < 0){ 7a8: e1a00fa1 lsr r0, r1, #31 7ac: e3530000 cmp r3, #0 7b0: 03a03000 moveq r3, #0 7b4: 12003001 andne r3, r0, #1 return q; } static void printint(int fd, int xx, int base, int sgn) { 7b8: e28db020 add fp, sp, #32 char buf[16]; int i, neg; uint x, y, b; neg = 0; if(sgn && xx < 0){ 7bc: e3530000 cmp r3, #0 return q; } static void printint(int fd, int xx, int base, int sgn) { 7c0: e24dd014 sub sp, sp, #20 7c4: e59f909c ldr r9, [pc, #156] ; 868 uint x, y, b; neg = 0; if(sgn && xx < 0){ neg = 1; x = -xx; 7c8: 12611000 rsbne r1, r1, #0 int i, neg; uint x, y, b; neg = 0; if(sgn && xx < 0){ neg = 1; 7cc: 13a03001 movne r3, #1 } else { x = xx; } b = base; i = 0; 7d0: e3a0a000 mov sl, #0 7d4: e24b6034 sub r6, fp, #52 ; 0x34 for(i=31;i>=0;i--){ r = r << 1; r = r | ((n >> i) & 1); if(r >= d) { r = r - d; q = q | (1 << i); 7d8: e3a08001 mov r8, #1 write(fd, &c, 1); } u32 div(u32 n, u32 d) // long division { u32 q=0, r=0; 7dc: e3a07000 mov r7, #0 int i; for(i=31;i>=0;i--){ 7e0: e3a0001f mov r0, #31 write(fd, &c, 1); } u32 div(u32 n, u32 d) // long division { u32 q=0, r=0; 7e4: e1a0c007 mov ip, r7 int i; for(i=31;i>=0;i--){ r = r << 1; r = r | ((n >> i) & 1); 7e8: e1a0e031 lsr lr, r1, r0 7ec: e20ee001 and lr, lr, #1 7f0: e18ec08c orr ip, lr, ip, lsl #1 if(r >= d) { 7f4: e152000c cmp r2, ip r = r - d; q = q | (1 << i); 7f8: 91877018 orrls r7, r7, r8, lsl r0 for(i=31;i>=0;i--){ r = r << 1; r = r | ((n >> i) & 1); if(r >= d) { r = r - d; 7fc: 9062c00c rsbls ip, r2, ip u32 div(u32 n, u32 d) // long division { u32 q=0, r=0; int i; for(i=31;i>=0;i--){ 800: e2500001 subs r0, r0, #1 804: 2afffff7 bcs 7e8 b = base; i = 0; do{ y = div(x, b); buf[i++] = digits[x - y * b]; 808: e0000792 mul r0, r2, r7 }while((x = y) != 0); 80c: e3570000 cmp r7, #0 b = base; i = 0; do{ y = div(x, b); buf[i++] = digits[x - y * b]; 810: e0601001 rsb r1, r0, r1 814: e28a5001 add r5, sl, #1 818: e7d91001 ldrb r1, [r9, r1] 81c: e7c6100a strb r1, [r6, sl] }while((x = y) != 0); 820: 11a01007 movne r1, r7 b = base; i = 0; do{ y = div(x, b); buf[i++] = digits[x - y * b]; 824: 11a0a005 movne sl, r5 828: 1affffeb bne 7dc }while((x = y) != 0); if(neg) 82c: e3530000 cmp r3, #0 buf[i++] = '-'; 830: 124b2024 subne r2, fp, #36 ; 0x24 834: 10823005 addne r3, r2, r5 838: 128a5002 addne r5, sl, #2 while(--i >= 0) 83c: e2455001 sub r5, r5, #1 do{ y = div(x, b); buf[i++] = digits[x - y * b]; }while((x = y) != 0); if(neg) buf[i++] = '-'; 840: 13a0202d movne r2, #45 ; 0x2d 844: 15432010 strbne r2, [r3, #-16] while(--i >= 0) putc(fd, buf[i]); 848: e7d61005 ldrb r1, [r6, r5] 84c: e1a00004 mov r0, r4 buf[i++] = digits[x - y * b]; }while((x = y) != 0); if(neg) buf[i++] = '-'; while(--i >= 0) 850: e2455001 sub r5, r5, #1 putc(fd, buf[i]); 854: ebffffc7 bl 778 buf[i++] = digits[x - y * b]; }while((x = y) != 0); if(neg) buf[i++] = '-'; while(--i >= 0) 858: e3750001 cmn r5, #1 85c: 1afffff9 bne 848 putc(fd, buf[i]); } 860: e24bd020 sub sp, fp, #32 864: e8bd8ff0 pop {r4, r5, r6, r7, r8, r9, sl, fp, pc} 868: 00000bc8 .word 0x00000bc8 0000086c
