1 files changed, 69 insertions, 0 deletions
diff --git a/syscall.jai b/syscall.jai
new file mode 100644
index 0000000..46a9d84
--- /dev/null
+++ b/syscall.jai
@@ -0,0 +1,69 @@
+#import "Basic";
+#import "POSIX";
+
+// This prototype is suposed to allow me to use the "open" posix syscall
+// that returns a file-descriptor (fd) that can then be used by the mmap
+// syscall that allows to map a file to memory.
+//
+// Syscall info: https://filippo.io/linux-syscall-table/
+
+main :: () {
+    print("starting syscall\n");
+
+    sys_exit(-1);
+    fd := sys_open("./dummy");
+    print("fd is %\nerrno is %\n", fd, errno());
+    
+    print("done syscall\n");
+    LOOPER :: "\\|/-";
+    idx := 0;
+    loop: string;
+    loop.count = 1;
+    for 0..3 {
+        sleep_milliseconds(1000);
+        loop.data = *LOOPER.data[idx];
+        idx = (idx + 1) % LOOPER.count;
+        print("\rlooping %", loop);
+    }
+    
+    sys_close(fd);
+    print("\rclosed\n");
+    
+    for 0..3 {
+        sleep_milliseconds(1000);
+        loop.data = *LOOPER.data[idx];
+        idx = (idx + 1) % LOOPER.count;
+        print("\rlooping %", loop);
+    }
+}
+
+sys_open :: (path: string) -> fd: s64 {
+    SYS_OPEN :: 2;
+    return syscall(SYS_OPEN, cast(*s8)path.data, O_RDONLY);
+}
+
+sys_close :: (fd: s64) {
+    SYS_CLOSE :: 3;
+    syscall(SYS_CLOSE, fd);
+}
+
+sys_exit :: (status: s32) {
+#if OS == .WINDOWS {
+    // @Note TerminateProcess may be better, as it can't deadlock
+    ExitProcess :: (error_code: u32) #foreign kernel32;
+    ExitProcess(xx errno);
+}
+else #if OS == .LINUX {
+    SYS_EXIT_GROUP :: 231;
+    #if CPU==.X64 {
+        print("\rLINUX-ASM\n");
+        #asm SYSCALL_SYSRET {
+            mov eax: gpr === a,  SYS_EXIT_GROUP;
+            mov out: gpr === di,  status;
+            syscall t1:, t2:, eax, out;
+        };
+    } else {
+        syscall(SYS_EXIT_GROUP, status);
+    }
+}
+}