From 4580d576a88e95dec2750d37991f68f5b90080e0 Mon Sep 17 00:00:00 2001
From: Hojun-Cho <ghwns6743@gmail.com>
Date: Wed, 4 Dec 2024 17:17:53 +0900
Subject: [PATCH] can read character from keyboard now

---
 Makefile                  |   3 +-
 Makefile.inc              |  15 +-
 biosboot/Makefile         |  20 +-
 biosboot/biosboot.S       |  17 +-
 boot/Makefile             |  26 ++-
 boot/{conf.h => a20.c}    |  40 +---
 boot/boot.c               |  82 ++++----
 boot/console.c            |  26 +++
 boot/dat.h                |  38 ++++
 boot/def.h                |  47 +++++
 boot/{pio.h => fn.h}      |  14 +-
 boot/gdt.S                | 394 ++++++++++++++++++++++++++------------
 boot/ld.script            |  61 ++++--
 boot/print.c              |  70 +++++++
 boot/srt0.S               |  13 +-
 btld_conf.h               |  12 ++
 dat.h => btld_disk.h      |  18 --
 def.h                     |  22 ---
 installboot/Makefile      |  18 +-
 installboot/installboot.c |  39 ++--
 installmbr/Makefile       |  20 +-
 installmbr/installmbr.c   |  35 ++--
 mbr/Makefile              |  29 +--
 mbr/mbr.S                 |  20 +-
 u.h                       |  21 ++
 25 files changed, 729 insertions(+), 371 deletions(-)
 rename boot/{conf.h => a20.c} (51%)
 create mode 100644 boot/console.c
 create mode 100644 boot/dat.h
 create mode 100644 boot/def.h
 rename boot/{pio.h => fn.h} (60%)
 create mode 100644 boot/print.c
 create mode 100644 btld_conf.h
 rename dat.h => btld_disk.h (81%)
 delete mode 100644 def.h
 create mode 100644 u.h

diff --git a/Makefile b/Makefile
index 1671a58..852c58b 100644
--- a/Makefile
+++ b/Makefile
@@ -2,6 +2,7 @@ BDIR = build
 SUBDIRS = biosboot boot mbr installboot installmbr 
 
 all: $(BDIR) $(SUBDIRS) 
+	cp installboot/filecopy.sh $(BDIR)/
 
 $(BDIR):
 	mkdir -p $(BDIR)
@@ -10,6 +11,6 @@ clean: $(SUBDIRS)
 	rm -rf $(BDIR)
 
 $(SUBDIRS):
-	@make -sC $@ $(MAKECMDGOALS) BDIR=$(PWD)/$(BDIR) IDIR=$(PWD)
+	@make -C $@ $(MAKECMDGOALS) BDIR=$(PWD)/$(BDIR) SDIR=$(PWD)
 
 .PHONY: biosboot boot installboot mbr installmbr
diff --git a/Makefile.inc b/Makefile.inc
index b617a63..3e9e2a5 100644
--- a/Makefile.inc
+++ b/Makefile.inc
@@ -1,13 +1,14 @@
+
 LINKADDR = 0x40120
 LOADADDR = 0x40000
 BOOTMAGIC = 0xc001d00d
-BOOTREL = 0x60000
+BOOTSEG	= 0x7c0
+BOOTRELOCSEG = 0x7a0
+MBRSTACKOFF = 0xfffc
+BOOTSTACKOFF = 0xfffc
 
 CC=cc
-CFLAGS=-m32 -Wall -Werror -march=i386 -O0  -fno-stack-protector -ffreestanding -fno-builtin
-#CFLAGS=-m32  -march=i386 -O0  -fno-stack-protector -ffreestanding -fno-builtin
+CFLAGS= -m32 -march=i386 -Wall -Werror -march=i386 -O0  -fno-stack-protector -ffreestanding -fno-builtin -fno-builtin-function -fno-gnu-unique
 CPPFLAGS=-nostdinc
-LD=ld 
-AS=as
-ASFLAGS=-Wa,-O0,--32
-LDFLAGS=-melf_i386 -O0 -nostdlib -x -N -Bstatic -znorelro -no-pie 
+ASFLAGS=-Wa,--32,-O0
+LDFLAGS=-O0 -melf_i386 -nostdlib -x -N -Bstatic -znorelro -no-pie 
diff --git a/biosboot/Makefile b/biosboot/Makefile
index e16529e..80addde 100644
--- a/biosboot/Makefile
+++ b/biosboot/Makefile
@@ -1,18 +1,20 @@
-include ../*.inc
+SDIR ?= ../
+BDIR ?= ./
 
-PROG=biosboot
-SRCS=$(wildcard *.S)
-OBJS=$(SRCS:.S=.o)
+PROG = biosboot
+SRCS = biosboot.S
+OBJS = biosboot.o
 
-CFLAGS+=-c -fno-pie
-LDFLAGS+=-Ttext 0 -T ld.script
-CPPFLAGS+=-nostdinc -DLOADADDR=$(LOADADDR) -DLINKADDR=$(LINKADDR) -DBOOTMAGIC=$(BOOTMAGIC)
-CPPFLAGS+=-I $(IDIR)
+include $(SDIR)/Makefile.inc
+
+CFLAGS += -c -fno-pie
+LDFLAGS += -Ttext 0 -T ld.script
+CPPFLAGS += -DLOADADDR=$(LOADADDR) -DLINKADDR=$(LINKADDR) -DBOOTMAGIC=$(BOOTMAGIC) -DBOOTSEG=$(BOOTSEG)
 
 $(PROG): $(OBJS)
 	$(LD) $(LDFLAGS) -o $(BDIR)/$(PROG) $(OBJS)
 
-$(OBJS): ../def.h
+$(OBJS): $(SDIR)/Makefile.inc
 
 clean:
 	rm -f $(PROG) $(OBJS)
diff --git a/biosboot/biosboot.S b/biosboot/biosboot.S
index 4b7e60b..b077807 100644
--- a/biosboot/biosboot.S
+++ b/biosboot/biosboot.S
@@ -1,13 +1,14 @@
 .file "biosboot.S"
 
-#include "def.h"
-
 // 0x00000 -> 0x07BFF	our stack		(to  31k)
 // 0x07A00 -> 0x07BFF	typical MBR loc		(at  30k5)
 // 0x07C00 -> 0x07DFF	our code biosboot	(at  31k)
-// 0x07E00 -> ...    	/boot inode block	(at  31k5)
-// 0x07E00 -> ...    	(indirect block if nec)
-// 0x40000 -> ...	/boot			(at 256k)
+// 0x07E00 -> ...    	FAT table		(at  31k5)
+// 0x40000 -> ...	"boot" file		(at 256k)
+
+#define ELFMAGIC 0x464c457f  /* ELFMAGIC ("\7fELF") */
+#define FATSEG 0x07e0	/* FAT table segment */
+#define BOOTSTACKOFF ((BOOTSEG << 4) - 4)  /* stack starts here, grows down */
 
