Cコンパイラ開発顛末記 小窓次郎 | 組み込み業界独り言からCコンパイラ(C3PO)をダウンロードして、TVボーイでMC6847を表示するプログラムを開発して行きます。
VRAM($1000-$17FF)、ROM($F000-$FFFF)の想定で書いていきます。
hello.cint memset(p, x, y)
char *p;
char x;
int y;
{
int i;
for (i=0; i<y; i++,p++) {
*p=x;
}
return 0;
}
int main()
{
char *p;
char *q;
p="HELLO WORLD";
q=0x2000;
*q=0x20;
memset(0x1000, ' ', 0x800);
for (q=0x1000; *p != 0; q++, p++) {
*q = *p;
}
return 0;
}
MS-DOSで開発します。
>msdos C3PO.EXE HELLO >notepad hello.src
hello.srcを編集してhello.txtで保存します。ＤＯＳ用８ビットＣＰＵクロスアセンブラでSレコード形式を作成します。
>msdos X6801.EXE hello 6801 Cross Assembler Version 3.12 Copyright(C) Arcpit Co.,LTD.1990. All rights reserved. Object Filename [HELLO.S] : Source Listting [NUL.LST] : Cross Reference [NUL.CRF] : Symbol Table [NUL.MAP] : ^L 2020- 6- 7 6801 Assembler Page 1 File:HELLO.TXT 1 ; INCLUDE 630X.LIB 2 ; 3 ;***** C3PO for 6301/3 version 3.06c MSDOS ***** Nishiy 4 ; *** Copyright (c) S.Nishiyama Mar 14 1992 5 ;*** 1 int memset(p, x, y) 6 ;*** 2 char *p; 7 ;*** 3 char x; 8 ;*** 4 int y; 9 ;*** 5 { 10 ;*** 6 int i; 11 ;*** 7 for (i=0; i<y; i++,p++) { 12 ; CSEG 13 ; GLOBAL _memset 14 F000 ORG $F000 15 00FF STACK EQU $FF 16 F000 8E00FF START LDS #STACK 17 F003 2035 BRA _main 18 F005 _memset: 19 F005 3C PSHX 20 F006 30 TSX 21 F007 37 PSHB 22 F008 36 PSHA 23 F009 34 DES 24 F00A 34 DES 25 F00B 4F CLRA 26 F00C 5F CLRB 27 F00D 30 TSX 28 F00E ED00 STD 0,X 29 F010 L3: 30 F010 EC08 LDD 8,X 31 F012 A300 SUBD 0,X 32 F014 2F19 BLE L2 33 ;*** 8 *p=x; 34 F016 4F CLRA 35 F017 E605 LDAB 5,X 36 F019 EE02 LDX 2,X 37 F01B E700 STAB 0,X 38 F01D 30 TSX 39 ;*** 9 } 40 ;*** 10 return 0; 41 F01E L4: 42 F01E EC00 LDD 0,X 43 F020 C30001 ADDD #1 44 F023 ED00 STD 0,X 45 F025 EC02 LDD 2,X 46 F027 C30001 ADDD #1 47 F02A ED02 STD 2,X 48 F02C 7EF010 JMP L3 49 F02F L2: 50 F02F 4F CLRA 51 F030 5F CLRB 52 ;*** 11 } 53 F031 7EF034 JMP L1 54 F034 L1: 55 F034 31 INS 56 F035 31 INS 57 F036 31 INS 58 F037 31 INS ^L 2020- 6- 7 6801 Assembler Page 2 File:HELLO.TXT 59 F038 38 PULX 60 F039 39 RTS 61 ;** Local value mapping information 62 ;** i EQU 0 63 ;** y EQU 8 64 ;** x EQU 5 65 ;** p EQU 2 66 ;* Function67 ;* Executive step count 8 68 ;* Used stack size ===6 Byte=== ^L 2020- 6- 7 6801 Assembler Page 3 File:HELLO.TXT 70 ;*** 12 71 ;*** 13 int main() 72 ;*** 14 { 73 ;*** 15 char *p; 74 ;*** 16 char *q; 