: write(fd, &c, 1); } u32 div(u32 n, u32 d) // long division { u32 q=0, r=0; 86c: e3a03000 mov r3, #0 { write(fd, &c, 1); } u32 div(u32 n, u32 d) // long division { 870: e92d0830 push {r4, r5, fp} 874: e1a02000 mov r2, r0 878: e28db008 add fp, sp, #8 u32 q=0, r=0; int i; for(i=31;i>=0;i--){ 87c: e3a0c01f mov ip, #31 write(fd, &c, 1); } u32 div(u32 n, u32 d) // long division { u32 q=0, r=0; 880: e1a00003 mov r0, r3 for(i=31;i>=0;i--){ r = r << 1; r = r | ((n >> i) & 1); if(r >= d) { r = r - d; q = q | (1 << i); 884: e3a05001 mov r5, #1 u32 q=0, r=0; int i; for(i=31;i>=0;i--){ r = r << 1; r = r | ((n >> i) & 1); 888: e1a04c32 lsr r4, r2, ip 88c: e2044001 and r4, r4, #1 890: e1843083 orr r3, r4, r3, lsl #1 if(r >= d) { 894: e1530001 cmp r3, r1 r = r - d; q = q | (1 << i); 898: 21800c15 orrcs r0, r0, r5, lsl ip for(i=31;i>=0;i--){ r = r << 1; r = r | ((n >> i) & 1); if(r >= d) { r = r - d; 89c: 20613003 rsbcs r3, r1, r3 u32 div(u32 n, u32 d) // long division { u32 q=0, r=0; int i; for(i=31;i>=0;i--){ 8a0: e25cc001 subs ip, ip, #1 8a4: 2afffff7 bcs 888 r = r - d; q = q | (1 << i); } } return q; } 8a8: e24bd008 sub sp, fp, #8 8ac: e8bd0830 pop {r4, r5, fp} 8b0: e12fff1e bx lr 000008b4 : } // Print to the given fd. Only understands %d, %x, %p, %s. void printf(int fd, char *fmt, ...) { 8b4: e92d000e push {r1, r2, r3} 8b8: e92d4ff0 push {r4, r5, r6, r7, r8, r9, sl, fp, lr} 8bc: e28db020 add fp, sp, #32 8c0: e1a05000 mov r5, r0 int c, i, state; uint *ap; state = 0; ap = (uint*)(void*)&fmt + 1; for(i = 0; fmt[i]; i++){ 8c4: e59b4004 ldr r4, [fp, #4] 8c8: e5d48000 ldrb r8, [r4] 8cc: e3580000 cmp r8, #0 8d0: 0a000027 beq 974 ap++; } else if(c == 's'){ s = (char*)*ap; ap++; if(s == 0) s = "(null)"; 8d4: e59f712c ldr r7, [pc, #300] ; a08 char *s; int c, i, state; uint *ap; state = 0; ap = (uint*)(void*)&fmt + 1; 8d8: e28b6008 add r6, fp, #8 { char *s; int c, i, state; uint *ap; state = 0; 8dc: e3a0a000 mov sl, #0 8e0: ea000008 b 908 ap = (uint*)(void*)&fmt + 1; for(i = 0; fmt[i]; i++){ c = fmt[i] & 0xff; if(state == 0){ if(c == '%'){ 8e4: e3580025 cmp r8, #37 ; 0x25 state = '%'; 8e8: 01a0a008 moveq sl, r8 state = 0; ap = (uint*)(void*)&fmt + 1; for(i = 0; fmt[i]; i++){ c = fmt[i] & 0xff; if(state == 0){ if(c == '%'){ 8ec: 0a000002 beq 8fc state = '%'; } else { putc(fd, c); 8f0: e1a00005 mov r0, r5 8f4: e1a01008 mov r1, r8 8f8: ebffff9e bl 778 int c, i, state; uint *ap; state = 0; ap = (uint*)(void*)&fmt + 1; for(i = 0; fmt[i]; i++){ 8fc: e5f48001 ldrb r8, [r4, #1]! 