Start to rearrange archetecture specific code

arch/mips.c

@@ -0,0 +1,43 @@
+#if defined(__mips__)
+#include <stdint.h>
+
+void exit(int8_t status){
+  asm ( 
+    "move $a0, %0\n"
+    "li $v0, 4001\n"
+    "syscall\n"
+    :
+    : "r" (status)
+    : "a0", "v0"
+  );
+}
+
+intptr_t write(int32_t fd, const void* buf, intptr_t size){
+  intptr_t n_written = 0;
+  asm ( 
+    "li $a0, 1\n"
+    "move $a1, %0\n"
+    "move $a2, %1\n"
+    "li $v0, 4004\n"
+    "syscall\n"
+    : //TODO: n_written
+    : "r"(buf), "r"(count)
+    : "a0", "a1", "a2", "v0" //TODO: temp registers clobbered by syscall should probably also be listed but this fn returns right away so it should be fine?
+  );
+  return n_written;
+}
+//intptr_t read(int32_t fd, const void* buf, intptr_t size);
+
+uint32_t fork(){
+  int rtn;
+  asm ( 
+    "li $v0, 4002\n"
+    "syscall\n"
+    "move %0, $v0"
+    :"=r" (rtn)
+    : 
+    : "a0", "v0"
+  );
+  return (uint32_t)rtn;
+}
+#endif