 #define PBR_READ_ERROR			'R'
 #define PBR_CANT_BOOT			'X'
@@ -71,7 +72,7 @@ main:
 load_boot:
 	start_cluster = .+1
 	movw	$0x9090, %ax
-	movw	$LOADSEG, %bx	 // destination
+	movw	$(LOADADDR >> 4), %bx	 // destination
 	movw	%bx, %di
 	movw	$FATSEG, %cx
 	movw	%cx, %es
@@ -158,7 +159,7 @@ Lchr:
 	ret
 
 done_load:
-	movw	$LOADSEG, %ax
+	movw	$(LOADADDR >> 4), %ax
 	movw	%ax, %es
 	cmpl	$ELFMAGIC, %es:0(,1)
 	je	exec_boot
@@ -202,4 +203,4 @@ err_id: .ascii	"?"
 crlf: .asciz	"\r\n"
 
 . = 0x200 - 2
-	.word DOSMBR_SIGNATURE
+	.word 0xaa55 
diff --git a/boot/Makefile b/boot/Makefile
index fb7361b..41ce878 100644
--- a/boot/Makefile
+++ b/boot/Makefile
@@ -1,19 +1,25 @@
-include ../*.inc
+SDIR ?= ../
+BDIR ?= ./
 
-PROG=boot
-CSRCS= $(wildcard *.c)
-SSRCS= $(wildcard *.S)
-OBJS = $(SSRCS:.S=.o) $(CSRCS:.c=.o)
+PROG = boot 
+SRCS = srt0.S gdt.S boot.c
+OBJS = srt0.o gdt.o boot.o
 
-CFLAGS+=-c -fno-pie
-CPPFLAGS+=-nostdinc -DLOADADDR=$(LOADADDR) -DLINKADDR=$(LINKADDR) -DBOOTMAGIC=$(BOOTMAGIC)
-LDFLAGS+= -s -T ld.script -Ttext=$(LINKADDR) --no-omagic -M
+ESRCS = console.c print.c a20.c
+OBJS += $(ESRCS:.c=.o)
+
+include $(SDIR)/Makefile.inc
+
+CFLAGS += -no-pie 
+CPPFLAGS += -DLOADADDR=$(LOADADDR) -DLINKADDR=$(LINKADDR) -DBOOTMAGIC=$(BOOTMAGIC) -DBOOTSTACKOFF=$(BOOTSTACKOFF)
+CPPFLAGS += -I $(SDIR)
+LDFLAGS += -s -Ttext=$(LINKADDR) -T ld.script --no-omagic -M
 
 ${PROG}: $(OBJS)
 	@rm -f $(PROG)
 	$(LD) $(LDFLAGS) -o $(BDIR)/$(PROG) $(OBJS)
 
-$(OBJS): conf.h pio.h
+$(OBJS): $(SDIR)/u.h def.h dat.h fn.h
 
 clean:
-	rm -f $(PROG) $(PROG).bin *.o
+	rm -f $(PROG) $(OBJS)
diff --git a/boot/conf.h b/boot/a20.c
similarity index 51%
rename from boot/conf.h
rename to boot/a20.c
index 58557dc..6279430 100644
--- a/boot/conf.h
+++ b/boot/a20.c
@@ -1,18 +1,7 @@
-#define elem(x) (sizeof(x)/sizeof((x)[0]))
+#include <u.h>
+#include "fn.h"
 
-// IO Port	Access Type	Purpose
-// 0x60	Read/Write	Data Port
-// 0x64	Read	Status Register
-// 0x64	Write	Command Register
-
-typedef struct{
-	char *name;
-	void (**probes)(void);
-	int cnt;
-}BootProbe;
-
-// for high memory
-static void
+void
 a20up(void)
 {
 	struct{
@@ -43,25 +32,4 @@ a20up(void)
 		;
 	while(inb(i8042.sport) & i8042.dib)	
 		inb(i8042.dport);
-}
-
-static void (*probe1[])(void) = {
-	a20up,
-};
-static void (*probe2[])(void) = {
-};
-
-static BootProbe probes[] = {
-	{"probing", probe1, elem(probe1) },
-	{"disk", probe2, elem(probe2) },
-};
-
-static void
-machdep(void)
-{
-	for(int i = 0; i < elem(probes); ++i){
-		BootProbe bp = probes[i];
-		for(int j = 0; j < bp.cnt; ++j)
-			bp.probes[j]();
-	}	
-}
+}
\ No newline at end of file
diff --git a/boot/boot.c b/boot/boot.c
index a7d62de..69035fd 100644
--- a/boot/boot.c
+++ b/boot/boot.c
@@ -1,50 +1,58 @@
+#include <u.h>
+#include "dat.h"
+#include "fn.h"
 
-typedef unsigned short u16;
-typedef unsigned char u8;
-typedef int dev_t;
 
-#include "pio.h"
-#include "conf.h"
+void (*probe1[])(void) = {
+	a20up,
+};
+void (*probe2[])(void) = {
+};
 
-#define VGA_WIDTH 80
-#define VGA_LENGTH 25
+BootProbe probes[] = {
+	{"probing", probe1, elem(probe1) },
+	{"disk", probe2, elem(probe2) },
+};
 
-char*
-memcpy(char *a, char *b, int l)
+ConDev condev = {
+	.getc = pcgetc,
+	.putc = pcputc,
+};
+
+// https://wiki.osdev.org/BIOS
+void
+machdep(void)
 {
-	for(int i = 0; i < l; ++i)
-		a[i] = b[i];
-	return a;
+	for(int i = 0; i < elem(probes); ++i){
+		BootProbe bp = probes[i];
+		for(int j = 0; j < bp.cnt; ++j)
+			bp.probes[j]();
+	}	
 }
 
-int
-strlen(char *s)
+static void
+puts(char *s)
 {
-	int i = 0;
-	for(; s[i]; ++i)
-		;
-	return i;
-}
-
-char*
-itostr(int n, char *s)
-{
-	char buf[16];	
-	char *p = buf;
-
-	do {
-		*p++ = n%16;
-	}while((n/=16) != 0);
-
-	while(p > buf){
-		*s++ = "0123456789abcdef"[(int)*--p];
-	}
-	return s;
+	for(;*s;++s)	
+		putchar(*s);
 }
 
