Entry point for .prg / bootfloppy for zbeos.

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@23471 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/system/boot/platform/atari_m68k/shell.S

@@ -0,0 +1,126 @@
+/*
+ * Copyright 2004-2005, Axel Dörfler, axeld@pinc-software.de. All rights reserved.
+ * Copyright 2005, Ingo Weinhold, bonefish@users.sf.net.
+ * Copyright 2007, Haiku, Inc. All Rights Reserved.
+ * Distributed under the terms of the MIT license.
+ *
+ * Author:
+ *		François Revol, revol@free.fr.
+ */
+
+/**	This file contains the boot floppy and BFS boot block entry points for
+ *	the stage 2 boot loader.
+ * x86 ahead:
+ *	The floppy entry point is at offset 0. It's loaded at 0x07c0:0x000. It
+ *	will load the rest of the loader to 0x1000:0x0200 and execute it.
+ *	The BFS boot block will load the whole stage 2 loader to 0x1000:0x0000
+ *	and will then jump to 0x1000:0x0200 as its entry point.
+ *	This code will then switch to protected mode and will directly call
+ *	the entry function of the embedded ELF part of the loader.
+ */
+
+
+
+#include "toscalls.h"
+
+// 1 enabled verbose output
+//#define DEBUG 1
+
+#define GLOBAL(x) .globl x ; x
+#define FUNCTION(x) .global x; .type x,@function; x
+
+#define DRIVE_RETRIES 3
+	// when the drive reading fails for some reason, it will
+	// retry this many times until it will report a failure
+
+.text
+
+/* main entry point, both from the floppy boot and .prg */
+
+	// first, determine if .prg (user) or bootsect (super)
+	// Super()
+	move.l		SUP_INQUIRE,-(%sp)
+	move.w		#0x20,%d0
+	trap		#1
+	addq.l		#6,%sp
+	cmp.w		#SUP_SUPER,%d0
+	beq			floppy_start
+	bra			prg_start
+	bra			bootsect_start
+	rts
+floppy_start:
+
+floppy_end:
+	.org	FAILURE_STRING
+	.string " Loading failed! Press key to reboot.\r\n"
+	.org	DOT_STRING
+	.string	"."
+
+	.org	0x01fe
+	.word	0xaa55
+		// this bumps the "start" label to offset 0x0200 as
+		// expected by the BFS boot loader, and also marks
+		// this block as valid boot block for the BIOS
+
+prg_start:
+	// .prg:
+	// we need to switch to supervisor mode anyway
+	move.l		SUP_SET,-(%sp)
+	move.w		#0x20,%d0
+	trap		#1
+	addq.l		#6,%sp
+	move.l		%d0,saved_super_stack
+	// all done
+
+
+super_done:
+	
+	jsr			_start
+
+saved_super_stack:
+	.long	0
+
+GLOBAL(gBootedFromImage):
+	.byte	0
+
+GLOBAL(gBootDriveID):
+	.byte	0
+
+GLOBAL(gBootPartitionOffset):
+	.long	0
+
+
+
+	
+	lea.l	str,%a0
+.loopt:
+	move.b	(%a0)+,%d0
+	beq	.strout
+	bsr	putc
+	bra	.loopt
+.strout:
+	//Pterm0
+	move.w	#1,%d0
+	trap	#1
+
+	rts
+	
+.loop:
+	move	#'.',%d0
+	bsr		putc
+	bra		.loop
+	rts
+
+/* prints the char in d0.b to the console */
+putc:
+	movem.l	%a0,-(%sp)
+	move.w	%d0,-(%sp)
+	move.w	#DEV_CON,-(%sp)	// DEV_CON
+	move.w	#3,-(%sp)	// Bconout
+	trap	#13
+	add.l	#6,%sp
+	movem.l	(%sp)+,%a0
+	rts
+str:
+	.ascii "Haiku!"
+	.byte 0

src/system/boot/platform/atari_m68k/toscalls.h

@@ -37,6 +37,11 @@ extern "C" {
 #define RW_NORETRY		0x04
 #define RW_NOTRANSLATE	0x08
 
+#define SUP_USER		0
+#define SUP_SUPER		1
+#define SUP_SET			0
+#define SUP_INQUIRE		1
+
 #ifndef __ASSEMBLER__
 
 /* 
@@ -129,9 +134,8 @@ extern int32 xbios(uint16 nr, ...);
 
 extern int32 gemdos(uint16 nr, ...);
 
-#define SUP_USER		0
+#undef SUP_SET
-#define SUP_SUPER		1
+#undef SUP_INQUIRE
-
 #define SUP_SET			(void *)0
 #define SUP_INQUIRE		(void *)1