The mkfs.ext2 heuristics select the "small" ext2 usage type, which does
not fit well with GiB-sized pen drives. For example, the block size is
just 1024 bytes compared to 4096 for "default". Therefore, we enforce
the default usage type as this fits our use case of dumping the image to
USB sticks better.
This provides bootable disk images for x86 platforms via
! RUN_OPT="--target disk"
The resulting disk image contains one ext2 partition with binaries from
the GRUB2 boot loader and the run scenario. The default disk size fits
all binaries, but is configurable via
! --disk-size <size in MiB>
in RUN_OPT.
The feature depends on an grub2-head.img, which is part of the commit,
but may also be generated by executing tool/create_grub2. The script
generates a disk image prepared for one partition, which contains files
for GRUB2. All image preparation steps that need superuser privileges
are conducted by this script.
The final step of writing the entire image to a disk must be executed
later by
sudo dd if=<image file> of=<device> bs=8M conv=fsync
Fixes#1203.
Alexander Boettcher
Christian Helmuth