900: e3580000 cmp r8, #0 904: 0a00001a beq 974 c = fmt[i] & 0xff; if(state == 0){ 908: e35a0000 cmp sl, #0 90c: 0afffff4 beq 8e4 if(c == '%'){ state = '%'; } else { putc(fd, c); } } else if(state == '%'){ 910: e35a0025 cmp sl, #37 ; 0x25 914: 1afffff8 bne 8fc if(c == 'd'){ 918: e3580064 cmp r8, #100 ; 0x64 91c: 0a00002c beq 9d4 printint(fd, *ap, 10, 1); ap++; } else if(c == 'x' || c == 'p'){ 920: e3580078 cmp r8, #120 ; 0x78 924: 13580070 cmpne r8, #112 ; 0x70 928: 13a09000 movne r9, #0 92c: 03a09001 moveq r9, #1 930: 0a000013 beq 984 printint(fd, *ap, 16, 0); ap++; } else if(c == 's'){ 934: e3580073 cmp r8, #115 ; 0x73 938: 0a000018 beq 9a0 s = "(null)"; while(*s != 0){ putc(fd, *s); s++; } } else if(c == 'c'){ 93c: e3580063 cmp r8, #99 ; 0x63 940: 0a00002a beq 9f0 putc(fd, *ap); ap++; } else if(c == '%'){ 944: e3580025 cmp r8, #37 ; 0x25 putc(fd, c); 948: e1a0100a mov r1, sl 94c: e1a00005 mov r0, r5 s++; } } else if(c == 'c'){ putc(fd, *ap); ap++; } else if(c == '%'){ 950: 0a000002 beq 960 putc(fd, c); } else { // Unknown % sequence. Print it to draw attention. putc(fd, '%'); 954: ebffff87 bl 778 putc(fd, c); 958: e1a00005 mov r0, r5 95c: e1a01008 mov r1, r8 960: ebffff84 bl 778 int c, i, state; uint *ap; state = 0; ap = (uint*)(void*)&fmt + 1; for(i = 0; fmt[i]; i++){ 964: e5f48001 ldrb r8, [r4, #1]! } else { // Unknown % sequence. Print it to draw attention. putc(fd, '%'); putc(fd, c); } state = 0; 968: e1a0a009 mov sl, r9 int c, i, state; uint *ap; state = 0; ap = (uint*)(void*)&fmt + 1; for(i = 0; fmt[i]; i++){ 96c: e3580000 cmp r8, #0 970: 1affffe4 bne 908 putc(fd, c); } state = 0; } } } 974: e24bd020 sub sp, fp, #32 978: e8bd4ff0 pop {r4, r5, r6, r7, r8, r9, sl, fp, lr} 97c: e28dd00c add sp, sp, #12 980: e12fff1e bx lr } else if(state == '%'){ if(c == 'd'){ printint(fd, *ap, 10, 1); ap++; } else if(c == 'x' || c == 'p'){ printint(fd, *ap, 16, 0); 984: e1a00005 mov r0, r5 988: e4961004 ldr r1, [r6], #4 98c: e3a02010 mov r2, #16 990: e3a03000 mov r3, #0 994: ebffff81 bl 7a0 } else { // Unknown % sequence. Print it to draw attention. putc(fd, '%'); putc(fd, c); } state = 0; 998: e3a0a000 mov sl, #0 99c: eaffffd6 b 8fc ap++; } else if(c == 'x' || c == 'p'){ printint(fd, *ap, 16, 0); ap++; } else if(c == 's'){ s = (char*)*ap; 9a0: e4968004 ldr r8, [r6], #4 ap++; if(s == 0) s = "(null)"; 9a4: e3580000 cmp r8, #0 9a8: 01a08007 moveq r8, r7 while(*s != 0){ 9ac: e5d81000 ldrb r1, [r8] 9b0: e3510000 cmp r1, #0 9b4: 0a000004 beq 9cc putc(fd, *s); 9b8: e1a00005 mov r0, r5 9bc: ebffff6d bl 778 } else if(c == 's'){ s = (char*)*ap; ap++; if(s == 0) s = "(null)"; while(*s != 0){ 9c0: e5f81001 ldrb r1, [r8, #1]! 