Import backup from 2005-12-31

kernel/lang/lang.asm

@@ -3,6 +3,7 @@
 ; Created: 10/23/03
 ; Modified: 12/30/04
 
+[bits 32]
 
 %macro jzfar 1
 	jnz	%%skip
@@ -11,6 +12,42 @@
 
 %endmacro
 
+;implements a lock
+[global _lock]
+_lock:
+	push	ebp
+	mov	ebp, esp
+	push	eax
+	push	ebx
+	push	esi
+
+	mov	esi, [ebp + 8]
+_lock_loop0:
+	xor	eax, eax
+	mov	ebx, 1
+	cmpxchg	[esi], ebx
+	jnz	_lock_loop0		; failed to acquire lock
+
+	pop	esi
+	pop	ebx
+	pop	eax
+	pop	ebp
+	ret
+
+;releases a lock
+[global _unlock]
+_unlock:
+	push	ebp
+	mov	ebp, esp
+	push	esi
+
+	mov	esi, [ebp + 8]
+	mov	[esi], dword 0
+
+	pop	esi
+	pop	ebp
+	ret
+
 ;returns the value in the CR0 register
 ;extern dword read_cr0();
 [global _read_cr0]

kernel/lang/lang.h

@@ -9,6 +9,8 @@
 #include "hos_defines.h"
 
 /* lang.asm */
+void	lock(lock_t *addr);
+void	unlock(lock_t *addr);
 u32_t read_cr0();
 u32_t write_cr0(u32_t cr0);
 u32_t read_cr2();