 void
-boot(dev_t bootdev)
+boot(int bootdev)
 {
-	machdep();
-	for(;;);
+	char buf[8192];
+
+	machdep();	
+	putchar('\n');
+	for(;;){
+		int i=0, c=0;
+
+		puts("\nboot >> ");
+		do{
+			c = getchar();
+			buf[i++] = c;
+		}while(c != '\n' && i < sizeof(buf) - 1);
+		buf[i-1] = 0;
+		puts(buf);
+	}
 }
diff --git a/boot/console.c b/boot/console.c
new file mode 100644
index 0000000..0f46609
--- /dev/null
+++ b/boot/console.c
@@ -0,0 +1,26 @@
+#include <u.h>
+#include "fn.h"
+
+// https://stanislavs.org/helppc/int_16.html
+
+void
+pcputc(int dev, int c)
+{
+	__asm volatile("int $0x30" : : "a" (c | 0xe00), "b" (1) : "%ecx", "%edx", "cc" );
+}
+
+int
+pcgetc(int dev)
+{
+	register int rv;
+
+	// wait for available
+	do{
+		__asm volatile("int $0x36; setnz %b0" : "=a" (rv) :
+		    "0" (0x100) : "%ecx", "%edx", "cc" );
+	}while((rv & 0xff) == 0);
+
+	__asm volatile("int $0x36" : "=a" (rv) :
+	    "0" (0x000) : "%ecx", "%edx", "cc" );
+	return rv&0xff;
+}
\ No newline at end of file
diff --git a/boot/dat.h b/boot/dat.h
new file mode 100644
index 0000000..085d5ac
--- /dev/null
+++ b/boot/dat.h
@@ -0,0 +1,38 @@
+// IO Port	Access Type	Purpose
+// 0x60	Read/Write	Data Port
+// 0x64	Read	Status Register
+// 0x64	Write	Command Register
+
+struct BIOSreg{
+	u32 ax; 
+	u32 cx; 
+	u32 dx; 
+	u32 bx; 
+	u32 bp; 
+	u32 si; 
+	u32 di; 
+	u32 ds; 
+	u32 es; 
+}__attribute__((packed));
+
+
+typedef struct{
+	char *name;
+	void (**probes)(void);
+	int cnt;
+}BootProbe;
+
+typedef struct{
+	int (*getc)(int);
+	void (*putc)(int, int);
+	int	dev;
+}ConDev;
+
+// gdt.S
+extern volatile struct BIOSreg BIOSreg;
+
+// boot.c
+extern void (*probe1[])(void);
+extern void (*probe2[])(void);
+extern BootProbe probes[];
+extern ConDev condev;
\ No newline at end of file
diff --git a/boot/def.h b/boot/def.h
new file mode 100644
index 0000000..4c48ac6
--- /dev/null
+++ b/boot/def.h
@@ -0,0 +1,47 @@
+// Trap
+#define	T_PRIVINFLT	 0	/* privileged instruction */
+#define	T_BPTFLT	 1	/* breakpoint trap */
+#define	T_ARITHTRAP	 2	/* arithmetic trap */
+#define	T_RESERVED	 3	/* reserved fault base */
+#define	T_PROTFLT	 4	/* protection fault */
+#define	T_TRCTRAP	 5	/* trace trap */
+#define	T_PAGEFLT	 6	/* page fault */
+#define	T_ALIGNFLT	 7	/* alignment fault */
+#define	T_DIVIDE	 8	/* integer divide fault */
+#define	T_NMI		 9	/* non-maskable interrupt */
+#define	T_OFLOW		10	/* overflow trap */
+#define	T_BOUND		11	/* bounds check fault */
+#define	T_DNA		12	/* device not available fault */
+#define	T_DOUBLEFLT	13	/* double fault */
+#define	T_FPOPFLT	14	/* fp coprocessor operand fetch fault (![P]Pro)*/
+#define	T_TSSFLT	15	/* invalid tss fault */
+#define	T_SEGNPFLT	16	/* segment not present fault */
+#define	T_STKFLT	17	/* stack fault */
+#define	T_MACHK		18	/* machine check ([P]Pro) */
+#define	T_XFTRAP	19	/* SIMD FP exception */
+
+/* memory segment types */
+#define	SDT_MEMRO	16	/* memory read only */
+#define	SDT_MEMROA	17	/* memory read only accessed */
+#define	SDT_MEMRW	18	/* memory read write */
+#define	SDT_MEMRWA	19	/* memory read write accessed */
+#define	SDT_MEMROD	20	/* memory read only expand dwn limit */
+#define	SDT_MEMRODA	21	/* memory read only expand dwn limit accessed */
+#define	SDT_MEMRWD	22	/* memory read write expand dwn limit */
+#define	SDT_MEMRWDA	23	/* memory read write expand dwn limit acessed */
+#define	SDT_MEME	24	/* memory execute only */
+#define	SDT_MEMEA	25	/* memory execute only accessed */
+#define	SDT_MEMER	26	/* memory execute read */
+#define	SDT_MEMERA	27	/* memory execute read accessed */
+#define	SDT_MEMEC	28	/* memory execute only conforming */
+#define	SDT_MEMEAC	29	/* memory execute only accessed conforming */
+#define	SDT_MEMERC	30	/* memory execute read conforming */
+#define	SDT_MEMERAC	31	/* memory execute read accessed conforming */
+
+#define S16TEXT	0x18	// segment selector of text section
+#define S16DATA	0x20
+#define S32TEXT	0x08	// segment selector of text section
+#define S32DATA	0x10
+#define	SDT_SYS386TGT	15	/* system 386 trap gate */
+
+#define CR0_PE	0x01	// protected mode enable
\ No newline at end of file
diff --git a/boot/pio.h b/boot/fn.h
similarity index 60%
rename from boot/pio.h
rename to boot/fn.h
index 80daec0..bc3c673 100644
--- a/boot/pio.h
+++ b/boot/fn.h
@@ -1,3 +1,15 @@
+
+// console.c
+int pcgetc(int dev);
+void pcputc(int dev, int c);
+
+// print.c
+void putchar(int c);
+int getchar(void);
+
+// a20.c
+void a20up(void);
+
 static __inline void
 outb(int port, u8 data)
 {
@@ -11,4 +23,4 @@ inb(int port)
 
 	__asm volatile("inb %w1,%0" : "=a" (data) : "d" (port));
 	return data;
-};
+}
\ No newline at end of file
diff --git a/boot/gdt.S b/boot/gdt.S
index b636223..0689af0 100644
--- a/boot/gdt.S
+++ b/boot/gdt.S
@@ -1,71 +1,95 @@
 .file "gdt.S"
 
-// Trap
-#define	T_PRIVINFLT	 0	/* privileged instruction */
-#define	T_BPTFLT	 1	/* breakpoint trap */
-#define	T_ARITHTRAP	 2	/* arithmetic trap */
-#define	T_RESERVED	 3	/* reserved fault base */
-#define	T_PROTFLT	 4	/* protection fault */
-#define	T_TRCTRAP	 5	/* trace trap */
-#define	T_PAGEFLT	 6	/* page fault */
-#define	T_ALIGNFLT	 7	/* alignment fault */
-#define	T_DIVIDE	 8	/* integer divide fault */
-#define	T_NMI		 9	/* non-maskable interrupt */
-#define	T_OFLOW		10	/* overflow trap */
-#define	T_BOUND		11	/* bounds check fault */
-#define	T_DNA		12	/* device not available fault */
-#define	T_DOUBLEFLT	13	/* double fault */
-#define	T_FPOPFLT	14	/* fp coprocessor operand fetch fault (![P]Pro)*/
-#define	T_TSSFLT	15	/* invalid tss fault */
-#define	T_SEGNPFLT	16	/* segment not present fault */
-#define	T_STKFLT	17	/* stack fault */
-#define	T_MACHK		18	/* machine check ([P]Pro) */
-#define	T_XFTRAP	19	/* SIMD FP exception */
+#include "def.h"
 