9c4: e3510000 cmp r1, #0 9c8: 1afffffa bne 9b8 } else { // Unknown % sequence. Print it to draw attention. putc(fd, '%'); putc(fd, c); } state = 0; 9cc: e1a0a001 mov sl, r1 9d0: eaffffc9 b 8fc } else { putc(fd, c); } } else if(state == '%'){ if(c == 'd'){ printint(fd, *ap, 10, 1); 9d4: e1a00005 mov r0, r5 9d8: e4961004 ldr r1, [r6], #4 9dc: e3a0200a mov r2, #10 9e0: e3a03001 mov r3, #1 9e4: ebffff6d bl 7a0 } else { // Unknown % sequence. Print it to draw attention. putc(fd, '%'); putc(fd, c); } state = 0; 9e8: e3a0a000 mov sl, #0 9ec: eaffffc2 b 8fc while(*s != 0){ putc(fd, *s); s++; } } else if(c == 'c'){ putc(fd, *ap); 9f0: e4961004 ldr r1, [r6], #4 9f4: e1a00005 mov r0, r5 } else { // Unknown % sequence. Print it to draw attention. putc(fd, '%'); putc(fd, c); } state = 0; 9f8: e1a0a009 mov sl, r9 while(*s != 0){ putc(fd, *s); s++; } } else if(c == 'c'){ putc(fd, *ap); 9fc: e6ef1071 uxtb r1, r1 a00: ebffff5c bl 778 a04: eaffffbc b 8fc a08: 00000bdc .word 0x00000bdc 00000a0c : free(void *ap) { Header *bp, *p; bp = (Header*)ap - 1; for(p = freep; !(bp > p && bp < p->s.ptr); p = p->s.ptr) a0c: e59f3098 ldr r3, [pc, #152] ; aac static Header base; static Header *freep; void free(void *ap) { a10: e92d0830 push {r4, r5, fp} Header *bp, *p; bp = (Header*)ap - 1; a14: e240c008 sub ip, r0, #8 for(p = freep; !(bp > p && bp < p->s.ptr); p = p->s.ptr) a18: e5932000 ldr r2, [r3] static Header base; static Header *freep; void free(void *ap) { a1c: e28db008 add fp, sp, #8 Header *bp, *p; bp = (Header*)ap - 1; for(p = freep; !(bp > p && bp < p->s.ptr); p = p->s.ptr) a20: e152000c cmp r2, ip a24: e5921000 ldr r1, [r2] a28: 2a000001 bcs a34 a2c: e15c0001 cmp ip, r1 a30: 3a000007 bcc a54 if(p >= p->s.ptr && (bp > p || bp < p->s.ptr)) a34: e1520001 cmp r2, r1 a38: 3a000003 bcc a4c a3c: e152000c cmp r2, ip a40: 3a000003 bcc a54 a44: e15c0001 cmp ip, r1 a48: 3a000001 bcc a54 static Header base; static Header *freep; void free(void *ap) { a4c: e1a02001 mov r2, r1 a50: eafffff2 b a20 bp = (Header*)ap - 1; for(p = freep; !(bp > p && bp < p->s.ptr); p = p->s.ptr) if(p >= p->s.ptr && (bp > p || bp < p->s.ptr)) break; if(bp + bp->s.size == p->s.ptr){ a54: e5104004 ldr r4, [r0, #-4] if(p + p->s.size == bp){ p->s.size += bp->s.size; p->s.ptr = bp->s.ptr; } else p->s.ptr = bp; freep = p; a58: e5832000 str r2, [r3] bp = (Header*)ap - 1; for(p = freep; !