Rewrite, bootstrap

Rewriting without KVM, huge goals, won't finish, just for fun.

1 files changed, 41 insertions, 0 deletions

diff --git a/src/linux.c b/src/linux.c
new file mode 100644
index 0000000..2e89049
--- /dev/null
+++ b/src/linux.c
@@ -0,0 +1,41 @@
+#include <stdint.h>
+#include <unistd.h>
+
+#include <cpu.h>
+#include <mem.h>
+#include <linux.h>
+#include <log.h>
+
+// TODO: Don't use unistd, emulate all syscalls for time-travel
+
+static void call_write(void)
+{
+	uint64_t fd = *(uint64_t *)cpu_get_reg(RDI);
+	char *buf = mem_phys(*(vaddr *)cpu_get_reg(RSI));
+	uint64_t count = *(uint64_t *)cpu_get_reg(RDX);
+	int ret = write(fd, buf, count);
+	cpu_set_reg(RAX, ret);
+}
+
+static void call_exit(void)
+{
+	int64_t code = *(int64_t *)cpu_get_reg(RDI);
+	logln("exiting with code %d", code);
+}
+
+int linux_call(void)
+{
+	uint64_t call = *(uint64_t *)cpu_get_reg(RAX);
+	switch (call) {
+	case 1:
+		call_write();
+		break;
+	case 60:
+		call_exit();
+		return ERR;
+	default:
+		errln("invalid syscall %d", call);
+		return ERR;
+	}
+	return OK;
+}