-/* memory segment types */
-#define	SDT_MEMRO	16	/* memory read only */
-#define	SDT_MEMROA	17	/* memory read only accessed */
-#define	SDT_MEMRW	18	/* memory read write */
-#define	SDT_MEMRWA	19	/* memory read write accessed */
-#define	SDT_MEMROD	20	/* memory read only expand dwn limit */
-#define	SDT_MEMRODA	21	/* memory read only expand dwn limit accessed */
-#define	SDT_MEMRWD	22	/* memory read write expand dwn limit */
-#define	SDT_MEMRWDA	23	/* memory read write expand dwn limit acessed */
-#define	SDT_MEME	24	/* memory execute only */
-#define	SDT_MEMEA	25	/* memory execute only accessed */
-#define	SDT_MEMER	26	/* memory execute read */
-#define	SDT_MEMERA	27	/* memory execute read accessed */
-#define	SDT_MEMEC	28	/* memory execute only conforming */
-#define	SDT_MEMEAC	29	/* memory execute only accessed conforming */
-#define	SDT_MEMERC	30	/* memory execute read conforming */
-#define	SDT_MEMERAC	31	/* memory execute read accessed conforming */
+#define GEN_LABEL(n)	X##n
 
-#define S32TEXT	0x08	// segment selector of text section
-#define	SDT_SYS386TGT	15	/* system 386 trap gate */
+// idt entry
+#define idte(e) 			\
+	movl	$GEN_LABEL(e), %eax ;	\
+	call	entry 
 
-#define IPROC(n)	X##n
-#define idte(e) \
-	movl $IPROC(e), %eax ; call entry_idt
+// idt bios entry
+#define idtbe(b)	idte(emu##b)
 
-#define IENTRY_ERR(name,err) \
-IPROC(name): \
-	pushl	$err ; \
-	jmp 1f	
+#define GEN_TRAP(name, err)	\
+	GEN_LABEL(name):	\
+		pushl	$err;	\
+		jmp 1f	
+
+#define	GEN_EMU(n)		\
+	GEN_LABEL(emu##n): 	\
+		pushl $n; 	\
+		jmp 1f
+
+
+#define prot2real					\
+	ljmp	$S16TEXT, $1f - LINKADDR;		\
+1:							\
+	.code16; 					\
+	movw	$S16DATA, %ax;				\
+	movw	%ax, %ds;				\
+	movw	%ax, %es;				\
+							\
+	movl	%cr0, %eax;				\
+	andl	$~CR0_PE, %eax;				\
+	movl	%eax, %cr0;				\
+							\
+	data32 ljmp $(LINKADDR >> 4), $1f - LINKADDR;	\
+1:							\
+	movw	%cs, %ax;				\
+	movw	%ax, %ds;				\
+	movw	%ax, %es;				\
+	xorw	%ax, %ax;				\
+	movw	%ax, %ss;				\
+	data32 addr32	lidt (Idtr_real - LINKADDR);
+
+#define real2prot					\
+	movw	$LINKADDR >> 4, %ax;			\
+	movw	%ax, %ds;				\
+	data32	addr32 lgdt (Gdtr - LINKADDR);		\
+							\
+	movl	%cr0, %eax;				\
+	orl	$CR0_PE, %eax;				\
+	movl	%eax, %cr0;				\
+							\
+	data32 ljmp	$S32TEXT, $1f;			\
+1:							\
+	.code32;					\
+	mov	$S32DATA, %eax;				\
+	mov	%ax, %ds;				\
+	mov	%ax, %ss;				\
+	mov	%ax, %es;				\
+							\
+	lidt	Idtr;
+
+.text
+.globl	BIOSreg	
+BIOSreg:
+	BIOS_AX: .long 0 
+	BIOS_CX: .long 0 
+	BIOS_DX: .long 0 
+	BIOS_BX: .long 0 
+	BIOS_BP: .long 0 
+	BIOS_SI: .long 0 
+	BIOS_DI: .long 0 
+	BIOS_DS: .long 0 
+	BIOS_ES: .long 0 
 
 .text
 .code32
-.globl	pmm_init
+.globl	pmode_init	
 
-entry_idt:
 //	Table
-//		IDTR offset + 0 : entry 0
-//		IDTR offset + 8 : entry 1
-//		
+//	IDTR offset + 0 : entry 0
+//	IDTR offset + 8 : entry 1
+//	
 //	Gate Descriptor
-//		63 ~ 48	: offset low
-//		47 ~ 32	: info
-//		31 ~ 16	: segment selector
-//		15 ~ 0	: offset high
+//	63 ~ 48	: offset low
+//	47 ~ 32	: info
+//	31 ~ 16	: segment selector
+//	15 ~ 0	: offset high
+entry:
 	movw	%ax, (%ebx)
 	movw	$S32TEXT, 2(%ebx)
 	movw	$((0x80|SDT_SYS386TGT) << 8), 4(%ebx)
@@ -74,8 +98,9 @@ entry_idt:
 	addl	$8, %ebx
 	ret
 
+// init IDT for protected mode
 	.align 8, 0x90
-pmm_init:
+pmode_init:
 	movl	$idt, %ebx
 	movl	$Idtr, %eax
 	movw	$(640 - 1), (%eax)
@@ -88,6 +113,15 @@ pmm_init:
 	idte(xx); idte(xx); idte(xx);  idte(xx); idte(xx); idte(xx)
 	idte(xx); idte(xx); idte(xx);  idte(xx); idte(xx); idte(xx)
 	idte(xx) 
+	/* BIOS interrupt call (32-63) */
+	idtbe(0);  idtbe(1);  idtbe(2);  idtbe(3);  idtbe(4);  idtbe(5)
+	idtbe(6);  idtbe(7);  idtbe(8);  idtbe(9);  idtbe(10); idtbe(11)
+	idtbe(12); idtbe(13); idtbe(14); idtbe(15); idtbe(16); idtbe(17)
+	idtbe(18); idtbe(19); idtbe(20); idtbe(21); idtbe(22); idtbe(23)
+	idtbe(24); idtbe(25); idtbe(26); idtbe(27); idtbe(28); idtbe(29)
+	idtbe(30); idtbe(31); idtbe(32); idtbe(33); idtbe(34); idtbe(35)
+	idtbe(36); idtbe(37); idtbe(38); idtbe(39); idtbe(40); idtbe(41)
+	idtbe(42); idtbe(43); idtbe(44); idtbe(45); idtbe(46); idtbe(47)
 
 	lidt	Idtr
 	ret
@@ -105,86 +139,204 @@ Idtr:
 