(bp > p && bp < p->s.ptr); p = p->s.ptr) if(p >= p->s.ptr && (bp > p || bp < p->s.ptr)) break; if(bp + bp->s.size == p->s.ptr){ a5c: e08c5184 add r5, ip, r4, lsl #3 a60: e1550001 cmp r5, r1 bp->s.size += p->s.ptr->s.size; a64: 05911004 ldreq r1, [r1, #4] a68: 00814004 addeq r4, r1, r4 a6c: 05004004 streq r4, [r0, #-4] bp->s.ptr = p->s.ptr->s.ptr; a70: 05921000 ldreq r1, [r2] a74: 05911000 ldreq r1, [r1] } else bp->s.ptr = p->s.ptr; a78: e5001008 str r1, [r0, #-8] if(p + p->s.size == bp){ a7c: e5921004 ldr r1, [r2, #4] a80: e0824181 add r4, r2, r1, lsl #3 a84: e15c0004 cmp ip, r4 p->s.size += bp->s.size; p->s.ptr = bp->s.ptr; } else p->s.ptr = bp; a88: 1582c000 strne ip, [r2] bp->s.size += p->s.ptr->s.size; bp->s.ptr = p->s.ptr->s.ptr; } else bp->s.ptr = p->s.ptr; if(p + p->s.size == bp){ p->s.size += bp->s.size; a8c: 0510c004 ldreq ip, [r0, #-4] a90: 008c1001 addeq r1, ip, r1 a94: 05821004 streq r1, [r2, #4] p->s.ptr = bp->s.ptr; a98: 05101008 ldreq r1, [r0, #-8] a9c: 05821000 streq r1, [r2] } else p->s.ptr = bp; freep = p; } aa0: e24bd008 sub sp, fp, #8 aa4: e8bd0830 pop {r4, r5, fp} aa8: e12fff1e bx lr aac: 00000be4 .word 0x00000be4 00000ab0 : return freep; } void* malloc(uint nbytes) { ab0: e92d49f8 push {r3, r4, r5, r6, r7, r8, fp, lr} Header *p, *prevp; uint nunits; nunits = (nbytes + sizeof(Header) - 1)/sizeof(Header) + 1; ab4: e2804007 add r4, r0, #7 if((prevp = freep) == 0){ ab8: e59f50d4 ldr r5, [pc, #212] ; b94 malloc(uint nbytes) { Header *p, *prevp; uint nunits; nunits = (nbytes + sizeof(Header) - 1)/sizeof(Header) + 1; abc: e1a041a4 lsr r4, r4, #3 return freep; } void* malloc(uint nbytes) { ac0: e28db01c add fp, sp, #28 Header *p, *prevp; uint nunits; nunits = (nbytes + sizeof(Header) - 1)/sizeof(Header) + 1; if((prevp = freep) == 0){ ac4: e5953000 ldr r3, [r5] malloc(uint nbytes) { Header *p, *prevp; uint nunits; nunits = (nbytes + sizeof(Header) - 1)/sizeof(Header) + 1; ac8: e2844001 add r4, r4, #1 if((prevp = freep) == 0){ acc: e3530000 cmp r3, #0 ad0: 0a00002b beq b84 ad4: e5930000 ldr r0, [r3] ad8: e5902004 ldr r2, [r0, #4] base.s.ptr = freep = prevp = &base; base.s.size = 0; } for(p = prevp->s.ptr; ; prevp = p, p = p->s.ptr){ if(p->s.size >= nunits){ adc: e1520004 cmp r2, r4 ae0: 2a00001b bcs b54 morecore(uint nu) { char *p; Header *hp; if(nu < 4096) ae4: e59f80ac ldr r8, [pc, #172] ; b98 p->s.size -= nunits; p += p->s.size; p->s.size = nunits; } freep = prevp; return (void*)(p + 1); ae8: e1a07184 lsl r7, r4, #3 aec: ea000003 b b00 nunits = (nbytes + sizeof(Header) - 1)/sizeof(Header) + 1; if((prevp = freep) == 0){ base.s.ptr = freep = prevp = &base; base.s.size = 0; } for(p = prevp->s.ptr; ; prevp = p, p = p->s.ptr){ af0: e5930000 ldr r0, [r3] if(p->s.size >= nunits){ af4: e5902004 ldr r2, [r0, #4] af8: e1540002 cmp r4, r2 afc: 