75 ;*** 17 p="HELLO WORLD"; 76 ; GLOBAL _main 77 F03A _main: 78 F03A 3C PSHX 79 F03B 30 TSX 80 F03C 34 DES 81 F03D 34 DES 82 F03E 34 DES 83 F03F 34 DES 84 F040 3C PSHX 85 F041 30 TSX 86 F042 CCF093 LDD #S0 87 F045 ED04 STD 4,X 88 ;*** 18 q=0x2000; 89 F047 CC2000 LDD #8192 90 F04A ED02 STD 2,X 91 ;*** 19 *q=0x20; 92 F04C EE02 LDX 2,X 93 F04E C620 LDAB #$20 94 F050 E700 STAB 0,X 95 F052 30 TSX 96 ;*** 20 memset(0x1000, ' ', 0x800); 97 F053 CC0800 LDD #2048 98 F056 37 PSHB 99 F057 36 PSHA 100 F058 CE0020 LDX #32 101 F05B 05 ASLD 102 F05C BDF005 JSR _memset 103 F05F 31 INS 104 F060 31 INS 105 F061 30 TSX 106 ;*** 21 for (q=0x1000; *p != 0; q++, p+ 107 F062 CC1000 LDD #4096 108 F065 ED02 STD 2,X 109 F067 L7: 110 F067 EE04 LDX 4,X 111 F069 4F CLRA 112 F06A E600 LDAB 0,X 113 F06C 30 TSX 114 F06D 271B BEQ L6 115 ;*** 22 *q = *p; 116 F06F EE04 LDX 4,X 117 F071 E600 LDAB 0,X 118 F073 30 TSX 119 F074 EE02 LDX 2,X 120 F076 E700 STAB 0,X 121 F078 30 TSX 122 ;*** 23 } 123 ;*** 24 return 0; 124 F079 L8: 125 F079 EC02 LDD 2,X 126 F07B C30001 ADDD #1 127 F07E ED02 STD 2,X ^L 2020- 6- 7 6801 Assembler Page 4 File:HELLO.TXT 128 F080 EC04 LDD 4,X 129 F082 C30001 ADDD #1 130 F085 ED04 STD 4,X 131 F087 7EF067 JMP L7 132 F08A 20FE L6: BRA L6 133 ;*** 25 } 134 F08C 7EF08F JMP L5 135 F08F L5: 136 F08F 38 PULX 137 F090 35 TXS 138 F091 38 PULX 139 F092 39 RTS 140 ;** Local value mapping information 141 ;** q EQU 2 142 ;** p EQU 4 143 ;* Function 144 ;* Executive step count 12 145 ;* Used stack size ===14 Byte=== ^L 2020- 6- 7 6801 Assembler Page 5 File:HELLO.TXT 147 ;*** 26 148 F093 S0: 149 F093 48454C4C4F20 FCB 72,69,76,76,79,32,87,79 574F 150 F09B 524C4400 FCB 82,76,68,0 151 ;* Direct page size 0 152 ;* Global segment size 0 153 ;* Character size 12 154 ;* Executive step count 20 155 ;* Error count 0 156 FFFE ORG $FFFE 157 FFFE F000 FDB START 158 0000 END ^L 2020- 6- 7 6801 Assembler Page 6 File:HELLO.TXT SYMBOL TABLE: L1 F034 L2 F02F L3 F010 L4 F01E L5 F08F L6 F08A L7 F067 L8 F079 S0 F093 STACK 00FF START F000 _main F03A _memset F005 ^L 2020- 6- 7 6801 Assembler Page 7 File:HELLO.TXT 0 Error(s) detected. LINES : 158 LABELS : 13 LAST PROGRAM ADDRESS : $FFFD LAST DATA ADDRESS : $0000
SRecord 1.64でhello.sをhello.binに変換します。
>srec_cat hello.S -offset -0xF000 -o hello.bin -binary
