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-rw-r--r--instruction.c50
-rw-r--r--memory.c10
-rw-r--r--memory.h2
-rw-r--r--nios2.c76
-rw-r--r--nios2.h5
5 files changed, 91 insertions, 52 deletions
diff --git a/instruction.c b/instruction.c
index 0ab99c8..6fd06dc 100644
--- a/instruction.c
+++ b/instruction.c
@@ -60,7 +60,7 @@ static int call(struct nios2 *cpu, uint32_t code)
J_TYPE(instr, code);
cpu->gp_regs[ra] = cpu->pc + 4;
- cpu->pc = (instr->imm26 * 4) | (cpu->pc & 0xF0000000);
+ cpu->pc = (cpu->pc & 0xF0000000) | (instr->imm26 * 4);
return PC_INC_BY_INSTR;
}
@@ -70,7 +70,7 @@ static int jmpi(struct nios2 *cpu, uint32_t code)
{
J_TYPE(instr, code);
- cpu->pc = (instr->imm26 * 4) | (cpu->pc & 0xF0000000);
+ cpu->pc = (cpu->pc & 0xF0000000) | (instr->imm26 * 4);
return PC_INC_BY_INSTR;
}
@@ -87,7 +87,7 @@ static int ldbu(struct nios2 *cpu, uint32_t code)
uint32_t addr = gp_regs[instr->a] + (int16_t) instr->imm16;
uint8_t byte;
- if (nios2_load_byte(cpu, addr, &byte))
+ if (nios2_load(cpu, addr, &byte, 1))
return INSTR_ERR;
gp_regs[instr->b] = (uint32_t) byte;
@@ -113,8 +113,9 @@ static int stb(struct nios2 *cpu, uint32_t code)
I_TYPE(instr, code);
uint32_t *gp_regs = cpu->gp_regs;
uint32_t addr = gp_regs[instr->a] + (int16_t) instr->imm16;
+ uint8_t data = gp_regs[instr->b] & 0xFF;
- if (nios2_store_byte(cpu, addr, gp_regs[instr->b] & 0xFF))
+ if (nios2_store(cpu, addr, &data, 1))
return INSTR_ERR;
return PC_INC_NORMAL;
@@ -138,7 +139,7 @@ static int ldb(struct nios2 *cpu, uint32_t code)
uint32_t addr = gp_regs[instr->a] + (int16_t) instr->imm16;
uint8_t byte;
- if (nios2_load_byte(cpu, addr, &byte))
+ if (nios2_load(cpu, addr, &byte, 1))
return INSTR_ERR;
gp_regs[instr->b] = (int32_t) byte;
@@ -146,10 +147,37 @@ static int ldb(struct nios2 *cpu, uint32_t code)
return PC_INC_NORMAL;
}
-/* */
-static int ldhu(struct nios2 *cpu __unused, uint32_t code __unused)
+/*
+ * if ((signed) rA >= (signed) @(IMM16))
+ * rB <- 1
+ * else
+ * rB <- 0
+ */
+static int cmpgei(struct nios2 *cpu, uint32_t code)
{
- /* TODO */
+ I_TYPE(instr, code);
+ uint32_t *gp_regs = cpu->gp_regs;
+
+ if ((int32_t) gp_regs[instr->a] >= (int32_t) ((int16_t) instr->imm16))
+ gp_regs[instr->b] = 1;
+ else
+ gp_regs[instr->b] = 0;
+
+ return PC_INC_NORMAL;
+}
+
+/* rB <- 0x0000 : Mem16[rA + @IMM16)] */
+static int ldhu(struct nios2 *cpu, uint32_t code)
+{
+ I_TYPE(instr, code);
+ uint32_t *gp_regs = cpu->gp_regs;
+ uint32_t addr = gp_regs[instr->a] + (int16_t) instr->imm16;
+ uint16_t halfword;
+
+ if (nios2_load(cpu, addr, &halfword, 2))
+ return INSTR_ERR;
+
+ gp_regs[instr->b] = (int32_t) halfword;
return PC_INC_NORMAL;
}
@@ -199,7 +227,7 @@ static int ldh(struct nios2 *cpu __unused, uint32_t code __unused)
}
/*
- * if ((signed) rA < (signed) @(IMM16)
+ * if ((signed) rA < (signed) @(IMM16))
* rB <- 1
* else
* rB <- 0
