Build: Remove grub from default build process

This removes grub and all the loopback device business from the default
build process. Running grub takes about a second, and it turns out it's
inconsistently packaged in different distributions, which has led to
at least one confusing issue so far (grub-install vs grub2-install).
Removing it from the basic path will make it easier for people to try
Serenity out.

There are now two scripts that can be used to build a disk image:

1. `build-image-grub.sh` - this will build an image suitable for writing
   to the IDE hard drive of a physical machine, complete with a partition
   table and bootloader. This can be run in qemu with the `qgrub` target
   for the `run` script.
2. `build-image-qemu.sh` - this is a simpler script which creates a bare
   filesystem image rather than a full MBR disk.

Both of these call out to `build-root-filesystem.sh` to do most of the
work setting up... the root filesystem.

For completeness' sake, I've retained the `sync.sh` script as a simple
forwarding to `build-image-qemu.sh`.

This relies on the functionality from #194 and #195. #195 allows us to
use `/dev/hda` as the root device when nothing else is specified, and #194
works around a strange feature of qemu that appends a space to the kernel
command line.

1 files changed, 87 insertions, 0 deletions

diff --git a/Kernel/build-image-grub.sh b/Kernel/build-image-grub.sh
new file mode 100755
index 0000000000..dc4ca60966
--- /dev/null
+++ b/Kernel/build-image-grub.sh
@@ -0,0 +1,87 @@
+#!/bin/bash
+
+set -e
+
+die() {
+    echo "die: $@"
+    exit 1
+}
+
+if [ $(id -u) != 0 ]; then
+    die "this script needs to run as root"
+fi
+
+grub=$(which grub-install 2>/dev/null) || true
+if [[ -z "$grub" ]]; then
+    grub=$(which grub2-install 2>/dev/null) || true
+fi
+if [ -z "$grub" ]; then
+    echo "can't find a grub-install or grub2-install binary, oh no"
+    exit 1
+fi
+echo "using grub-install at ${grub}"
+
+echo "setting up disk image..."
+dd if=/dev/zero of=_disk_image bs=1M count=${DISK_SIZE:-500} status=none || die "couldn't create disk image"
+chown 1000:1000 _disk_image || die "couldn't adjust permissions on disk image"
+echo "done"
+
+echo -n "creating loopback device... "
+dev=$(losetup --find --partscan --show _disk_image)
+if [ -z $dev ]; then
+    die "couldn't mount loopback device"
+fi
+echo "loopback device is at ${dev}"
+
+cleanup() {
+    if [ -d mnt ]; then
+        echo -n "unmounting filesystem... "
+        umount mnt || ( sleep 1 && sync && umount mnt )
+        rm -rf mnt
+        echo "done"
+    fi
+
+    if [ -e ${dev} ]; then
+        echo -n "cleaning up loopback device... "
+        losetup -d ${dev}
+        echo "done"
+    fi
+}
+trap cleanup EXIT
+
+echo -n "creating partition table... "
+parted -s ${dev} mklabel msdos mkpart primary ext2 32k 100% -a minimal set 1 boot on || die "couldn't partition disk"
+echo "done"
+
+echo -n "destroying old filesystem... "
+dd if=/dev/zero of=${dev}p1 bs=1M count=1 status=none || die "couldn't destroy old filesystem"
+echo "done"
+
+echo -n "creating new filesystem... "
+mke2fs -q -I 128 ${dev}p1 || die "couldn't create filesystem"
+echo "done"
+
+echo -n "mounting filesystem... "
+mkdir -p mnt
+mount ${dev}p1 mnt/ || die "couldn't mount filesystem"
+echo "done"
+
+./build-root-filesystem.sh
+
+echo -n "creating /boot... "
+mkdir -p mnt/boot
+echo "done"
+
+echo "installing grub using $grub..."
+$grub --boot-directory=mnt/boot --target=i386-pc --modules="ext2 part_msdos" ${dev}
+
+if [ -d mnt/boot/grub2 ]; then
+    cp grub.cfg mnt/boot/grub2/grub.cfg
+else
+    cp grub.cfg mnt/boot/grub/grub.cfg
+fi
+echo "done"
+
+echo -n "installing kernel in /boot... "
+cp kernel mnt/boot
+echo "done"