 	.text
 	.align	8
-gdt:
-		/* 0x00 : null */
-	.space	8
-		/* 0x08 : flat code */
-	.word	0xFFFF			# lolimit
-	.word	0			# lobase
-	.byte	0			# midbase
-	.byte	SDT_MEMERAC | 0 | 0x80	# RXAC, dpl = 0, present
-	.byte	0xf | 0 | 0x40 | 0x80	# hilimit, xx, 32bit, 4k granularity
-	.byte	0			# hibase
-		/* 0x10 : flat data */
-	.word	0xFFFF			# lolimit
-	.word	0			# lobase
-	.byte	0			# midbase
-	.byte	SDT_MEMRWA | 0 | 0x80	# RWA, dpl = 0, present
-	.byte	0xf | 0 | 0x40 | 0x80	# hilimit, xx, 32bit, 4k granularity
-	.byte	0			# hibase
-		/* 0x18 : 16 bit code */
-	.word	0xFFFF			# lolimit
-	.word	(LINKADDR & 0xffff)	# lobase
-	.byte	(LINKADDR >> 16) & 0xff	# midbase
-	.byte	SDT_MEMERAC | 0 | 0x80	# RXAC, dpl = 0, present
-	.byte	0x0 | 0 | 0 | 0		# hilimit, xx, 16bit, byte granularity
-	.byte	(LINKADDR >> 20) & 0xff	# hibase
-		/* 0x20 : 16 bit data */
-	.word	0xFFFF			# lolimit
-	.word	(LINKADDR & 0xffff)	# lobase
-	.byte	(LINKADDR >> 16) & 0xff	# midbase
-	.byte	SDT_MEMRWA | 0 | 0x80	# RWA, dpl = 0, present
-	.byte	0x0 | 0 | 0 | 0		# hilimit, xx, 16bit, byte granularity
-	.byte	(LINKADDR >> 20) & 0xff	# hibase
+	.globl	Idtr_real
+Idtr_real:
+	.word	1023 // 256 entry, 1k
+	.long	0
+	.word	0
+
+	.align	8
+gdt:
+	/* 0x00 : null */
+	.space	8
+	/* 0x08 : flat code */
+	.word	0xFFFF		 // lolimit
+	.word	0		 // lobase
+	.byte	0		 // midbase
+	.byte	SDT_MEMERAC | 0 | 0x80	 // RXAC, dpl = 0, present
+	.byte	0xf | 0 | 0x40 | 0x80	 // hilimit, xx, 32bit, 4k granularity
+	.byte	0		 // hibase
+	/* 0x10 : flat data */
+	.word	0xFFFF		 // lolimit
+	.word	0		 // lobase
+	.byte	0		 // midbase
+	.byte	SDT_MEMRWA | 0 | 0x80	 // RWA, dpl = 0, present
+	.byte	0xf | 0 | 0x40 | 0x80	 // hilimit, xx, 32bit, 4k granularity
+	.byte	0		 // hibase
+	/* 0x18 : 16 bit code */
+	.word	0xFFFF		// lolimit
+	.word	(LINKADDR & 0xffff)	 // lobase
+	.byte	(LINKADDR >> 16) & 0xff	 // midbase
+	.byte	SDT_MEMERAC | 0 | 0x80	 // RXAC, dpl = 0, present
+	.byte	0x0 | 0 | 0 | 0	 // hilimit, xx, 16bit, byte granularity
+	.byte	(LINKADDR >> 20) & 0xff	 // hibase
+	/* 0x20 : 16 bit data */
+	.word	0xFFFF		 // lolimit
+	.word	(LINKADDR & 0xffff)	 // lobase
+	.byte	(LINKADDR >> 16) & 0xff	 // midbase
+	.byte	SDT_MEMRWA | 0 | 0x80	 // RWA, dpl = 0, present
+	.byte	0x0 | 0 | 0 | 0	 // hilimit, xx, 16bit, byte granularity
+	.byte	(LINKADDR >> 20) & 0xff	 // hibase
 
-	
 //	Register GDT 
 .globl	Gdtr
 Gdtr:
-	.word	. - gdt -1
+	.word	. - gdt - 1
 	.long	gdt
 	.word	0
 
 // ENTRY Reserved
-IPROC(xx):
+GEN_LABEL(xx):
 	pushl	$1
-	pushl	$T_RESERVED
 	jmp	1f
 
 // trap entry points
-IENTRY_ERR(de,T_DIVIDE)	/* #DE divide by zero */
-IENTRY_ERR(db,T_TRCTRAP)	/* #DB debug */
-IENTRY_ERR(nmi,T_NMI)		/* NMI */
-IENTRY_ERR(bp,T_BPTFLT)	/* #BP breakpoint */
-IENTRY_ERR(of,T_OFLOW)	/* #OF overflow */
-IENTRY_ERR(br,T_BOUND)	/* #BR BOUND range exceeded */
-IENTRY_ERR(ud,T_PRIVINFLT)	/* #UD invalid opcode */
-IENTRY_ERR(nm,T_DNA)		/* #NM device not available */
-IENTRY_ERR(df,T_DOUBLEFLT)		/* #DF double fault */
-IENTRY_ERR(fo,T_FPOPFLT)	/* #FO coprocessor segment overrun */
-IENTRY_ERR(ts,T_TSSFLT)		/* #TS invalid TSS */
-IENTRY_ERR(np,T_SEGNPFLT)		/* #NP segment not present */
-IENTRY_ERR(ss,T_STKFLT)		/* #SS stack fault */
-IENTRY_ERR(gp,T_PROTFLT)		/* #GP general protection */
-IENTRY_ERR(pf,T_PAGEFLT)		/* #PF page fault */
-IENTRY_ERR(mf,T_ARITHTRAP)	/* #MF floating point error */
-IENTRY_ERR(ac,T_ALIGNFLT)		/* #AC alignment check */
-IENTRY_ERR(mc,T_MACHK)		/* #MC machine check */
-
+GEN_TRAP(de,T_DIVIDE)	/* DE divide by zero */
+GEN_TRAP(db,T_TRCTRAP)	/* DB debug */
+GEN_TRAP(nmi,T_NMI)	/* NMI */
+GEN_TRAP(bp,T_BPTFLT)	/* BP breakpoint */
+GEN_TRAP(of,T_OFLOW)	/* OF overflow */
+GEN_TRAP(br,T_BOUND)	/* BR BOUND range exceeded */
+GEN_TRAP(ud,T_PRIVINFLT)	/* UD invalid opcode */
+GEN_TRAP(nm,T_DNA)	/* NM device not available */
+GEN_TRAP(df,T_DOUBLEFLT)	/* DF double fault */
+GEN_TRAP(fo,T_FPOPFLT)	/* FO coprocessor segment overrun */
+GEN_TRAP(ts,T_TSSFLT)	/* TS invalid TSS */
+GEN_TRAP(np,T_SEGNPFLT)	/* NP segment not present */
+GEN_TRAP(ss,T_STKFLT)	/* SS stack fault */
+GEN_TRAP(gp,T_PROTFLT)	/* GP general protection */
+GEN_TRAP(pf,T_PAGEFLT)	/* PF page fault */
+GEN_TRAP(mf,T_ARITHTRAP)	/* MF floating point error */
+GEN_TRAP(ac,T_ALIGNFLT)	/* AC alignment check */
+GEN_TRAP(mc,T_MACHK)	/* MC machine check */
 1:
-	jmp	alltraps
-
-// in boot mode don't want handle trap
-alltraps:
+	popl	%ecx // what trap
 	hlt
-	iret
+	jmp	1b
+
+GEN_EMU(0);  GEN_EMU(1);  GEN_EMU(2);  GEN_EMU(3)
+GEN_EMU(4);  GEN_EMU(5);  GEN_EMU(6);  GEN_EMU(7)
+GEN_EMU(8);  GEN_EMU(9);  GEN_EMU(10); GEN_EMU(11)
+GEN_EMU(12); GEN_EMU(13); GEN_EMU(14); GEN_EMU(15)
+GEN_EMU(16); GEN_EMU(17); GEN_EMU(18); GEN_EMU(19)
+GEN_EMU(20); GEN_EMU(21); GEN_EMU(22); GEN_EMU(23)
+GEN_EMU(24); GEN_EMU(25); GEN_EMU(26); GEN_EMU(27)
+GEN_EMU(28); GEN_EMU(29); GEN_EMU(30); GEN_EMU(31)
+GEN_EMU(32); GEN_EMU(33); GEN_EMU(34); GEN_EMU(35)
+GEN_EMU(36); GEN_EMU(37); GEN_EMU(38); GEN_EMU(39)
+GEN_EMU(40); GEN_EMU(41); GEN_EMU(42); GEN_EMU(43)
+GEN_EMU(44); GEN_EMU(45); GEN_EMU(46); GEN_EMU(47)
+1:	jmp	EMUh
+
 
