uxn

Varvara Ordinator, written in ANSI C(SDL2)
git clone https://git.eamoncaddigan.net/uxn.git
Log | Files | Refs | README | LICENSE

commit ba2e7aefa16de2488ff1e45f00a80ba5c1b767b7
parent 099d1f08455ceffce3512e6a7655c0d3df70ffe4
Author: neauoire <aliceffekt@gmail.com>
Date:   Sat, 30 Jan 2021 14:25:48 -0800

*

Diffstat:
M.clang-format | 6+++---
MREADME.md | 41++++++++++++++++++++++++-----------------
Mexample.usm | 7+++++--
Muxn.c | 98+++++++++++++++++++++++++++++++++++++++++++++++++++----------------------------
Muxnasm.c | 128++++++++++++++++++++++++++++++++++++++++++++++++++++++++-----------------------
5 files changed, 186 insertions(+), 94 deletions(-)

diff --git a/.clang-format b/.clang-format @@ -1,11 +1,11 @@ AlignAfterOpenBracket: DontAlign AlignEscapedNewlines: DontAlign AlignOperands: DontAlign -AllowShortBlocksOnASingleLine: Empty +AllowShortBlocksOnASingleLine: Always AllowShortCaseLabelsOnASingleLine: true AllowShortEnumsOnASingleLine: true -AllowShortIfStatementsOnASingleLine: false -AllowShortLoopsOnASingleLine: false +AllowShortIfStatementsOnASingleLine: true +AllowShortLoopsOnASingleLine: true AlwaysBreakAfterDefinitionReturnType: TopLevel BinPackArguments: false BinPackParameters: false diff --git a/README.md b/README.md @@ -11,26 +11,23 @@ cc uxn.c -std=c89 -Os -DNDEBUG -g0 -s -Wall -Wno-unknown-pragmas -o uxn ## Assembly Syntax ``` -: starting a definition -& obtaining pointers -( stack comments -` inlining bytecodes -' strings -# numbers -$ characters -~ vector -[ 12 34 ] real values -< 12 34 > relative values -( 12 34 ) deadzone -``` +< comment > -``` -;add-two JSR ++01 < literal > + +[ 01 02 03 04 ] < block of literals > + +$01 < pointer8 > + +{ 01 02 03 04 } < block of pointer8 > -BRK +~ff0f < pointer16 > -:add-two - [ 2 ] ADD RTS +( ff00 ff01 ff02 ff03 ) < block of pointer16 > + +=const +ff + +:label ADD RTS ``` ## Design @@ -57,3 +54,12 @@ BRK ### Emulator - SDL Layer + + +## Refs + +https://code.9front.org/hg/plan9front/file/a7f9946e238f/sys/src/games/nes/cpu.c +http://www.w3group.de/stable_glossar.html +http://www.emulator101.com/6502-addressing-modes.html +http://forth.works/8f0c04f616b6c34496eb2141785b4454 +https://justinmeiners.github.io/lc3-vm/ +\ No newline at end of file diff --git a/example.usm b/example.usm @@ -1 +1,5 @@ -{ 25 26 27 28 } SWP POP DUP BRK -\ No newline at end of file +< comment > + +[3 1 2 3 ] pop dup swp ovr rot + +brk diff --git a/uxn.c b/uxn.c @@ -29,19 +29,23 @@ typedef struct { Uint8 address[STACK_DEPTH]; } Computer; +Computer cpu; + +#pragma mark - Helpers + void -setflag(Computer *cpu, char flag, int b) +setflag(char flag, int b) { if(b) - cpu->status |= flag; + cpu.status |= flag; else - cpu->status &= (~flag); + cpu.status &= (~flag); } int -getflag(Computer *cpu, char flag) +getflag(char flag) { - return cpu->status & flag; + return cpu.status & flag; } void @@ -57,30 +61,31 @@ echo(Uint8 *s, Uint8 len, char *name) printf("\n\n"); } +#pragma mark - Operations + void op_push(Uint8 *s, Uint8 *ptr, Uint8 v) { - s[*ptr] = v; - (*ptr) += 1; + s[(*ptr)++] = v; } -void +Uint8 op_pop(Uint8 *s, Uint8 *ptr) { - s[*ptr--] = 0x00; + return s[--*ptr]; } void -reset(Computer *cpu) +reset(void) { int i; - cpu->status = 0x00; - cpu->counter = 0x00; - cpu->mptr = 0x00; - cpu->sptr = 0x00; - cpu->literal = 0x00; + cpu.status = 0x00; + cpu.counter = 0x00; + cpu.mptr = 0x00; + cpu.sptr = 0x00; + cpu.literal = 0x00; for(i = 0; i < 256; i++) - cpu->stack[i] = 0x00; + cpu.stack[i] = 0x00; } int @@ -91,39 +96,63 @@ error(char *name) } void -load(Computer *cpu, FILE *f) +load(FILE *f) { - fread(cpu->memory, sizeof(cpu->memory), 1, f); + fread(cpu.memory, sizeof(cpu.memory), 1, f); } void -eval(Computer *cpu) +eval() { - Uint8 instr = cpu->memory[cpu->mptr++]; - - if(cpu->literal > 0) { - printf("push: %02x[%d](%d)\n", instr, cpu->literal, cpu->sptr); - op_push(cpu->stack, &cpu->sptr, instr); - cpu->literal--; + Uint8 instr = cpu.memory[cpu.mptr++]; + Uint8 a, b, c; + if(cpu.literal > 0) { + printf("push: %02x[%d](%d)\n", instr, cpu.literal, cpu.sptr); + op_push(cpu.stack, &cpu.sptr, instr); + cpu.literal--; return; } switch(instr) { - case 0x0: setflag(cpu, FLAG_HALT, 1); break; - case 0x1: cpu->literal += 4; break; + case 0x0: setflag(FLAG_HALT, 1); break; + case 0x1: cpu.literal += cpu.memory[cpu.mptr++]; break; + case 0x2: printf("??\n"); break; + case 0x3: /* pop */ + op_pop(cpu.stack, &cpu.sptr); + break; + case 0x4: /* dup */ + op_push(cpu.stack, &cpu.sptr, cpu.stack[cpu.sptr - 1]); + break; + case 0x5: /* swp */ + b = op_pop(cpu.stack, &cpu.sptr); + a = op_pop(cpu.stack, &cpu.sptr); + op_push(cpu.stack, &cpu.sptr, b); + op_push(cpu.stack, &cpu.sptr, a); + break; + case 0x6: /* ovr */ + op_push(cpu.stack, &cpu.sptr, cpu.stack[cpu.sptr - 2]); + break; + case 0x7: /* rot */ + c = op_pop(cpu.stack, &cpu.sptr); + b = op_pop(cpu.stack, &cpu.sptr); + a = op_pop(cpu.stack, &cpu.sptr); + op_push(cpu.stack, &cpu.sptr, b); + op_push(cpu.stack, &cpu.sptr, c); + op_push(cpu.stack, &cpu.sptr, a); + break; default: printf("Unknown instruction: #%02x\n", instr); } } void -run(Computer *cpu) +run(void) { int i; - while((cpu->status & FLAG_HALT) == 0) + while((cpu.status & FLAG_HALT) == 0) eval(cpu); /* debug */ - printf("ended @ %d | ", cpu->counter); + printf("ended @ %d | ", cpu.counter); for(i = 0; i < 4; i++) - printf("%d-", (cpu->status & (1 << i)) != 0); + printf("%d-", (cpu.status & (1 << i)) != 0); printf("\n\n"); } @@ -131,14 +160,13 @@ int main(int argc, char *argv[]) { FILE *f; - Computer cpu; if(argc < 2) return error("No input."); if(!