freebsd-src/sbin/sysinstall/mbr.c

/*
 * Copyright (c) 1994, Paul Richards.
 *
 * All rights reserved.
 *
 * This software may be used, modified, copied, distributed, and
 * sold, in both source and binary form provided that the above
 * copyright and these terms are retained, verbatim, as the first
 * lines of this file.  Under no circumstances is the author
 * responsible for the proper functioning of this software, nor does
 * the author assume any responsibility for damages incurred with
 * its use.
 */

#include <stdio.h>
#include <unistd.h>
#include <dialog.h>
#include <fcntl.h>

#include <sys/types.h>
#include <sys/disklabel.h>
#include <sys/uio.h>

#include "mbr.h"
#include "sysinstall.h"

extern struct mbr *mbr;
extern int inst_part;
extern int whole_disk;

struct part_type part_types[] = PARTITION_TYPES

char *
part_type(int type)
{
	int num_types = (sizeof(part_types)/sizeof(struct part_type));
	int next_type = 0;
	struct part_type *ptr = part_types;

	while (next_type < num_types) {
		if(ptr->type == type)
			return(ptr->name);
		ptr++;
		next_type++;
	}
	return("Uknown");
}

int
read_mbr(int fd, struct mbr *mbr)
{
	if (lseek(fd, 0, SEEK_SET) == -1) {
		sprintf(errmsg, "Couldn't seek for master boot record read\n");
		return(-1);
	}
	if (read(fd, &(mbr->bootcode), MBRSIZE) == -1) {
		sprintf(errmsg, "Failed to read master boot record\n");
		return(-1);
	}
	/* Validate the master boot record */
	if (mbr->magic != MBR_MAGIC) {
		sprintf(errmsg, "Master boot record is invalid\n");
		return(-1);
	}
	return(0);
}

int
write_mbr(int fd, struct mbr *mbr)
{
	if (lseek(fd, 0, SEEK_SET) == -1) {
		sprintf(errmsg, "Couldn't seek for master boot record write\n");
		return(-1);
	}

	if (enable_label(fd) == -1)
		return(-1);

	if (write(fd, mbr->bootcode, MBRSIZE) == -1) {
		sprintf(errmsg, "Failed to write master boot record\n");
		return(-1);
	}

	if(disable_label(fd) == -1)
		return(-1);

	return(0);
}

void
show_mbr(struct mbr *mbr)
{
	int i, j, key = 0;
	int x, y;
	WINDOW *window;

	window = newwin(LINES, COLS, 0, 0);
	keypad(window, TRUE);

	draw_box(window, 0, 0, LINES - 1, COLS - 1,
				COLOR_PAIR(COLOR_YELLOW), COLOR_PAIR(COLOR_BLUE));

	for (i=0; i<NDOSPART/2; i++) {
		for (j=0; j<NDOSPART/2; j++) {
			x = (j * 38) + 3;
			y = (i * 11) + 2;
			mvwprintw(window, y, x, "Partition %d: flags = %x",
					  (i*2)+j, mbr->dospart[(i*2)+j].dp_flag);
			mvwprintw(window, y+1, x, "Starting at (C%d, H%d, S%d)",
					  mbr->dospart[(i*2)+j].dp_scyl,
					  mbr->dospart[(i*2)+j].dp_shd,
					  mbr->dospart[(i*2)+j].dp_ssect);
			mvwprintw(window, y+2, x, "Type: %s (%x)",
					  part_type(mbr->dospart[(i*2)+j].dp_typ),
		           mbr->dospart[(i*2)+j].dp_typ);
			mvwprintw(window, y+3, x, "Ending at (C%d, H%d, S%d)",
					  mbr->dospart[(i*2)+j].dp_ecyl,
					  mbr->dospart[(i*2)+j].dp_ehd,
					  mbr->dospart[(i*2)+j].dp_esect);
			mvwprintw(window, y+4, x, "Absolute start sector %ld",
					  mbr->dospart[(i*2)+j].dp_start);
			mvwprintw(window, y+5, x, "Size (in sectors) %ld", mbr->dospart[(i*2)+j].dp_size);
		}
	}
	refresh();

	while (key != '\n')
		key = wgetch(window);

	delwin(window);
	dialog_clear();
}

int
clear_mbr(struct mbr *mbr, char *bootcode)
{
	int i;
   int fd;

	/*
	 * If installing to the whole disk
	 * then clobber any existing bootcode.
	 */

	sprintf(scratch, "\nLoading MBR code from %s\n", bootcode);
	dialog_msgbox(TITLE, scratch, 5, 60, 0);
	fd = open(bootcode, O_RDONLY);
	if (fd < 0) {
		sprintf(errmsg, "Couldn't open boot file %s\n", bootcode);
		return(-1);
	}  

	if (read(fd, mbr->bootcode, MBRSIZE) < 0) {
		sprintf(errmsg, "Couldn't read from boot file %s\n", bootcode);
		return(-1);
	}
			
	if (close(fd) == -1) {
		sprintf(errmsg, "Couldn't close boot file %s\n", bootcode);
		return(-1);
	}  

	/* Create an empty partition table */

	for (i=0; i < NDOSPART; i++) {
		mbr->dospart[i].dp_flag = 0;
		mbr->dospart[i].dp_shd = 0;
		mbr->dospart[i].dp_ssect = 0;
		mbr->dospart[i].dp_scyl = 0;
		mbr->dospart[i].dp_typ = 0;
		mbr->dospart[i].dp_ehd = 0;
		mbr->dospart[i].dp_esect = 0;
		mbr->dospart[i].dp_ecyl = 0;
		mbr->dospart[i].dp_start = 0;
		mbr->dospart[i].dp_size = 0;
	}

	mbr->magic = MBR_MAGIC;

	dialog_clear();
	return(0);
}

int
build_mbr(struct mbr *mbr, char *bootcode, struct disklabel *lb)
{
	int i;
	struct dos_partition *dp = &mbr->dospart[inst_part];

	if (whole_disk) {
		/* Install to entire disk */
		if (clear_mbr(mbr, bootcode) == -1)
			return(-1);
		dp->dp_scyl = 0;
		dp->dp_shd = 1;
		dp->dp_ssect = 1;
		dp->dp_ecyl = lb->d_ncylinders - 1;
		dp->dp_ehd = lb->d_ntracks - 1;
		dp->dp_esect = lb->d_nsectors;
		dp->dp_start = (dp->dp_scyl * lb->d_ntracks * lb->d_nsectors) + 
						  (dp->dp_shd * lb->d_nsectors) +
						  dp->dp_ssect - 1;
		dp->dp_size = (lb->d_nsectors * lb->d_ntracks * lb->d_ncylinders) - dp->dp_start;
	}

	/* Validate partition - XXX need to spend some time making this robust */
	if (!dp->dp_start) {
		strcpy(errmsg, "The start address of the selected partition is 0\n");
		return(-1);
	}

	/* Set partition type to FreeBSD and make it the only active partition */

	for (i=0; i < NDOSPART; i++)
		mbr->dospart[i].dp_flag &= ~ACTIVE;
	dp->dp_typ = DOSPTYP_386BSD;
	dp->dp_flag = ACTIVE;

	return(0);
}

void
edit_mbr(struct mbr *mbr, struct disklabel *label)
{

	dialog_msgbox("DOS partition table editor", 
		"This editor is still under construction :-)", 10, 75, 1);
	show_mbr(mbr);
}