 // bios interrupt entry point
-// 	switch to real to protected mode and emulate 16bit mode
-
+// switch to real to protected mode and emulate 16bit mode
 	.globl	EMUh
 	.align	8, 0x90
-EMUh:
-	pushl	%eax
+EMUh: // build stack for real mode
+	mov	%eax, 5f	// save number to code segment not in the data segment
+	pop	%eax
 
-.end
\ No newline at end of file
+	pusha
+	push	%ds	
+	push	%es
+	push	%fs
+	push	%gs
+
+	movb	%al, intno	// save BIOS int vector
+
+// BIOS_regs is  area for saving the contents of registers returned by the BIOS during a BIOS CALL
+	movl	BIOS_ES, %eax
+	movl	$0x00, %eax
+	mov	%eax, 7f
+	movl	BIOS_DS, %eax
+	movl	$0x00, %eax
+	mov	%eax, 6f	
+
+	prot2real
+
+	// save ds to stack and rewrite es, ds
+	push	%ds
+
+	// data32 movl $Leax, %eax
+	.byte	0x66, 0xb8
+7:	.long	0x90909090
+	mov	%ax, %es
+
+	// data32 movl $Leax, %eax
+	.byte	0x66, 0xb8
+6:	.long	0x90909090
+	mov	%ax, %ds
+
+	// data32 movl $Leax, %eax => now ax is holding interrupt nummber
+	.byte	0x66, 0xb8
+5:	.long	0x90909090
+
+	;sti
+	int	$0 // do interrupt
+intno = . -1;
+	cli;
+
+	// restore register
+	// preserve bx,es for protected mode
+	pop	%ds
+	addr32	movl %eax, (2f - LINKADDR)
+	movl	%ebx, %eax
+	addr32	movl %eax, (4f - LINKADDR)
+	movl	%es, %eax
+	addr32	movl %eax, (3f- LINKADDR)
+	addr32	movl (2f - LINKADDR), %eax
+
+	// save eflags to bh
+	movb	%ah, %bh
+	lahf
+	xchgb	%ah, %bh
+
+	// preserve ax for protected mode
+	addr32	movl %eax, (2f - LINKADDR)
+
+	real2prot
+
+	// movl $Leax, %eax
+	.byte	0xb8
+4:	.long	0x90909090
+	mov	%eax, BIOS_BX
+
+	// movl $Leax, %eax
+	.byte	0xb8
+3:	.long	0x90909090
+	mov	%eax, BIOS_ES
+
+	// movl $Leax, %eax
+	.byte	0xb8
+2:	.long	0x90909090
+
+	// pass BIOS return values back to caller
+	movl	%eax, 0xb*4(%esp)
+	movl	%ecx, 0xa*4(%esp)
+	movl	%edx, 0x9*4(%esp)
+	movb	%bh, 0xe*4(%esp)	// restore eflags
+
+	// save register into BIOSREG
+	.code32
+	movl	%eax, BIOS_AX
+	movl	%ecx, BIOS_CX
+	movl	%edx, BIOS_DX
+	movl	%ebp, BIOS_BP
+	movl	%esi, BIOS_SI
+	movl	%edi, BIOS_DI
+
+	// clear NT(Nested Task Flag: 14) flag in eflag
+	// if 1 : interrupting
+	pushf
+	pop	%eax
+	and	$0xffffbfff, %eax
+	push	%eax
+	popf
+
+	pop	%ds	
+	pop	%es
+	pop	%fs
+	pop	%gs
+	popa
+	iret
diff --git a/boot/ld.script b/boot/ld.script
index 95a3ec3..9792dca 100644
--- a/boot/ld.script
+++ b/boot/ld.script
@@ -1,27 +1,54 @@
-OUTPUT_FORMAT("elf32-i386", "elf32-i386", "elf32-i386")
-OUTPUT_ARCH(i386)
-
-PHDRS
+ PHDRS
 {
 	text PT_LOAD;
 }
 SECTIONS
 {
-	.text : {
-		KEEP(srt0.o(.text))
-		*(.text)
-	} :text
-	etext = .;
-	.data : { *(.data) } :text
-	.rodata : { *(.rodata) } :text
-	edata = .;
-	.bss : { *(.bss) } :text
-	ebss = .;
-    end = .;
-	/DISCARD/ : 
+  .text :
+  {
+    start = . ;
+    _start = . ;
+    __start = . ;
+    *(.text)
+    etext = . ;
+  } :text
+  .data :
+  {
+    __data_start__ = . ;
+    *(.data)
+    __data_end__ = . ;
+    __rdata_start__ = . ;
+    *(.rdata)
+    __rdata_end__ = . ;
+    *(.pdata)
+    *(.edata)
+  } :text
+  .bss :
+  {
+    edata = . ;
+    _edata = . ;
+    __edata = . ;
+    __bss_start__ = . ;
+    *(.bss)
+    __common_start__ = . ;
+    *(COMMON)
+    __bss_end__ = . ;
+    end = . ;
+    _end = . ;
+    __end = . ;
+  } :text
+  .stab :
+  {
+    *(.stab)
+  }
+  .stabstr :
+  {
+    *(.stabstr)
+  } :text
+  /DISCARD/ : 
     {
         *(.note.gnu.property)
         *(.comment)
     }
 }
- 
+
diff --git a/boot/print.c b/boot/print.c
new file mode 100644
index 0000000..6601606
--- /dev/null
+++ b/boot/print.c
@@ -0,0 +1,70 @@
+#include <u.h>
+#include "dat.h"
+#include "fn.h"
+
+#define TABWIDTH 8
+#define DEL '\177'
+
+static void conputc(int c);
+static int congetc(void);
+
+static int pos = 0;
+
+int
+getchar(void)
+{
+	int c;
+
+	c = congetc();	
+	if( c == '\r')
+		c = '\n';
+	if((c < ' ' && c != '\n') || c == DEL)
+		return c;
+	putchar(c);
+	return c;
+}
+
+void
+putchar(int c)
+{
+	switch(c){
+	case DEL:
+		conputc('\b');
+		conputc(' ');
+	case '\b':
+		conputc('\b');
+		if(pos)
+			--pos;
+		break;
+	case '\t':
+		do{
+			conputc(' ');
+		}while(++pos % TABWIDTH);
+		break;
+	case '\n':
+	case '\r':
+		conputc(c);
+		pos = 0;
+		break;
+	default:
+		conputc(c);
+		++pos;
+		break;
+	}	
+}
+
+static void
+conputc(int c)
+{
+	if(c){
+		condev.putc(condev.dev, c);
+		if(c == '\n')
+			condev.putc(condev.dev, '\r');
+	}	
+}
+
+static int 
+congetc(void)
+{
+	return condev.getc(condev.dev);
+}
diff --git a/boot/srt0.S b/boot/srt0.S
index a99fe11..16110f5 100644
--- a/boot/srt0.S
+++ b/boot/srt0.S
@@ -1,13 +1,12 @@
 .file "srt0.S"
 
