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Implemented basic arduino vm.

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Updated LDA to be M[D] = RX + IMM
Updated STA to be RD = M[RX + IMM]
Updated SYS to be RD = SYSCALL(RX, IMM)
Added error callback to VM, replaced printfs with callback.

Added syscalls.
This commit is contained in:
Sam Stevens
2018-10-22 00:01:47 +01:00
parent 6abacd4c1d
commit 600be14336
5 changed files with 377 additions and 113 deletions
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47
arduino/vm.c
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@@ -16,7 +16,6 @@ limitations under the License.
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include "vm.h"
VM *new_vm() {
@@ -94,7 +93,9 @@ void vm_step(VM *vm) {
uint8_t PC = vm->PC;
if (PC % 2 != 0) {
fprintf(stderr, "Halted. PC not aligned.\n");
if (vm->error != NULL) {
vm->error(VM_ERR_MISALIGN);
}
vm->halted = true;
return;
}
@@ -112,12 +113,32 @@ void vm_step(VM *vm) {
uint16_t temp16 = 0;
switch (inst.op) {
case OP_LDA:
vm_decode_Q(&inst, raw);
d = vm->M[inst.imm];
vm_decode_T(&inst, raw);
x = vm_get_r(vm, inst.rx);
temp16 = x;
temp16 += inst.imm;
if (temp16 < VM_MEM_SIZE) {
d = vm->M[temp16];
} else {
if (vm->error != NULL) {
vm->error(VM_ERR_OUT_OF_BOUNDS);
}
vm->halted = true;
}
break;
case OP_STA:
vm_decode_Q(&inst, raw);
vm->M[inst.imm] = vm_get_r(vm, inst.rd);
vm_decode_T(&inst, raw);
x = vm_get_r(vm, inst.rx);
temp16 = vm_get_r(vm, inst.rd);
temp16 += inst.imm;
if (temp16 < VM_MEM_SIZE) {
vm->M[temp16] = x;
} else {
if (vm->error != NULL) {
vm->error(VM_ERR_OUT_OF_BOUNDS);
}
vm->halted = true;
}
break;
case OP_LDI:
vm_decode_Q(&inst, raw);
@@ -172,11 +193,12 @@ void vm_step(VM *vm) {
d = x >> vm_get_r(vm, inst.imm);
break;
case OP_SYS:
vm_decode_Q(&inst, raw);
vm_decode_T(&inst, raw);
x = vm_get_r(vm, inst.rx);
if (vm->syscall != NULL) {
d = vm->syscall(vm, inst.imm);
d = vm->syscall(vm, x, inst.imm);
} else {
printf("SYSCALL #%d\n", inst.imm);
d = 0;
}
break;
case OP_JMP:
@@ -200,13 +222,14 @@ void vm_step(VM *vm) {
}
break;
case OP_HLT:
printf("Halted at 0x%04X\n", PC);
vm->halted = true;
break;
default:
printf("Unknown Instruction at 0x%04X: 0x%hhX\n", PC, inst.op);
if (vm->error != NULL) {
vm->error(VM_ERR_UNKNOWN_OP);
}
vm->halted = true;
break;
}
vm_put_r(vm, inst.rd, d);
}
}