1 /* -------------------------------------------- 2 demo.s: recursive insert at tail of list 3 -------------------------------------------- */ 4 .global main, Stop, CodeEnd, DataStart, DataEnd 5 .global head, ptr, Insert 6 7 main: 8 // head = Insert(head, ptr) 9 // pass ptr 10 0000 000000E3 movw r0, #:lower16:ptr 11 0004 000040E3 movt r0, #:upper16:ptr 12 0008 000090E5 ldr r0, [r0] //r0 = ptr 13 000c 04002DE5 push {r0} 14 15 // pass head 16 0010 000000E3 movw r0, #:lower16:head 17 0014 000040E3 movt r0, #:upper16:head 18 0018 000090E5 ldr r0, [r0] //r0 = head 19 001c 04002DE5 push {r0} 20 21 0020 FEFFFFEB bl Insert 22 0024 08D08DE2 add sp, sp, #8 23 24 0028 000000E3 movw r0, #:lower16:head 25 002c 000040E3 movt r0, #:upper16:head 26 0030 00A080E5 str r10, [r0] // head = Insert(head, ptr) 27 28 Stop: 29 0034 0000A0E1 nop 30 31 // Return value in r10 32 Insert: 33 // Prelude 34 0038 04E02DE5 push {lr} 35 003c 04B02DE5 push {fp} 36 0040 0DB0A0E1 mov fp, sp 37 0044 00D04DE2 sub sp, sp, #0 38 39 //Body 40 0048 08009BE5 ldr r0, [fp, #8] 41 004c 000050E3 cmp r0, #0 42 0050 0400001A bne else 43 44 0054 0000A0E3 mov r0, #0 //r0=null 45 0058 0C109BE5 ldr r1, [fp, #12] 46 005c 040081E5 str r0, [r1, #4] // e.next = null 47 48 0060 0CA09BE5 ldr r10, [fp, #12] 49 0064 090000EA b postlude 50 51 else: 52 // call insert(head.next, e) 53 0068 0C009BE5 ldr r0, [fp,#12] 54 006c 04002DE5 push {r0} 55 56 0070 08009BE5 ldr r0, [fp,#8] 57 0074 040090E5 ldr r0, [r0, #4] 58 0078 04002DE5 push {r0} 59 60 007c FEFFFFEB bl Insert 61 0080 08D08DE2 add sp, sp, #8 62 63 0084 08009BE5 ldr r0, [fp, #8] // r0 = head 64 0088 04A080E5 str r10,[r0, #4] // head.next 65 66 67 008c 08A09BE5 ldr r10, [fp, #8] // r10 = head 68 69 // Postlude 70 postlude: 71 0090 0BD0A0E1 mov sp, fp 72 0094 04B09DE4 pop {fp} 73 0098 04F09DE4 pop {pc} 74 75 CodeEnd: 76 009c 0000A0E1 nop 77 78 79 /* *********************************************** 80 Prepared variables (head, ptr, a linked list) 81 *********************************************** */ 82 83 .data 84 DataStart: 85 86 0000 08000000 head: .4byte p0 // head = address of first list elem 87 // head->[11]->[22]->[33]->[44]->[55] 88 89 0004 30000000 ptr: .4byte p9 // ptr points to list elem to insert 90 91 // list structure is: [int value, next] 92 0008 0B000000 p0: .4byte 11, p3 // p0 contains [11, p3] 92 20000000 93 0010 21000000 p1: .4byte 33, p2 // p1 contains [33, p2] 93 18000000 94 0018 2C000000 p2: .4byte 44, p4 // p2 contains [44, p4] 94 28000000 95 0020 16000000 p3: .4byte 22, p1 // p3 contains [22, p1] 95 10000000 96 0028 37000000 p4: .4byte 55, 0 // p4 contains [55, 0] 96 00000000 97 98 0030 63000000 p9: .4byte 99, 0 // p9 contains [99, 0] 98 00000000 99 100 DataEnd: 101 .end DEFINED SYMBOLS /home/cs255001/cs255/demo/9-list-recursion/demo.s:7 .text:0000000000000000 main /home/cs255001/cs255/demo/9-list-recursion/demo.s:28 .text:0000000000000034 Stop /home/cs255001/cs255/demo/9-list-recursion/demo.s:75 .text:000000000000009c CodeEnd /home/cs255001/cs255/demo/9-list-recursion/demo.s:84 .data:0000000000000000 DataStart /home/cs255001/cs255/demo/9-list-recursion/demo.s:100 .data:0000000000000038 DataEnd /home/cs255001/cs255/demo/9-list-recursion/demo.s:86 .data:0000000000000000 head /home/cs255001/cs255/demo/9-list-recursion/demo.s:89 .data:0000000000000004 ptr /home/cs255001/cs255/demo/9-list-recursion/demo.s:32 .text:0000000000000038 Insert /home/cs255001/cs255/demo/9-list-recursion/demo.s:10 .text:0000000000000000 $a /home/cs255001/cs255/demo/9-list-recursion/demo.s:51 .text:0000000000000068 else /home/cs255001/cs255/demo/9-list-recursion/demo.s:70 .text:0000000000000090 postlude /home/cs255001/cs255/demo/9-list-recursion/demo.s:92 .data:0000000000000008 p0 /home/cs255001/cs255/demo/9-list-recursion/demo.s:98 .data:0000000000000030 p9 /home/cs255001/cs255/demo/9-list-recursion/demo.s:95 .data:0000000000000020 