Upload

Digital Research

CPM OPERATING SYSTEMS/CPM 68K/1.0X SOURCES/v101/boot/ldrif.s

@@ -0,0 +1,44 @@
+
+*****************************************
+*  Assembly Language Interface Routine  *
+*    for the CP/M-68K loader, cpmldr	*
+*					*
+*  It has one entry point:  _startld	*
+*  It sets up the stack and jumps to	*
+*	_ldcpm				*
+*****************************************
+
+	.globl	_startld	* public entry point
+	.globl	ldr		* label for library search
+
+	.globl	_bios		* external references
+	.globl	_ldcpm
+
+	.text
+
+ldr:
+_startld:
+	lea	stack,sp
+	clr.l	d0
+	jsr	_bios		* init the BIOS
+	move	#22,d0
+	move	#8,d1
+	move.l	#privexc,d2
+	jsr	_bios		* set exception for privilege violation
+	ori	#$2000,sr	* set supervisor state
+*				  if in user mode, will generate priv violation
+	lea	stack,sp
+	bra	_ldcpm
+
+
+privexc:
+	ori.w	#$2000,(sp)
+	rte
+
+
+	.bss
+
+	.ds.l	256
+stack:	.ds.w	1
+
+	.end