syscalls: start trying to add nanosleep syscall

src/tasking/syscalls.c

@@ -7,6 +7,10 @@
 #include "../include/screen.h"
 #include "../include/fat.h"
 #include "../include/vfs.h"
+#include "../include/isr.h"
+#include "../include/task.h"
+
+extern void switchProcess(Process* next);
 
 #define STDIN_FILENO 0
 #define STDOUT_FILENO 1
@@ -299,6 +303,26 @@ uint32_t sys_brk(TrapFrame *tf)
     return (uint32_t)current->brk;
 }
 
+typedef struct timespec {
+    int32_t tv_sec;  // seconds
+    int32_t tv_nsec; // nanoseconds
+} timespec;
+
+uint32_t sys_nanosleep(TrapFrame *tf)
+{
+    timespec* duration = (timespec*)tf->ebx;
+    size_t ms = duration->tv_sec * 1000 + duration->tv_nsec / 1000000;
+    //debug_log("waiting for 0x%X ms\n", ms);
+    size_t start_time = timer_ticks;
+
+    current->wake_up_time = timer_ticks + ms;
+    //debug_log("setting wake up time to %X (current time is %X)\n", current->wake_up_time, timer_ticks);
+    
+    //TODO: find a way to call the scheduler from here without fucking shit up
+    
+    return 0;
+}
+
 void handle_syscall(TrapFrame *tf)
 {
     /*
@@ -347,6 +371,10 @@ void handle_syscall(TrapFrame *tf)
         case 0x2d://brk
             tf->eax = sys_brk(tf);
             break;
+        
+        case 0xa2://nanosleep
+            tf->eax = sys_nanosleep(tf);
+            break;
 
         default:
             debug_log("unknown syscall: %X\n", tf->eax);