1 2 .global main, Stop, CodeEnd, DataStart, DataEnd 3 4 .global head 5 6 main: 7 // Get the RHS first 8 0000 E70300E3 mov r0, #999 // r0 = 999 9 10 // Store r0 into LHS 11 0004 001000E3 movw r1, #:lower16:head 12 0008 001040E3 movt r1, #:upper16:head // r0 = addr(head) 13 000c 001091E5 ldr r1, [r1] // r0 = head 14 0010 081091E5 ldr r1, [r1, #8] // r0 = head.next 15 16 0014 B400C1E1 strh r0, [r1, #4] // head.next.value2 = r0 = 999 17 // = head.next.next.value3 18 Stop: 19 0018 0000A0E1 nop 20 CodeEnd: 21 22 23 /* ************************************************************** 24 Permanent variables 25 ************************************************************** */ 26 27 .data 28 .align 12 29 DataStart: 30 31 // list structure is: [int value1, short value2, short value3, next] 32 33 0000 4D010000 p0: .4byte 333 // Object [333,23,33,p2] 34 0004 17002100 .2byte 23, 33 35 0008 1C000000 .4byte p2 36 37 000c 00000000 .skip 4 // gap 38 39 0010 6F000000 p1: .4byte 111 // Object [111,21,31,p3] 40 0014 15001F00 .2byte 21, 31 41 0018 2C000000 .4byte p3 42 43 44 001c BC010000 p2: .4byte 444 // Object [444,24,34,p4] 45 0020 18002200 .2byte 24, 34 46 0024 3C000000 .4byte p4 47 48 0028 00000000 .skip 4 // gap 49 50 002c DE000000 p3: .4byte 222 // Object [222,22,32,p2] 51 0030 16002000 .2byte 22, 32 52 0034 00000000 .4byte p0 53 54 0038 00000000 .skip 4 // gap 55 56 003c 2B020000 p4: .4byte 555 // Object [555,25,35,null] 57 0040 19002300 .2byte 25, 35 58 0044 00000000 .4byte 0 59 60 0048 10000000 head: .word p1 // head contains the address of the first list elem 61 // head->[111,21,31]->[222,22,32]->[333,23,33]-> 62 // ->[444,24,34]->[555,25,35] 63 64 DataEnd: 65 .end DEFINED SYMBOLS /home/cs255001/cs255/demo/4-linked-list/list2a.s:6 .text:0000000000000000 main /home/cs255001/cs255/demo/4-linked-list/list2a.s:18 .text:0000000000000018 Stop /home/cs255001/cs255/demo/4-linked-list/list2a.s:20 .text:000000000000001c CodeEnd /home/cs255001/cs255/demo/4-linked-list/list2a.s:29 .data:0000000000000000 DataStart /home/cs255001/cs255/demo/4-linked-list/list2a.s:64 .data:000000000000004c DataEnd /home/cs255001/cs255/demo/4-linked-list/list2a.s:60 .data:0000000000000048 head /home/cs255001/cs255/demo/4-linked-list/list2a.s:8 .text:0000000000000000 $a /home/cs255001/cs255/demo/4-linked-list/list2a.s:28 .data:0000000000000000 $d /home/cs255001/cs255/demo/4-linked-list/list2a.s:33 .data:0000000000000000 p0 /home/cs255001/cs255/demo/4-linked-list/list2a.s:44 .data:000000000000001c p2 /home/cs255001/cs255/demo/4-linked-list/list2a.s:39 .data:0000000000000010 p1 /home/cs255001/cs255/demo/4-linked-list/list2a.s:50 .data:000000000000002c p3 /home/cs255001/cs255/demo/4-linked-list/list2a.s:56 .data:000000000000003c 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