diff options
Diffstat (limited to 'tasm/src')
| -rw-r--r-- | tasm/src/assembler.c | 216 | ||||
| -rw-r--r-- | tasm/src/bits.c | 22 | ||||
| -rw-r--r-- | tasm/src/parser.y | 26 |
3 files changed, 232 insertions, 32 deletions
diff --git a/tasm/src/assembler.c b/tasm/src/assembler.c index c0c05be..9f6dc95 100644 --- a/tasm/src/assembler.c +++ b/tasm/src/assembler.c @@ -9,10 +9,29 @@ #include <stdio.h> #include <errno.h> +struct asm_symbol { + const char *name; + size_t offset; +}; + +struct asm_reloc { + enum asm_reloc_kind kind; + const char *sym; + size_t offset; +}; + struct asm_ctx { size_t size; size_t idx; tri_t *buf; + + size_t sym_max; + size_t sym_count; + struct asm_symbol *syms; + + size_t reloc_max; + size_t reloc_count; + struct asm_reloc *relocs; }; static void emit(struct asm_ctx *ctx, tri_t i) @@ -259,11 +278,174 @@ int process_file(struct asm_ctx *ctx, const char *file) return res; } +static struct asm_ctx *asm_ctx_create() +{ + struct asm_ctx *ctx = malloc(sizeof(struct asm_ctx)); + /* code buffer */ + ctx->size = 1; + ctx->buf = malloc(sizeof(tri_t)); + ctx->idx = 0; + + /* relocations */ + ctx->reloc_max = 1; + ctx->relocs = malloc(sizeof(struct asm_reloc)); + ctx->reloc_count = 0; + + /* symbols */ + ctx->sym_max = 1; + ctx->syms = malloc(sizeof(struct asm_reloc)); + ctx->sym_count = 0; + + return ctx; +} + +static void asm_ctx_relocs_destroy(struct asm_ctx *ctx) +{ + for (size_t i = 0; i < ctx->reloc_count; ++i) { + free((void *)ctx->relocs[i].sym); + } + + free(ctx->relocs); +} + +static void asm_ctx_syms_destroy(struct asm_ctx *ctx) +{ + for (size_t i = 0; i < ctx->sym_count; ++i) { + free((void *)ctx->syms[i].name); + } + + free(ctx->syms); +} + +static void asm_ctx_destroy(struct asm_ctx *ctx) +{ + free(ctx->buf); + asm_ctx_relocs_destroy(ctx); + asm_ctx_syms_destroy(ctx); + free(ctx); +} + +static void fix_reloc_la(struct asm_ctx *ctx, size_t ro, size_t so) +{ + tri_t t = tri_from(so); + /* 9 lowest */ + tri_t lo = tri_mask(t, 9); + /* 18 highest */ + tri_t hi = tri_mask(tri_sr(t, 9), 18); + + /* lui, assume zero-initialized immediate */ + tri_t lui = ctx->buf[ro]; + assert(parse_opcode(lui) == OPCODE_LUI); + tri_t rd, imm; + parse_u(lui, &rd, &imm); + assert(imm == 0); + ctx->buf[ro] = build_u(OPCODE_LUI, rd, hi); + + /* addi */ + tri_t addi = ctx->buf[ro + 1]; + assert(parse_opcode(addi) == OPCODE_OP_IMM); + tri_t fn0, rs1; + parse_i(addi, &rd, &fn0, &rs1, &imm); + assert(fn0 == OP_IMM_ADDI); + assert(imm == 0); + ctx->buf[ro + 1] = build_i(OPCODE_OP_IMM, rd, fn0, rs1, lo); +} + +static void fix_reloc_b(struct asm_ctx *ctx, size_t ro, size_t so) +{ + int64_t off = so - ctx->idx; + tri_t t = tri_from(off); + if (tri_mask(t, 9) != t) { + /* should really be line based rather than offset, but good + * enough for now */ + fprintf(stderr, "branch offset at %llu too large\n", + (unsigned long long)ro); + abort(); + } + + /* low five */ + tri_t lo = tri_mask(t, 5); + /* high four */ + tri_t hi = tri_mask(tri_sr(t, 5), 4); + + tri_t b = ctx->buf[ro]; + assert(parse_opcode(b) == OPCODE_BRANCH); + + tri_t imm4, fn0, rs1, rs2, imm5; + parse_s(b, &imm4, &fn0, &rs1, &rs2, &imm5); + assert(imm4 == 0 && imm5 == 