-#define BOOTSTACK 0xfffc
-#define	CR0_PE	0x00000001	/* Protected mode Enable */
+#include "def.h"
 
 	.globl	end
 	.globl	edata
 	.globl	Gdtr
 	.globl	boot
-	.globl	pmm_init
+	.globl	pmode_init
 
 	.text
 	.code16
@@ -20,14 +19,16 @@ _start:
 
 1:
 	popl	%edx
+// load GDT
 	cli
 	pushl	%cs
 	popl	%ds
 	addr32	data32 lgdt	(Gdtr - LINKADDR)
 	movl	%cr0, %eax
+// enable protected mode
 	orl	$CR0_PE, %eax
 	data32	movl %eax, %cr0
-	data32	ljmp $8, $1f
+	data32	ljmp $S32TEXT, $1f
 
 1:
 	.code32
@@ -37,7 +38,7 @@ _start:
 	mov	%ax, %es
 	mov	%ax, %fs
 	mov	%ax, %gs
-	movl	$BOOTSTACK, %esp
+	movl	$BOOTSTACKOFF, %esp
 	pushl	%edx
 
 	// fill 0 .bss
@@ -48,5 +49,5 @@ _start:
 	cld
 	rep;	stosb
 
-	call	pmm_init
+	call	pmode_init
 	call	boot
diff --git a/btld_conf.h b/btld_conf.h
new file mode 100644
index 0000000..1f2a34e
--- /dev/null
+++ b/btld_conf.h
@@ -0,0 +1,12 @@
+#define FAT16_MAX (0x40000)
+#define	DOSPTYP_UNUSED 0x00
+#define	DOSPTYP_FAT16 0x06
+#define DOSPARTOFF 446
+#define DOSDISKOFF 444
+#define NDOSPART 4
+#define DOSACTIVE 0x80
+#define	DOSMBR_SIGNATURE 0xAA55
+#define	BOOT_MAGIC	0xf1abde3f
+#define DOSMBR_SIGNATURE_OFF 0x1fe
+
+#define PARTSZ	16
\ No newline at end of file
diff --git a/dat.h b/btld_disk.h
similarity index 81%
rename from dat.h
rename to btld_disk.h
index 85769d7..98d479a 100644
--- a/dat.h
+++ b/btld_disk.h
@@ -1,21 +1,3 @@
-#include <fcntl.h>
-#include <unistd.h>
-#include <stdint.h>
-#include <string.h>
-#include <sys/ioctl.h>
-#include <sys/stat.h>
-#include <limits.h>
-#include <assert.h>
-#include "def.h"
-
-#define elem(x) ((int)(sizeof(x)/sizeof((x)[0])))
-
-typedef uint8_t u8;
-typedef uint16_t u16;
-typedef uint32_t u32;
-typedef uint64_t u64;
-typedef unsigned int uint;
-
 typedef struct{
 	u64 cyl;
 	u64 head;
diff --git a/def.h b/def.h
deleted file mode 100644
index 6dbd9a7..0000000
--- a/def.h
+++ /dev/null
@@ -1,22 +0,0 @@
-#define FAT16_MAX (0x40000)
-#define	DOSPTYP_UNUSED 0x00
-#define	DOSPTYP_FAT16 0x06
-#define DOSPARTOFF 446
-#define DOSDISKOFF 444
-#define NDOSPART 4
-#define DOSACTIVE 0x80
-#define	DOSMBR_SIGNATURE 0xAA55
-#define	BOOT_MAGIC	0xf1abde3f
-#define DOSMBR_SIGNATURE_OFF 0x1fe
-
-#define BOOTSEG	0x7c0
-#define BOOTRELOCSEG 0x7a0
-#define MBRSTACKOFF 0xfffc
-#define PARTSZ	16
-#define LOADSEG (LOADADDR >> 4)
-#define FATSEG 0x07e0	/* FAT table segment */
-
-#define BOOTSTACKOFF ((BOOTSEG << 4) - 4)  /* stack starts here, grows down */
-#define LFMAGIC 0x464c  /* LFMAGIC (last two bytes of \7fELF) */
-#define ELFMAGIC 0x464c457f  /* ELFMAGIC ("\7fELF") */
-
diff --git a/installboot/Makefile b/installboot/Makefile
index f54fed8..ce1d9e7 100644
--- a/installboot/Makefile
+++ b/installboot/Makefile
@@ -1,15 +1,17 @@
-PROG=installboot
-SRCS=$(wildcard *.c)
-OBJS=$(SRCS:.c=.o)
+SDIR ?= ../
+BDIR ?= ./
+
+PROG = installboot
+SRCS = installboot.c
+OBJS = installboot.o
 
 CFLAGS = -g -Wall -Werror
-CPPFLAGS = -I $(IDIR)
+CPPFLAGS = -I $(SDIR)
 
 ${PROG}: $(OBJS)
-	$(CC) $(CFLAGS) -o $(BDIR)/$(PROG) $^
-	cp filecopy.sh $(BDIR)
+	$(CC) $(CFLAGS) -o $(BDIR)/$(PROG) $(OBJS)
 
-$(OBJS): ../dat.h
+$(OBJS): $(SDIR)/u.h $(SDIR)/btld_conf.h $(SDIR)/btld_disk.h elf32.h
 
 clean:
-	rm -rf $(PROG) *.o
+	rm -rf $(PROG) $(OBJS)
diff --git a/installboot/installboot.c b/installboot/installboot.c
index 13875eb..5f635a9 100644
--- a/installboot/installboot.c
+++ b/installboot/installboot.c
@@ -1,12 +1,18 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <ctype.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/stat.h>
+#include <sys/ioctl.h>
 #include <sys/mount.h>
-#include <sys/sysmacros.h>
+#include <fcntl.h>
 #include <sys/wait.h>
 #include <errno.h>
 #include <assert.h>
-#include "dat.h"
+#include <u.h>
+#include "btld_conf.h"
+#include "btld_disk.h"
 #include "elf32.h"
 
 static char *devpath;
@@ -39,21 +45,21 @@ static struct{
 	{"and_magic", 2},
 };
 
-void
+static void
 usage(void)
 {
 	fprintf(stderr, "usgae: ./installboot device [bin]\n");
 	exit(1);
 }
 
-int
+static int
 streq(char *a, char *b)
 {
 	int la = strlen(a);
 	return la==strlen(b) && memcmp(a, b, la)==0;
 }
 
-void
+static void
 loadelf(char *fname)
 {
 	int fd;
@@ -96,7 +102,7 @@ found:
 	close(fd);
 }
 
-void
+static void
 symset(char *name, u32 val)
 {
 	for(int i = 0; i < elem(syms); ++i){
@@ -108,7 +114,7 @@ symset(char *name, u32 val)
 	assert(0 && "symbol not exist");
 }
 
-uint
+static uint
 tou32(u8 *str, int i)
 {
 	uint x = 0;
@@ -120,7 +126,7 @@ tou32(u8 *str, int i)
 	return x;
 }
 
-u16
+static u16
 exponent(u16 x)
 {
 	switch(x){
@@ -138,7 +144,7 @@ exponent(u16 x)
 	}
 }
 