(f = fopen(argv[1], "rb"))) return error("Missing input."); - reset(&cpu); - load(&cpu, f); - run(&cpu); + reset(); + load(f); + run(); /* print result */ echo(cpu.stack, 0x40, "stack"); echo(cpu.memory, 0x40, "memory"); diff --git a/uxnasm.c b/uxnasm.c @@ -16,43 +16,31 @@ WITH REGARD TO THIS SOFTWARE. typedef unsigned char Uint8; typedef struct { - int ptr; + int len; Uint8 data[PRGLEN]; } Program; +char labels[256][16]; + char opcodes[][4] = { "BRK", "LIT", + "---", + "POP", "DUP", - "DRP", "SWP", - "SLP", - "PSH", - "POP", /* --- */ + "OVR", + "ROT", + /* */ "JMP", "JSR", - "RST", - "BEQ", + "JEQ", + "RTS", "EQU", "NEQ", "LTH", - "GTH", /* --- */ - "---", - "---", - "---", - "---", - "---", - "---", - "---", - "---", /* --- */ - "---", - "---", - "---", - "---", - "---", - "---", - "---", - "---"}; + "GTH", + /* */}; Program p; @@ -79,6 +67,17 @@ suca(char *s) /* string to uppercase */ } int +sihx(char *s) +{ + int i = 0; + char c; + while((c = s[i++])) + if(!(c >= '0' && c <= '9') && !(c >= 'A' && c <= 'F')) + return 0; + return 1; +} + +int shex(char *s) /* string to num */ { int n = 0, i = 0; @@ -86,36 +85,90 @@ shex(char *s) /* string to num */ while((c = s[i++])) if(c >= '0' && c <= '9') n = n * 16 + (c - '0'); - else if(c >= 'a' && c <= 'f') - n = n * 16 + 10 + (c - 'a'); + else if(c >= 'A' && c <= 'F') + n = n * 16 + 10 + (c - 'A'); return n; } -#pragma mark - Helpers +#pragma mark - Parser + +void +addprg(Uint8 hex) +{ + p.data[p.len++] = hex; +} + +void +addlabel(char *id, Uint8 addr) +{ + printf("new label: %s=%02x\n", id, addr); +} + +void +addconst(char *id, Uint8 value) +{ + printf("new const: %s=%02x\n", id, value); +} Uint8 -getopcode(char *s) +findop(char *s) { int i; - if(s[0] == '{') /* TODO catch closing */ - return 0x01; for(i = 0; i < 16; ++i) - if(scmp(opcodes[i], suca(s))) + if(scmp(opcodes[i], s)) return i; - return 0xff; + return 0; +} + +int +comment(char *w, int *skip) +{ + if(w[0] == '>') { + *skip = 0; + return 1; + } + if(w[0] == '<') *skip = 1; + if(*skip) return 1; + return 0; } void pass1(FILE *f) { + int skip = 0; char word[64]; while(fscanf(f, "%s", word) == 1) { - int op = getopcode(word); - if(word[0] == '}') + if(comment(word, &skip)) continue; - if(op == 0xff) - op = shex(word); - p.data[p.ptr++] = op; + } + rewind(f); +} + +void +pass2(FILE *f) +{ + int skip = 0; + char word[64]; + while(fscanf(f, "%s", word) == 1) { + Uint8 op; + suca(word); + if(comment(word, &skip)) continue; + if(word[0] == ']') continue; + if(word[0] == '+') { + addprg(0x01); + addprg(1); + addprg(shex(word + 1)); + } else if(word[0] == '[') { + addprg(0x01); + addprg(shex(word + 1)); + } else if((op = findop(word))) + addprg(op); + else if(sihx(word)) + addprg(shex(word)); + else if(scmp(word, "BRK")) + addprg(0x00); + else + printf("unknown: %s\n", word); } } @@ -135,6 +188,7 @@ main(int argc, char *argv[]) if(!(f = fopen(argv[1], "r"))) return error("Missing input."); pass1(f); + pass2(f); fwrite(p.data, sizeof(p.data), 1, fopen(argv[2], "wb")); fclose(f); return 0;