can read character from keyboard now

mbr/Makefile

@@ -1,19 +1,24 @@
-PROG=mbr
-SRCS=$(wildcard *.S)
-OBJS=$(SRCS:.S=.o)
+SDIR ?= ../
+BDIR ?= ./
 
-LDFLAGS = -Ttext 0 -e 0
-CPPFLAGS = -I $(IDIR)
+PROG = mbr
+SRCS = mbr.S
+OBJS = mbr.o
+
+include $(SDIR)/Makefile.inc
+
+CFLAGS += -c -fno-pie
+LDFLAGS += -Ttext 0 -e 0
+CPPFLAGS += -DBOOTSEG=$(BOOTSEG) -DBOOTRELOCSEG=$(BOOTRELOCSEG) -DMBRSTACKOFF=$(MBRSTACKOFF)
+CPPFLAGS += -I $(SDIR)/
 
 ${PROG}: $(OBJS)
-	@rm -f $(PROG)
 	$(LD) $(LDFLAGS) -o $(PROG) $(OBJS)
-	objcopy -O binary mbr mbr.new
-	dd if=mbr.new of=mbr bs=512 count=1
-	rm -rf mbr.new
-	mv $(PROG) $(BDIR)
+	objcopy -S -O binary mbr mbr.new
+	dd if=mbr.new of=$(BDIR)/mbr bs=512 count=1
+	rm -f mbr.new
 
-$(OBJS): ../def.h
+$(OBJS): $(SDIR)/Makefile.inc $(SDIR)/btld_conf.h
 
 clean:
-	rm -f *.o *.bin $(PROG)
+	rm -f $(OBJS) $(PROG)

mbr/mbr.S

@@ -1,6 +1,6 @@
 .file "mbr.S"
 
-#include "def.h"
+#include "btld_conf.h"
 
 #define CHAR_LBA_READ '.'
 #define CHAR_R	'R'
@@ -8,7 +8,6 @@
 #define CHAR_L	'L'
 #define CHAR_B	'B'
 #define CHAR_G	'G'
-#define DBGMSG(c)	movb	$c, %al;	call	Lchr
 #define puts(s)		movw	$s, %si;	call	Lmessage
 
 // 0x07C00 - 0x07DFF	BIOS load us here
@@ -32,7 +31,6 @@ start:
 
 	// set up data segment
 	movw	%ax, %ds
-	DBGMSG(CHAR_S)
 
 	// relocate for PBR
 	// copy to 0x07a0
@@ -48,13 +46,12 @@ start:
 	ljmp	$BOOTRELOCSEG, $reloc
 
 reloc:
-	DBGMSG(CHAR_R)
 
 	pushw	%ds
 	popw	%es
 	pushw	%cs
 	popw	%ds
-	testb	$DOSACTIVE, %dl
+	testb	$0x80, %dl
 	jnz	drive_ok
 	puts(efdmbr)
 	jmp	stay_stopped
@@ -64,11 +61,10 @@ drive_ok:
 	movw	$NDOSPART, %cx
 
 find_active:
-	DBGMSG(CHAR_L)
 	movb	(%si), %al
-	cmpb	$DOSACTIVE, %al
+	cmpb	$0x80, %al
 	je	found
-	addw	$PARTSZ, %si
+	addw	$16, %si	//add partion size
 	loop	find_active
 
 no_part:
@@ -83,7 +79,6 @@ stay_stopped:
 	jmp	stay_stopped
 
 found:
-	DBGMSG(CHAR_B)
 	movb	%dl, %al
 	andb	$0x0f, %al
 	addb	$'0', %al
@@ -178,16 +173,15 @@ eread:	.asciz	"\r\nRead error\r\n"
 enoos:	.asciz	"No O/S\r\n"
 enoboot: .ascii	"No active partion"
 crlf: .asciz "\r\n"
-
 endofcode:
 	nop
 
-// partion table
 	. = DOSPARTOFF // partion table start address
-pt: .fill 0x40,1,0
+pt:
+	.fill 0x40,1,0
 
 	. = 0x1fe
 signature:
-	.short DOSMBR_SIGNATURE
+	.short 0xaa55 
 	. = 0x200