1 files changed, 58 insertions, 0 deletions
diff --git a/src/components/cpu/riscv/simple_riscv32.c b/src/components/cpu/riscv/simple_riscv32.c
new file mode 100644
index 0000000..1f19b1f
--- /dev/null
+++ b/src/components/cpu/riscv/simple_riscv32.c
@@ -0,0 +1,58 @@
+#include <gran/cpu/riscv/simple_riscv32.h>
+
+struct simple_riscv32 {
+	struct component component;
+
+	struct component *imem;
+	struct component *dmem;
+
+	/* have to be careful with x0 */
+	uint32_t regs[32];
+	uint32_t pc;
+};
+
+static uint32_t get_reg(struct simple_riscv32 *cpu, size_t i)
+{
+	assert(i < 32);
+
+	if (i == 0)
+		return 0;
+
+	return cpu->regs[i];
+}
+
+static void set_reg(struct simple_riscv32 *cpu, size_t i, uint32_t v)
+{
+	assert(i < 32);
+
+	if (i == 0)
+		return;
+
+	cpu->regs[i] = v;
+}
+
+static stat simple_riscv32_clock(struct simple_riscv32 *cpu)
+{
+	uint32_t insn = 0;
+	stat ret = read(cpu->imem, cpu->pc, sizeof(insn), &insn);
+	if (ret)
+		return ret;
+
+	/* @todo instruction decode and execution, not sure if this is too early
+	 * to start thinking about how to modularise stuff */
+	return OK;
+}
+
+struct componen *create_simple_riscv32(uint32_t start_pc, struct component *imem, struct component *dmem)
+{
+	struct component *new = calloc(1, sizeof(simple_riscv32));
+	if (!new)
+		return NULL;
+
+	new->component.clock = (clock_callback)simple_riscv32_clock;
+
+	new->pc = start_pc;
+	new->imem = imem;
+	new->dmem = dmem;
+	return new;
+}