checkpoint. we can fake syscall with the dummy gdt

1 files changed, 19 insertions, 0 deletions

diff --git a/service/lib/posix.c b/service/lib/posix.c
new file mode 100644
index 0000000..a912977
--- /dev/null
+++ b/service/lib/posix.c
@@ -0,0 +1,19 @@
+#include <unistd.h>
+
+ssize_t write(int fd, const void *buffer, size_t length)
+{
+	ssize_t result;
+
+	__asm__ (
+		"movq %0, %%rdi\n"
+		"movq %1, %%rsi\n"
+		"movq %2, %%rdx\n"
+		"movq $1, %%rax\n"
+		"syscall"
+		: "=a"(result)
+		: "g"(fd), "g"(buffer), "g"(length)
+		: "rdi", "rsi","rdx");
+
+	return result;
+}
+