-void
+static void
 emit(u64 off)
 {
 	for(int i = 0; i < elem(syms); ++i){
@@ -161,7 +167,7 @@ emit(u64 off)
 			sizeof(btcode)-0x3c);
 }
 
-void
+static void
 setbootparam(int ino, int off, int sec)
 {
 	u8 buf[512];
@@ -189,18 +195,7 @@ setbootparam(int ino, int off, int sec)
 	symset("and_magic", bps-1);
 }
 
-void
-catpath(char *dst, char *s1, char *s2)
-{
-	while(*s1)
-		*dst++ = *s1++;
-	*dst++ = '/';
-	while(*s2)
-		*dst++ = *s2++;
-	*dst = '\0';
-}
-
-void
+static void
 install(void)
 {
 	char *args[] = {shpath, devpath, NULL};
diff --git a/installmbr/Makefile b/installmbr/Makefile
index 982e7d7..84e608a 100644
--- a/installmbr/Makefile
+++ b/installmbr/Makefile
@@ -1,15 +1,17 @@
-PROG=installmbr
-SRCS=$(wildcard *.c)
-OBJS=$(SRCS:.c=.o)
+SDIR ?= ../
+BDIR ?= ./
 
-CFLAGS = -g
-CPPFLAGS = -I $(IDIR)
+PROG = installmbr
+SRCS = installmbr.c
+OBJS = installmbr.o
+
+CFLAGS = -g -Wall -Werror
+CPPFLAGS = -I $(SDIR)
 
 ${PROG}: $(OBJS)
-	@rm -f $(PROG)
-	$(CC) $(CFLAGS) -o $(BDIR)/$(PROG) $^ 
+	$(CC) $(CFLAGS) -o $(BDIR)/$(PROG) $(OBJS)
 
-$(OBJS): ../dat.h
+$(OBJS): $(SDIR)/u.h $(SDIR)/btld_conf.h $(SDIR)/btld_disk.h
 
 clean:
-	rm -rf $(PROG) $(OBJS)
+	rm -f $(PROG) $(OBJS)
diff --git a/installmbr/installmbr.c b/installmbr/installmbr.c
index d32b10e..40c5c15 100644
--- a/installmbr/installmbr.c
+++ b/installmbr/installmbr.c
@@ -1,17 +1,24 @@
+#include <stdint.h>
+#include <string.h>
 #include <fcntl.h>
 #include <unistd.h>
 #include <linux/fs.h>
+#include <sys/ioctl.h>
+#include <sys/stat.h>
 #include <stdio.h>
 #include <limits.h>
 #include <endian.h>
 #include <stdlib.h>
-#include "dat.h"
+#include <assert.h>
+#include <u.h>
+#include "btld_conf.h"
+#include "btld_disk.h"
 
 static char *binpath = "build/mbr";
 static char bootcode[DOSPARTOFF];
 static Disk dsk;
 
-void
+static void
 usage(void)
 {
 	fprintf(stderr, "usage: ./mkmbr device\n");
@@ -34,7 +41,7 @@ secwrite(void *buf, u64 sec, u32 cnt, Disk *dsk)
 	return wc;
 }
 
-char*
+static char*
 secread(u64 sec, u32 cnt, Disk *dsk)
 {
 	char *buf;
@@ -53,7 +60,7 @@ secread(u64 sec, u32 cnt, Disk *dsk)
 	return buf;
 }
 
-int
+static int
 diskwrite(void *buf, u64 sec, u64 sz, Disk *dsk)
 {
 	char *secbuf;
@@ -68,7 +75,7 @@ diskwrite(void *buf, u64 sec, u64 sz, Disk *dsk)
 	return wc;
 }
 
-Part
+static Part
 dospt2pt(DOSpart dpt, u64 self, u64 ext)
 {
 	Part pt={0,};
@@ -90,7 +97,7 @@ dospt2pt(DOSpart dpt, u64 self, u64 ext)
 // H = (LBA / SPT) % HPC
 // S = (LBA / SPT) + 1
 
-CHS
+static CHS
 lba2chs(u64 lba, u64 spt, u64 hpc)
 {
 	CHS c = {0,};
@@ -101,7 +108,7 @@ lba2chs(u64 lba, u64 spt, u64 hpc)
 	return c;
 }
 
-CHS
+static CHS
 lba2chsbeg(Part pt)
 {
 	if(pt.ns == 0 || pt.id == DOSPTYP_UNUSED)
@@ -109,7 +116,7 @@ lba2chsbeg(Part pt)
 	return lba2chs(pt.bs, dsk.spt, dsk.hpc);
 }
 
-CHS
+static CHS
 lba2chsend(Part pt)
 {
 	if(pt.ns == 0 || pt.id == DOSPTYP_UNUSED)
@@ -117,7 +124,7 @@ lba2chsend(Part pt)
 	return lba2chs(pt.bs+pt.ns-1, dsk.spt, dsk.hpc);
 }
 
-CHS
+static CHS
 chsnorm(u8 id, CHS c)
 {
 	if(c.head > 254 || c.sec > 63 || c.cyl > 1023){
@@ -131,7 +138,7 @@ chsnorm(u8 id, CHS c)
 	return c;
 }
 
-DOSpart
+static DOSpart
 pt2dospt(Part pt, u64 self, u64 ext)
 {
 	DOSpart d={0,};
@@ -158,7 +165,7 @@ pt2dospt(Part pt, u64 self, u64 ext)
 	return d;
 }
 
-DOSmbr
+static DOSmbr
 mbr2dosmbr(MBR m)
 {
 	DOSmbr d={0,};
@@ -174,7 +181,7 @@ mbr2dosmbr(MBR m)
 	return d;
 }
 
-MBR
+static MBR
 mbrinit(void)
 {
 	MBR m = {0,};
@@ -198,7 +205,7 @@ mbrinit(void)
 	return m;
 }
 
-int
+static int
 mbrwrite(MBR m)
 {
 	DOSmbr d;
@@ -209,7 +216,7 @@ mbrwrite(MBR m)
 	return wc; 
 }
 
-void
+static void
 read512(char *path)
 {
 	int fd;
diff --git a/mbr/Makefile b/mbr/Makefile
index 1132e93..934945d 100644
--- a/mbr/Makefile
+++ b/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)
\ No newline at end of file
diff --git a/mbr/mbr.S b/mbr/mbr.S
index bdc08aa..faa204f 100644
--- a/mbr/mbr.S
+++ b/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
 
diff --git a/u.h b/u.h
new file mode 100644
index 0000000..6be17ee
--- /dev/null
+++ b/u.h
@@ -0,0 +1,21 @@
+#define elem(x) ((int)(sizeof(x)/sizeof((x)[0])))
+#define nil		((void*)0)
+
+typedef	unsigned short	ushort;
+typedef	unsigned char	uchar;
+typedef unsigned long	ulong;
+typedef unsigned int	uint;
+typedef signed char	schar;
+typedef	long long	vlong;
+typedef	unsigned long long uvlong;
+typedef long		iptr;
+typedef unsigned long	uptr;
+typedef unsigned long	usize;
+typedef unsigned char	u8;
+typedef unsigned short	u16;
+typedef unsigned int	u32;
+typedef unsigned long long u64;
+typedef signed char i8;
+typedef signed short i16;
+typedef signed int i32;
+typedef signed long long i64;
\ No newline at end of file