@@ -268,7 +296,7 @@ static int ldw(struct nios2 *cpu, uint32_t code)
uint32_t *gp_regs = cpu->gp_regs;
uint32_t addr = gp_regs[instr->a] + (int16_t) instr->imm16;
- if (nios2_load_word(cpu, addr, &gp_regs[instr->b]))
+ if (nios2_load(cpu, addr, &gp_regs[instr->b], 4))
return INSTR_ERR;
return PC_INC_NORMAL;
@@ -409,7 +437,7 @@ static struct instruction i_type_instructions[I_TYPE_COUNT] = {
[STB] = INSTRUCTION(stb),
[BR] = INSTRUCTION(br),
[LDB] = INSTRUCTION(ldb),
- [CMPGEI] = INSTRUCTION_UNIMPLEMENTED(cmpgei),
+ [CMPGEI] = INSTRUCTION(cmpgei),
[LDHU] = INSTRUCTION(ldhu),
[ANDI] = INSTRUCTION(andi),
[STH] = INSTRUCTION(sth),
diff --git a/memory.c b/memory.c
index 553766a..226eadf 100644
--- a/memory.c
+++ b/memory.c
@@ -27,6 +27,16 @@ void memory_set_byte(struct memory *mem, int32_t addr, uint8_t data)
base[addr - mem->image_base] = data;
}
+uint16_t memory_get_halfword(struct memory *mem, int32_t addr)
+{
+ return mem->base[(addr - mem->image_base) / 2];
+}
+
+void memory_set_halfword(struct memory *mem, int32_t addr, uint16_t data)
+{
+ mem->base[(addr - mem->image_base) / 2] = data;
+}
+
uint32_t memory_get_word(struct memory *mem, int32_t addr)
{
return mem->base[(addr - mem->image_base) / 4];
diff --git a/memory.h b/memory.h
index 80de90b..191b190 100644
--- a/memory.h
+++ b/memory.h
@@ -22,6 +22,8 @@ struct memory {
extern uint8_t memory_get_byte(struct memory *mem, int32_t addr);
extern void memory_set_byte(struct memory *mem, int32_t addr, uint8_t data);
+extern uint16_t memory_get_halfword(struct memory *mem, int32_t addr);
+extern void memory_set_halfword(struct memory *mem, int32_t addr, uint16_t data);
extern uint32_t memory_get_word(struct memory *mem, int32_t addr);
extern void memory_set_word(struct memory *mem, int32_t addr, uint32_t data);
diff --git a/nios2.c b/nios2.c
index a8ff9c4..2b2fec2 100644
--- a/nios2.c
+++ b/nios2.c
@@ -91,25 +91,38 @@ static bool is_mem_addr(struct memory *mem, uint32_t addr)
return false;
}
-int nios2_load_byte(struct nios2 *cpu, uint32_t addr, uint8_t *data)
+int nios2_load(struct nios2 *cpu, uint32_t addr, void *data, size_t size)
{
struct memory *mem = cpu->mem;
- dbg("ldb %08x\n", addr);
+ dbg("load%zu %08x\n", size * 8, addr);
if (is_mem_addr(mem, addr)) {
- dbg("load byte MEM\n");
- *data = memory_get_byte(mem, addr);
+ dbg("load MEM\n");
+ switch (size) {
+ case 1:
+ *((uint8_t *) data) = memory_get_byte(mem, addr);
+ break;
+ case 2:
+ *((uint16_t *) data) = memory_get_halfword(mem, addr);
+ break;
+ case 4:
+ *((uint32_t *) data) = memory_get_word(mem, addr);
+ break;
+ default:
+ err("Invalid size for load at %08x: %zu\n", addr, size);
+ return -1;
+ }
} else { /* must be I/O */
struct device *dev = device_get_by_addr(addr);
- dbg("load byte I/O\n");
+ dbg("load I/O\n");
if (unlikely(dev == NULL)) {
err("Reading data outside of device range (0x%08x)\n", addr);
return -1;
