On 21.02.2022 01:53, David Ventura wrote: > Hi > I'm trying to boot grub on a BIOS/GPT combination and am currently stuck. > I've created a test disk image with the following GPT partition (and > protective MBR): > > > Found valid GPT with protective MBR; using GPT. > Disk hdd-grub.raw: 131072 sectors, 64.0 MiB > Sector size (logical): 512 bytes > Disk identifier (GUID): 488005E7-D3AF-4B71-AEE6-F54B497A63FC > Partition table holds up to 128 entries > Main partition table begins at sector 2 and ends at sector 33 > First usable sector is 34, last usable sector is 131038 > Partitions will be aligned on 2048-sector boundaries > Total free space is 2014 sectors (1007.0 KiB) > > Number Start (sector) End (sector) Size Code Name > 1 2048 4095 1024.0 KiB EF02 BIOS boot partition > 2 4096 65535 30.0 MiB EF00 EFI system partition > 3 65536 131038 32.0 MiB 8300 Linux filesystem > > On this disk image, I've applied the boot.img MBR like so: > > dd if=/usr/lib/grub/i386-pc/boot.img of=hdd-grub.raw bs=440 > count=1 conv=notrunc > which successfully shows a "GRUB" prompt on BIOS. > > The only thing I've done after this, is to apply the core.img on the > exact BIOS boot partition offset: > > dd if=core.img of=hdd-grub.raw bs=512 seek=2048 conv=notrunc > > However, nothing different happens (the only thing I see is, still, > "GRUB" and a flashing cursor). > To be clear, I am _not_ seeing the emergency shell. > > The core image I've generated with this command: > grub-mkimage -O i386-pc -o ./core.img -p '(hd0,gpt3)/boot/grub' > biosdisk part_msdos xfs part_gpt > > I've tried embedding an early config and actually populating > (hd0,gpt3)/boot/grub/grub.cfg out of desperation but that did not > help. > > What am I doing wrong? >
You do not use grub-install. core.img location is stored in both boot.img by grub.install. What you see is boot.img which attempts to load and execute garbage so system hangs.