0); + + ctx->buf[ro] = build_s(OPCODE_BRANCH, hi, fn0, rs1, rs2, lo); +} + +static void fix_reloc_j(struct asm_ctx *ctx, size_t ro, size_t so) +{ + int64_t off = so - ctx->idx; + tri_t t = tri_from(off); + if (tri_mask(t, 18) != t) { + fprintf(stderr, "jump offset at %llu too large\n", + (unsigned long long)ro); + abort(); + } + + tri_t j = ctx->buf[ro]; + assert(parse_opcode(j) == OPCODE_JAL); + + tri_t rd, imm18; + parse_u(j, &rd, &imm18); + assert(imm18 == 0); + + ctx->buf[ro] = build_u(OPCODE_JAL, rd, t); +} + +static int try_fix_reloc(struct asm_ctx *ctx, struct asm_reloc r) +{ + /* ideally this would probably be a hashmap, but good enough for now */ + for (size_t i = 0; i < ctx->sym_count; ++i) { + struct asm_symbol s = ctx->syms[i]; + if (strcmp(s.name, r.sym) != 0) + continue; + + size_t ro = r.offset; + size_t so = s.offset; + /* matching */ + switch (r.kind) { + case RELOC_LA: fix_reloc_la(ctx, ro, so); break; + case RELOC_B: fix_reloc_b(ctx, ro, so); break; + case RELOC_J: fix_reloc_j(ctx, ro, so); break; + default: fprintf(stderr, "unimplemented reloc: %d\n", r.kind); + abort(); + } + return 0; + } + + /* we didn't find a symbol matching reloc */ + return 1; +} + +static int fix_relocs(struct asm_ctx *ctx) +{ + for (size_t i = 0; i < ctx->reloc_count; ++i) { + struct asm_reloc r = ctx->relocs[i]; + if (try_fix_reloc(ctx, r)) { + /* we were unable to fulfill this reloc, fail */ + fprintf(stderr, "unable to fulfill reloc for %s\n", r.sym); + return 1; + } + } + + return 0; +} + int assemble(const char *outfile, const char *infile) { /** @todo cleanup */ - struct asm_ctx ctx = {.size = 1, .buf = malloc(sizeof(tri_t)), .idx = 0}; - int ret = process_file(&ctx, infile); + struct asm_ctx *ctx = asm_ctx_create(); + int ret = process_file(ctx, infile); + if (ret) + return ret; + + ret = fix_relocs(ctx); if (ret) return ret; @@ -271,8 +453,8 @@ int assemble(const char *outfile, const char *infile) if (!f) return -1; - for (size_t i = 0; i < ctx.idx; ++i) { - tri_t t = ctx.buf[i]; + for (size_t i = 0; i < ctx->idx; ++i) { + tri_t t = ctx->buf[i]; /* output trytewise LE */ uint32_t t0 = tri_mask(t, 9); uint32_t t1 = tri_mask(tri_sr(t, 9), 9); @@ -289,7 +471,8 @@ int assemble(const char *outfile, const char *infile) } fclose(f); - free(ctx.buf); + asm_ctx_destroy(ctx); + return 0; } void check_shift(tri_t shmt) @@ -382,12 +565,29 @@ tri_t check_width(const char *width) return 0; } -void emit_reloc(struct asm_ctx *ctx, enum asm_reloc reloc, const char *name) +void emit_reloc(struct asm_ctx *ctx, enum asm_reloc_kind reloc, const char *name) { - /** @todo implement */ + if (ctx->reloc_count >= ctx->reloc_max) { + ctx->reloc_max *= 2; + ctx->relocs = realloc(ctx->relocs, ctx->reloc_max * sizeof(struct asm_reloc)); + } + + ctx->relocs[ctx->reloc_count++] = (struct asm_reloc){ + .kind = reloc, + .sym = strdup(name), + .offset = ctx->idx + }; } void emit_label(struct asm_ctx *ctx, const char *name) { - /** @todo implement */ + if (ctx->sym_count >= ctx->sym_max) { + ctx->sym_max *= 2; + ctx->syms = realloc(ctx->syms, ctx->sym_max * sizeof(struct asm_symbol)); + } + + ctx->syms[ctx->sym_count++] = (struct asm_symbol){ + .name = strdup(name), + .offset = ctx->idx + }; } diff --git