From 0d4e7b7146152ff9a818dd5fe5009333d9beb0eb Mon Sep 17 00:00:00 2001
From: Leo <erbl259-lmu@yahoo.de>
Date: Thu, 5 Aug 2010 20:27:44 +0000
Subject: [PATCH] * avr/z80.asm:   - Bugfix: SD card without partition table:
 Set size to 8MB.

git-svn-id: svn://cu.loc/avr-cpm/trunk@68 57430480-672e-4586-8877-bcf8adbbf3b7
---
 avrcpm/avr/z80.asm | 43 +++++++++++++++++++++++++++++--------------
 1 file changed, 29 insertions(+), 14 deletions(-)

diff --git a/avrcpm/avr/z80.asm b/avrcpm/avr/z80.asm
index 3aca645..4b0e507 100644
--- a/avrcpm/avr/z80.asm
+++ b/avrcpm/avr/z80.asm
@@ -376,7 +376,7 @@ clr_l:
 .endif
 
 	rcall printstr
-	.db "CPM on an AVR, v1.0",13,0,0
+	.db 13,"CPM on an AVR, v1.0",13,0
 
 
 .if MEMTEST
@@ -446,9 +446,6 @@ ramfillw:
 .endif
 
 
-	rcall printstr
-	.db "Initing mmc...",13,0
-	rcall mmcInit
 
 ;----------------------------------------------------------------------------
 
@@ -457,34 +454,49 @@ ramfillw:
 #define PART_START  8
 #define PART_SIZE  12
 
-;Load first sector from MMC (boot sector)
+	rcall printstr
+	.db "Initing mmc...",13,0
 
 boot_again:
-	ldi	yh,0
+	rcall mmcInit
+;Load first sector from MMC (boot sector)
+
+	ldi	yh,0			; Sector 0
 	ldi	yl,0
 	movw	x,y
 	rcall	mmcReadSect
 
 ;Test, if it has a valid MBR
 
-	lds	temp,hostbuf+510	;MBR signature (0xAA55)  at and of sector?
-	lds	temp2,hostbuf+511
+	ldi	yl,low(hostparttbl)
+	ldi	yh,high(hostparttbl)
+	ldi	zl,low(hostbuf+510-1)	;Point to last byte of partition table
+	ldi	zh,high(hostbuf+510-1)
+
+	ldi	opl,0			;opl holds number of found disks (paritions)
+	ldd	temp,z+1		;MBR signature (0xAA55)  at and of sector?
+	ldd	temp2,z+2
 	ldi	temp4,0xAA
 	cpi	temp,0x55		
 	cpc	temp2,temp4
-	ldi	opl,0			;opl holds number of found disks (paritions)
 	breq	boot_part
 
 ;No MBR, no partition table ...
 	inc	opl			;pretend we have one.
+	ldi	temp,high((1<<16) * 128/512)
+	std	y+0,_0			;start at beginning of card
+	std	y+1,_0
+	std	y+2,_0
+	std	y+3,_0
+	std	y+4,_0			;max CP/M 2.2 disk size
+	std	y+5,temp
+	std	y+6,_0
+	std	y+7,_0
 	rjmp	boot_ipl
 		
 ;Search Partition Table for CP/M partitions
 boot_part:
-	ldi	zl,low(hostbuf+510-64)
-	ldi	zh,high(hostbuf+510-64)
-	ldi	yl,low(hostparttbl)
-	ldi	yh,high(hostparttbl)
+	sbiw	z,63			;Now at first byte of partition table
 	ldi	oph,high(hostbuf+510)
 boot_ploop:
 	ldd	temp,z+PART_TYPE
@@ -574,7 +586,7 @@ iplwriteloop:
 	brne iplwriteloop
 	cpi zh,high(hostbuf+128)
 	brne iplwriteloop
-	rcall	dsk_boot		;init (de)blocking buffer
+	rcall	dsk_boot_nommc		;init (de)blocking buffer
 
 
 ;Init z80
@@ -998,6 +1010,9 @@ dskdbge:
 	rjmp	haltinv
 
 dsk_boot:
+; TODO: Partition table must also be reread to make this work.
+;	rcall mmcInit
+dsk_boot_nommc:
 	cbi	flags,hostact		;host buffer inactive
 	sts	unacnt,_0		;clear unalloc count
 	ret
-- 
2.39.2