generate-fat.sh revision 293425 
1#!/bin/sh
2
3# This script generates the dummy FAT filesystem used for the EFI boot
4# blocks. It uses newfs_msdos to generate a template filesystem with the
5# relevant interesting files. These are then found by grep, and the offsets
6# written to a Makefile snippet.
7#
8# Because it requires root, and because it is overkill, we do not
9# do this as part of the normal build. If makefs(8) grows workable FAT
10# support, this should be revisited.
11
12# $FreeBSD: head/sys/boot/efi/boot1/generate-fat.sh 293425 2016-01-08 16:37:22Z emaste $
13
14FAT_SIZE=1600 			#Size in 512-byte blocks of the produced image
15
16BOOT1_SIZE=128k
17
18#
19# Known filenames
20# amd64:   BOOTx64.efi
21# arm64:   BOOTaa64.efi
22# arm:     BOOTarm.efi
23# i386:    BOOTia32.efi
24#
25if [ -z "$2" ]; then
26	echo "Usage: $0 arch boot-filename"
27	exit 1
28fi
29
30ARCH=$1
31FILENAME=$2
32
33# Generate 800K FAT image
34OUTPUT_FILE=fat-${ARCH}.tmpl
35
36dd if=/dev/zero of=$OUTPUT_FILE bs=512 count=$FAT_SIZE
37DEVICE=`mdconfig -a -f $OUTPUT_FILE`
38newfs_msdos -F 12 -L EFI $DEVICE
39mkdir stub
40mount -t msdosfs /dev/$DEVICE stub
41
42# Create and bless a directory for the boot loader
43mkdir -p stub/efi/boot
44
45# Make a dummy file for boot1
46echo 'Boot1 START' | dd of=stub/efi/boot/$FILENAME cbs=$BOOT1_SIZE count=1 conv=block
47
48umount stub
49mdconfig -d -u $DEVICE
50rmdir stub
51
52# Locate the offset of the fake file
53BOOT1_OFFSET=$(hd $OUTPUT_FILE | grep 'Boot1 START' | cut -f 1 -d ' ')
54
55# Convert to number of blocks
56BOOT1_OFFSET=$(echo 0x$BOOT1_OFFSET | awk '{printf("%x\n",$1/512);}')
57
58# Record maximum boot1 size in bytes
59case $BOOT1_SIZE in
60*k)
61	BOOT1_MAXSIZE=$(expr ${BOOT1_SIZE%k} '*' 1024)
62	;;
63*)
64	BOOT1_MAXSIZE=$BOOT1_SIZE
65	;;
66esac
67
68echo '# This file autogenerated by generate-fat.sh - DO NOT EDIT' > Makefile.fat
69echo '# $FreeBSD: head/sys/boot/efi/boot1/generate-fat.sh 293425 2016-01-08 16:37:22Z emaste $' >> Makefile.fat
70echo "BOOT1_OFFSET=0x$BOOT1_OFFSET" >> Makefile.fat
71echo "BOOT1_MAXSIZE=$BOOT1_MAXSIZE" >> Makefile.fat
72
73bzip2 $OUTPUT_FILE
74echo 'FAT template boot filesystem created by generate-fat.sh' > $OUTPUT_FILE.bz2.uu
75echo 'DO NOT EDIT' >> $OUTPUT_FILE.bz2.uu
76echo '$FreeBSD: head/sys/boot/efi/boot1/generate-fat.sh 293425 2016-01-08 16:37:22Z emaste $' >> $OUTPUT_FILE.bz2.uu
77
78uuencode $OUTPUT_FILE.bz2 $OUTPUT_FILE.bz2 >> $OUTPUT_FILE.bz2.uu
79rm $OUTPUT_FILE.bz2
80
81