9a000014 bls b54 p->s.size = nunits; } freep = prevp; return (void*)(p + 1); } if(p == freep) b00: e5952000 ldr r2, [r5] b04: e1a03000 mov r3, r0 b08: e1500002 cmp r0, r2 b0c: 1afffff7 bne af0 morecore(uint nu) { char *p; Header *hp; if(nu < 4096) b10: e1540008 cmp r4, r8 nu = 4096; p = sbrk(nu * sizeof(Header)); b14: 81a00007 movhi r0, r7 b18: 93a00902 movls r0, #32768 ; 0x8000 morecore(uint nu) { char *p; Header *hp; if(nu < 4096) b1c: 81a06004 movhi r6, r4 b20: 93a06a01 movls r6, #4096 ; 0x1000 nu = 4096; p = sbrk(nu * sizeof(Header)); b24: ebfffeec bl 6dc b28: e1a03000 mov r3, r0 if(p == (char*)-1) b2c: e3730001 cmn r3, #1 return 0; hp = (Header*)p; hp->s.size = nu; free((void*)(hp + 1)); b30: e2800008 add r0, r0, #8 Header *hp; if(nu < 4096) nu = 4096; p = sbrk(nu * sizeof(Header)); if(p == (char*)-1) b34: 0a000010 beq b7c return 0; hp = (Header*)p; hp->s.size = nu; b38: e5836004 str r6, [r3, #4] free((void*)(hp + 1)); b3c: ebffffb2 bl a0c return freep; b40: e5953000 ldr r3, [r5] } freep = prevp; return (void*)(p + 1); } if(p == freep) if((p = morecore(nunits)) == 0) b44: e3530000 cmp r3, #0 b48: 1affffe8 bne af0 return 0; b4c: e1a00003 mov r0, r3 } } b50: e8bd89f8 pop {r3, r4, r5, r6, r7, r8, fp, pc} base.s.ptr = freep = prevp = &base; base.s.size = 0; } for(p = prevp->s.ptr; ; prevp = p, p = p->s.ptr){ if(p->s.size >= nunits){ if(p->s.size == nunits) b54: e1540002 cmp r4, r2 prevp->s.ptr = p->s.ptr; else { p->s.size -= nunits; b58: 10642002 rsbne r2, r4, r2 b5c: 15802004 strne r2, [r0, #4] base.s.size = 0; } for(p = prevp->s.ptr; ; prevp = p, p = p->s.ptr){ if(p->s.size >= nunits){ if(p->s.size == nunits) prevp->s.ptr = p->s.ptr; b60: 05902000 ldreq r2, [r0] else { p->s.size -= nunits; p += p->s.size; b64: 10800182 addne r0, r0, r2, lsl #3 base.s.size = 0; } for(p = prevp->s.ptr; ; prevp = p, p = p->s.ptr){ if(p->s.size >= nunits){ if(p->s.size == nunits) prevp->s.ptr = p->s.ptr; b68: 05832000 streq r2, [r3] else { p->s.size -= nunits; p += p->s.size; p->s.size = nunits; b6c: 15804004 strne r4, [r0, #4] } freep = prevp; b70: e5853000 str r3, [r5] return (void*)(p + 1); b74: e2800008 add r0, r0, #8 b78: e8bd89f8 pop {r3, r4, r5, r6, r7, r8, fp, pc} } if(p == freep) if((p = morecore(nunits)) == 0) return 0; b7c: e3a00000 mov r0, #0 b80: e8bd89f8 pop {r3, r4, r5, r6, r7, r8, fp, pc} Header *p, *prevp; uint nunits; nunits = (nbytes + sizeof(Header) - 1)/sizeof(Header) + 1; if((prevp = freep) == 0){ base.s.ptr = freep = prevp = &base; b84: e2850004 add r0, r5, #4 b88: e5850000 str r0, [r5] base.s.size = 0; b8c: e9850009 stmib r5, {r0, r3} b90: eaffffd3 b ae4 b94: 00000be4 .word 0x00000be4 b98: 00000fff .word 0x00000fff