p3 /home/cs255001/cs255/demo/9-list-recursion/demo.s:93 .data:0000000000000010 p1 /home/cs255001/cs255/demo/9-list-recursion/demo.s:94 .data:0000000000000018 p2 /home/cs255001/cs255/demo/9-list-recursion/demo.s:96 .data:0000000000000028 p4 NO UNDEFINED SYMBOLS 1 2 .global malloc, print 3 .global stdout_start, stdout_end 4 5 // ********************************************** 6 // malloc: simulate memory allocate 7 // 8 // This function will NOT change ANY registers 9 // (I.e.: will preserve ALL registers) 10 // ********************************************** 11 malloc: 12 0000 0E002DE9 push {r1, r2, r3} // Save scratch registers 13 14 0004 001000E3 movw r1, #:lower16:maddr 15 0008 001040E3 movt r1, #:upper16:maddr // r1 = &maddr 16 000c 003091E5 ldr r3, [r1] // r3 = maddr 17 18 // -------------------------------------- 19 // Make new maddr (divisible by 8) 20 // -------------------------------------- 21 22 0010 002083E0 add r2, r3, r0 // New maddr 23 0014 082082E2 add r2, r2, #8 // Making sure it increase 24 25 0018 0700A0E3 mov r0, #0x7 // r0 = 0000..00111 26 001c 0000E0E1 mvn r0, r0 // r0 = 1111..11000 27 0020 002002E0 and r2, r2, r0 // Knock off the last 3 bits 28 0024 002081E5 str r2, [r1] // Update maddr 29 30 31 // -------------------------------------- 32 // Return to caller 33 // -------------------------------------- 34 0028 0300A0E1 mov r0, r3 // Return maddr value in r0 35 002c 0E00BDE8 pop {r1, r2, r3} // Restore scratch registers 36 0030 0EF0A0E1 mov pc, lr // Return 37 38 0034 00000400 maddr: .word 0x40000 // Start address of the heap 39 40 41 // ******************************************************************* 42 // print: simulate print output in Egtapi 43 // 44 // input: r0 = address of string 45 // r1 = # characters to write 46 // 47 // Egtapi will show ASCII data stored starting at stdout_start 48 // until stdout_end in its output area 49 // 50 // This function will NOT change ANY registers 51 // (I.e.: will preserve ALL registers) 52 // ******************************************************************* 53 print: 54 0038 1C002DE9 push {r2, r3, r4} // Save scratch registers 55 56 003c 002000E3 movw r2, #:lower16:stdout_end 57 0040 002040E3 movt r2, #:upper16:stdout_end // r2 = &stdout_end 58 0044 002092E5 ldr r2, [r2] // r2 = stdout_end 59 60 0048 0130A0E1 mov r3, r1 // r3 = # char to copy 61 62 printLoop: 63 004c 000053E3 cmp r3, #0 64 0050 0500000A beq printDone 65 66 0054 0040D0E5 ldrb r4, [r0] // Get next char 67 0058 0040C2E5 strb r4, [r2] // Write next char 68 69 005c 010080E2 add r0, r0, #1 70 0060 012082E2 add r2, r2, #1 71 72 0064 013043E2 sub r3, r3, #1 73 74 0068 F7FFFFEA b printLoop 75 76 printDone: 77 006c 2040A0E3 mov r4, #32 // Space 78 0070 0040C2E5 strb r4, [r2] 79 0074 012082E2 add r2, r2, #1 80 81 0078 003000E3 movw r3, #:lower16:stdout_end 82 007c 003040E3 movt r3, #:upper16:stdout_end // r2 = &stdout_end 83 0080 002083E5 str r2, [r3] 84 85 0084 1C00BDE8 pop {r2, r3, r4} // Restore scratch registers 86 0088 0EF0A0E1 mov pc, lr // Return 87 88 89 90 91 008c 00000500 stdout_start: .word 0x50000 // This value remains unchanged 92 0090 00000500 stdout_end: .word 0x50000 93 94 95 .end DEFINED SYMBOLS /home/egtapi/lib/cs255lib.s:11 .text:0000000000000000 malloc /home/egtapi/lib/cs255lib.s:53 .text:0000000000000038 print /home/egtapi/lib/cs255lib.s:91 .text:000000000000008c stdout_start /home/egtapi/lib/cs255lib.s:92 .text:0000000000000090 stdout_end /home/egtapi/lib/cs255lib.s:12 .text:0000000000000000 $a /home/egtapi/lib/cs255lib.s:38 .text:0000000000000034 maddr /home/egtapi/lib/cs255lib.s:38 .text:0000000000000034 $d /home/egtapi/lib/cs255lib.s:54 .text:0000000000000038 $a /home/egtapi/lib/cs255lib.s:62 .text:000000000000004c printLoop /home/egtapi/lib/cs255lib.s:76 .text:000000000000006c printDone /home/egtapi/lib/cs255lib.s:91 .text:000000000000008c $d NO UNDEFINED SYMBOLS