a/tasm/src/bits.c b/tasm/src/bits.c index 6397e2f..7a54632 100644 --- a/tasm/src/bits.c +++ b/tasm/src/bits.c @@ -36,10 +36,10 @@ tri_t build_i(tri_t opcode, tri_t rd, tri_t fn0, tri_t rs1, tri_t imm9) void parse_i(tri_t i, tri_t *rd, tri_t *fn0, tri_t *rs1, tri_t *imm9) { - *rd = tri_mask(tri_sl(i, 5), 4); - *fn0 = tri_mask(tri_sl(i, 9), 5); - *rs1 = tri_mask(tri_sl(i, 14), 4); - *imm9 = tri_mask(tri_sl(i, 18), 9); + *rd = tri_mask(tri_sr(i, 5), 4); + *fn0 = tri_mask(tri_sr(i, 9), 5); + *rs1 = tri_mask(tri_sr(i, 14), 4); + *imm9 = tri_mask(tri_sr(i, 18), 9); } tri_t build_s(tri_t opcode, tri_t imm4, tri_t fn0, tri_t rs1, tri_t rs2, tri_t imm5) @@ -54,11 +54,11 @@ tri_t build_s(tri_t opcode, tri_t imm4, tri_t fn0, tri_t rs1, tri_t rs2, tri_t i void parse_s(tri_t i, tri_t *imm4, tri_t *fn0, tri_t *rs1, tri_t *rs2, tri_t *imm5) { - *imm4 = tri_mask(tri_sl(i, 5), 4); - *fn0 = tri_mask(tri_sl(i, 9), 5); - *rs1 = tri_mask(tri_sl(i, 14), 4); - *rs2 = tri_mask(tri_sl(i, 18), 4); - *imm5 = tri_mask(tri_sl(i, 22), 5); + *imm4 = tri_mask(tri_sr(i, 5), 4); + *fn0 = tri_mask(tri_sr(i, 9), 5); + *rs1 = tri_mask(tri_sr(i, 14), 4); + *rs2 = tri_mask(tri_sr(i, 18), 4); + *imm5 = tri_mask(tri_sr(i, 22), 5); } tri_t build_u(tri_t opcode, tri_t rd, tri_t imm18) @@ -70,6 +70,6 @@ tri_t build_u(tri_t opcode, tri_t rd, tri_t imm18) void parse_u(tri_t i, tri_t *rd, tri_t *imm18) { - *rd = tri_mask(tri_sl(i, 5), 4); - *imm18 = tri_mask(tri_sl(i, 9), 18); + *rd = tri_mask(tri_sr(i, 5), 4); + *imm18 = tri_mask(tri_sr(i, 9), 18); } diff --git a/tasm/src/parser.y b/tasm/src/parser.y index ef8d3df..559cbba 100644 --- a/tasm/src/parser.y +++ b/tasm/src/parser.y @@ -289,27 +289,28 @@ i {emit_u(ctx, OPCODE_AUIPC, $2, $4);} | jal gpr "," addr - {emit_u(ctx, OPCODE_JAL, $2, 0); - emit_reloc(ctx, RELOC_J, $4);} + {emit_reloc(ctx, RELOC_J, $4); + emit_u(ctx, OPCODE_JAL, $2, 0);} | jalr gpr "," gpr "," imm {emit_i(ctx, OPCODE_JALR, $2, 0, $4, $6);} | beq gpr "," gpr "," addr - {emit_s(ctx, OPCODE_BRANCH, BRANCH_BEQ, $2, $4, 0); - emit_reloc(ctx, RELOC_B, $6);} + {emit_reloc(ctx, RELOC_B, $6); + emit_s(ctx, OPCODE_BRANCH, BRANCH_BEQ, $2, $4, 0);} | bne gpr "," gpr "," addr - {emit_s(ctx, OPCODE_BRANCH, BRANCH_BNE, $2, $4, 0); - emit_reloc(ctx, RELOC_B, $6);} + {emit_reloc(ctx, RELOC_B, $6); + emit_s(ctx, OPCODE_BRANCH, BRANCH_BNE, $2, $4, 0);} | blt gpr "," gpr "," addr - {emit_s(ctx, OPCODE_BRANCH, BRANCH_BLT, $2, $4, 0); - emit_reloc(ctx, RELOC_B, $6);} + {emit_reloc(ctx, RELOC_B, $6); + emit_s(ctx, OPCODE_BRANCH, BRANCH_BLT, $2, $4, 0); + } | bge gpr "," gpr "," addr - {emit_s(ctx, OPCODE_BRANCH, BRANCH_BGE, $2, $4, 0); - emit_reloc(ctx, RELOC_B, $6);} + {emit_reloc(ctx, RELOC_B, $6); + emit_s(ctx, OPCODE_BRANCH, BRANCH_BGE, $2, $4, 0);} | ld width "," gpr "," imm "(" gpr ")" {emit_i(ctx, OPCODE_LOAD, check_width($2), $4, $8, $6);} @@ -340,9 +341,8 @@ i {emit_i(ctx, OPCODE_OP_IMM, X0_NUM, OP_IMM_ADDI, X0_NUM, 0);} | la gpr "," addr - {emit_u(ctx, OPCODE_LUI, $2, 0); - /* important that the reloc is in the middle here */ - emit_reloc(ctx, RELOC_LA, $4); + {emit_reloc(ctx, RELOC_LA, $4); + emit_u(ctx, OPCODE_LUI, $2, 0); emit_i(ctx, OPCODE_OP_IMM, $2, OP_IMM_ADDI, $2, 0);} | li gpr "," imm |