diff options
Diffstat (limited to 'triscv/src/cpu.c')
| -rw-r--r-- | triscv/src/cpu.c | 112 |
1 files changed, 21 insertions, 91 deletions
diff --git a/triscv/src/cpu.c b/triscv/src/cpu.c index 54e892c..fc6b721 100644 --- a/triscv/src/cpu.c +++ b/triscv/src/cpu.c @@ -1,6 +1,7 @@ #include <triscv/cpu.h> #include <triscv/mmu.h> #include <triscv/csr.h> +#include <bits.h> struct cpu { vm_t pc; @@ -95,72 +96,15 @@ void cpu_destroy(struct cpu *cpu) free(cpu); } -static tri_t get_rd(tri_t i) -{ - i = tri_sr(i, 5); - return tri_mask(i, 4); -} - -static tri_t get_rs1(tri_t i) -{ - i = tri_sr(i, 14); - return tri_mask(i, 4); -} - -static tri_t get_rs2(tri_t i) -{ - i = tri_sr(i, 18); - return tri_mask(i, 4); -} - -static tri_t get_imm4(tri_t i) -{ - i = tri_sr(i, 5); - return tri_mask(i, 4); -} - -static tri_t get_imm5(tri_t i) -{ - i = tri_sr(i, 22); - return tri_mask(i, 5); -} - -static tri_t get_imm9(tri_t i) -{ - i = tri_sr(i, 18); - return tri_mask(i, 9); -} - -static tri_t get_imm18(tri_t i) -{ - i = tri_sr(i, 9); - return tri_mask(i, 18); -} - -static tri_t get_fn0(tri_t i) -{ - i = tri_sr(i, 9); - return tri_mask(i, 5); -} - -/** @todo these macros should be ripped out into some common repository for - * reuse in an assembler */ -/* ALL HARDCODED VALUES ARE PLACEHOLDERS FOR NOW */ - -/* 0 */ -#define OP_IMM 0b0000000000 static void do_op_imm(struct cpu *cpu, tri_t i) { - tri_t rs1 = get_rs1(i); - tri_t rd = get_rd(i); + tri_t rd, fn0, rs1, imm9; + parse_i(i, &rd, &fn0, &rs1, &imm9); tri_t src = get_gpr(cpu, rs1); - tri_t imm9 = get_imm9(i); - tri_t fn0 = get_fn0(i); -#define ADDI 0 switch (fn0) { - case ADDI: { + case OP_IMM_ADDI: { tri_t r = tri_add(src, imm9); set_gpr(cpu, rd, r); break; @@ -173,23 +117,17 @@ static void do_op_imm(struct cpu *cpu, tri_t i) cpu->pc += 3; } -/* 1 */ -#define SYSTEM 0b0000000001 static void do_system(struct cpu *cpu, tri_t i) { - size_t rs1 = get_rs1(i); - size_t rd = get_rd(i); + tri_t rd, fn0, rs1, imm9; + parse_i(i, &rd, &fn0, &rs1, &imm9); tri_t src = get_gpr(cpu, rs1); - tri_t csr = get_imm9(i); - tri_t fn0 = get_fn0(i); - -#define CSRRW 0 switch (fn0) { - case CSRRW: { + case SYSTEM_CSRRW: { /* read existing value and replace it with rs1 */ - size_t n = get_csr_num(csr); + size_t n = get_csr_num(imm9); tri_t c = get_csr(cpu, n); set_csr(cpu, n, src); set_gpr(cpu, rd, c); @@ -204,27 +142,21 @@ static void do_system(struct cpu *cpu, tri_t i) cpu->pc += 3; } -/* -1 */ -#define STORE 0b0000000010 static void do_store(struct cpu *cpu, tri_t i) { - size_t rs1 = get_rs1(i); - size_t rs2 = get_rs2(i); - - tri_t src = get_gpr(cpu, rs2); - tri_t base = get_gpr(cpu, rs1); - tri_t imm4 = get_imm4(i); - tri_t imm5 = get_imm5(i); - tri_t fn0 = get_fn0(i); + tri_t imm4, fn0, rs1, rs2, imm5; + parse_s(i, &imm4, &fn0, &rs1, &rs2, &imm5); - tri_t imm = tri_sl(imm5, 4) | imm4; + tri_t imm9 = tri_sl(imm4, 5) | imm5; + tri_t base = get_gpr(cpu, rs2); + tri_t src = get_gpr(cpu, rs1); /* should maybe check that there's zeroes in other trits in fn0? */ int w = tri_get_trit(fn0, 4); /* somewhat unsure if mmu should function in trinary or binary at this * point */ - tri_t addr = tri_add(base, imm); + tri_t addr = tri_add(base, imm9); vm_t a = tri_to(addr); switch (w) { @@ -238,12 +170,10 @@ static void do_store(struct cpu *cpu, tri_t i) cpu->pc += 3; } -/* 3 */ -#define LUI 0b0000000100 static void do_lui(struct cpu *cpu, tri_t i) { - size_t rd = get_rd(i); - tri_t imm18 = get_imm18(i); + tri_t rd, imm18; + parse_u(i, &rd, &imm18); set_gpr(cpu, rd, tri_sl(imm18, 9)); cpu->pc += 3; } @@ -263,11 +193,11 @@ void cpu_run(struct cpu *cpu, vm_t start) /** @todo check for raised interrupts, illegal addr etc. */ /* check lowest five trits to determine opcode */ - switch (tri_mask(i, 5)) { - case LUI: do_lui(cpu, i); break; - case STORE: do_store(cpu, i); break; - case SYSTEM: do_system(cpu, i); break; - case OP_IMM: do_op_imm(cpu, i); break; + switch (parse_opcode(i)) { + case OPCODE_LUI: do_lui(cpu, i); break; + case OPCODE_STORE: do_store(cpu, i); break; + case OPCODE_SYSTEM: do_system(cpu, i); break; + case OPCODE_OP_IMM: do_op_imm(cpu, i); break; default: /** @todo raise illegal instruction exception */ fprintf(stderr, "illegal/unimplemented " "instruction at %lx, aborting\n", |