}
- if (dev->read(dev, addr, data, 1) != 1) {
+ if (dev->read(dev, addr, data, size) != 1) {
err("Read from device '%s' failed\n", dev->name);
return -1;
}
@@ -118,52 +131,39 @@ int nios2_load_byte(struct nios2 *cpu, uint32_t addr, uint8_t *data)
return 0;
}
-int nios2_store_byte(struct nios2 *cpu, uint32_t addr, uint8_t data)
+int nios2_store(struct nios2 *cpu, uint32_t addr, void *data, size_t size)
{
struct memory *mem = cpu->mem;
- dbg("stb %02x @ %08x\n", data, addr);
+ dbg("store%zu %08x\n", size, addr);
if (is_mem_addr(mem, addr)) {
- dbg("store byte MEM\n");
- memory_set_byte(mem, addr, data);
- } else { /* must be I/O */
- struct device *dev = device_get_by_addr(addr);
- dbg("store byte I/O\n");
- if (unlikely(dev == NULL)) {
- err("Writing data outside of device range (0x%08x)\n", addr);
+ dbg("store MEM\n");
+ switch (size) {
+ case 1:
+ memory_set_byte(mem, addr, *((uint8_t *) data));
+ break;
+ case 2:
+ memory_set_halfword(mem, addr, *((uint16_t *) data));
+ break;
+ case 4:
+ memory_set_word(mem, addr, *((uint32_t *) data));
+ break;
+ default:
+ err("Invalid size for store at %08x: %zu\n", addr, size);
return -1;
}
-
- if (dev->write(dev, addr, &data, 1) != 1) {
- err("Write to device '%s' failed\n", dev->name);
- return -1;
- }
- }
-
- return 0;
-}
-
-int nios2_load_word(struct nios2 *cpu, uint32_t addr, uint32_t *data)
-{
- struct memory *mem = cpu->mem;
-
- dbg("ldw %08x\n", addr);
-
- if (is_mem_addr(mem, addr)) {
- dbg("load word MEM\n");
- *data = memory_get_word(mem, addr);
} else { /* must be I/O */
struct device *dev = device_get_by_addr(addr);
- dbg("load byte I/O\n");
+ dbg("store I/O\n");
if (unlikely(dev == NULL)) {
- err("Reading data outside of device range (0x%08x)\n", addr);
+ err("Writing data outside of device range (0x%08x)\n", addr);
return -1;
}
- if (dev->read(dev, addr, (uint8_t *) data, 4) != 1) {
- err("Read from device '%s' failed\n", dev->name);
+ if (dev->write(dev, addr, data, size) != 1) {
+ err("Write to device '%s' failed\n", dev->name);
return -1;
}
}
diff --git a/nios2.h b/nios2.h
index b4ab4ff..a24ab1d 100644
--- a/nios2.h
+++ b/nios2.h
@@ -105,9 +105,8 @@ extern void nios2_exception(struct nios2 *cpu, uint8_t cause);
extern uint32_t nios2_fetch_instr(struct nios2 *cpu);
extern int nios2_execute_instr(struct nios2 *cpu, uint32_t instr);
-extern int nios2_load_byte(struct nios2 *cpu, uint32_t addr, uint8_t *data);
-extern int nios2_store_byte(struct nios2 *cpu, uint32_t addr, uint8_t data);
-extern int nios2_load_word(struct nios2 *cpu, uint32_t addr, uint32_t *data);
+extern int nios2_load(struct nios2 *cpu, uint32_t addr, void *data, size_t size);
+extern int nios2_store(struct nios2 *cpu, uint32_t addr, void *data, size_t size);
extern void nios2_dump_registers(struct nios2 *cpu);
generated by cgit v1.2.3-54-g00ecf (git 2.39.0) at 2024-04-25 07:32:57 +0000