From de450bfb4354f716fb43fae69d90ed513068d10b Mon Sep 17 00:00:00 2001
From: Marvin Borner
Date: Sat, 28 Jan 2023 22:29:48 +0100
Subject: Rewrite, bootstrap

Rewriting without KVM, huge goals, won't finish, just for fun.
---
 src/linux.c | 41 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)
 create mode 100644 src/linux.c

(limited to 'src/linux.c')

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;
+}
-- 
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