diff options
| -rw-r--r-- | emulator/main.c | 58 | ||||
| -rw-r--r-- | main.asm | 23 |
2 files changed, 66 insertions, 15 deletions
diff --git a/emulator/main.c b/emulator/main.c index d48c049..ed875a3 100644 --- a/emulator/main.c +++ b/emulator/main.c @@ -216,6 +216,8 @@ struct Hart {
uint32_t pc;
uint32_t regs[32];
+ char* mem;
+ uint32_t mem_size;
};
void execute_op_imm(struct Hart* hart, uint32_t instruction)
@@ -334,24 +336,61 @@ void execute_branch(struct Hart* hart, uint32_t instruction) }
}
-uint32_t load_byte(struct Hart* hart, uint32_t address)
+inline uint32_t load_size(struct Hart* hart, uint32_t address, uint32_t size)
{
+ if ((address & 0x80000000) == 0)
+ {
+ assert(address + size < hart->mem_size);
+ uint32_t value = 0;
+ memcpy(&value, hart->mem + address, size);
+ return value;
+ }
+
return 0;
}
+uint32_t load_byte(struct Hart* hart, uint32_t address)
+{
+ return load_size(hart, address, 1);
+}
+
uint32_t load_half(struct Hart* hart, uint32_t address)
{
- return 0;
+ return load_size(hart, address, 2);
}
uint32_t load_word(struct Hart* hart, uint32_t address)
{
- return 0;
+ return load_size(hart, address, 4);
}
-void store_byte(struct Hart* hart, uint32_t address, uint8_t value) {}
-void store_half(struct Hart* hart, uint32_t address, uint16_t value) {}
-void store_word(struct Hart* hart, uint32_t address, uint32_t value) {}
+inline void store_size(struct Hart* hart, uint32_t address, uint32_t value, uint32_t size)
+{
+ if ((address & 0x80000000) == 0)
+ {
+ assert(address + size < hart->mem_size);
+ memcpy(hart->mem + address, &value, size);
+ }
+ else if (address == 0x80000000)
+ {
+ fwrite(&value, 1, size, stdout);
+ }
+}
+
+void store_byte(struct Hart* hart, uint32_t address, uint8_t value)
+{
+ store_size(hart, address, value, 1);
+}
+
+void store_half(struct Hart* hart, uint32_t address, uint16_t value)
+{
+ store_size(hart, address, value, 2);
+}
+
+void store_word(struct Hart* hart, uint32_t address, uint32_t value)
+{
+ store_size(hart, address, value, 4);
+}
void execute_op_load(struct Hart* hart, uint32_t instruction)
{
@@ -786,14 +825,13 @@ int main(int argc, char* argv[]) struct Hart hart = {0};
hart.pc = start_address;
+ hart.mem = mem;
+ hart.mem_size = mem_size;
while (true)
{
- uint32_t instruction = *(uint32_t*)(mem + hart.pc);
+ uint32_t instruction = load_word(&hart, hart.pc);
execute(&hart, instruction);
- printf("pc=%x x1=%d x2=%d x3=%d x4=%d\n",
- hart.pc, hart.regs[1], hart.regs[2], hart.regs[3], hart.regs[4]);
- fgetc(stdout);
}
return EXIT_SUCCESS;
@@ -1,9 +1,22 @@ .section .text
.global _main
+
+print:
+ li t1, 0x80000000
+l0:
+ lb t0, 0(a0)
+ beqz t0, l1
+ sb t0, 0(t1)
+ addi a0, a0, 1
+ j l0
+l1:
+ ret
+
_main:
- li x1, 5
- addi x2, x1, 45
+ la a0, my_str
+ call print
+
+halt: j halt
-loop:
- addi x2, x2, 1
- j loop
+.section .rodata
+my_str: .string "Hello, world!\n"
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