GRUB always enters a rescue shell.

[Aruna Hewapathirane]

Hello Hao,

On Thu, Jul 13, 2017 at 4:39 AM, Hao Lee <haolee.swjtu at gmail.com> wrote:

> Hi,
>
> I encounter a problem when making a bootable disk image because GRUB
> always enters a
> rescue shell.
>
> I want to create a disk image and install GRUB 2 on it and then use
> Bochs to run it. The steps are as follows.
>
> System Environment:
> OS: Fedora 25 x86
> GRUB version: grub2-install (GRUB) 2.02~beta3
> Bochs version: 2.6.9
>
> 1. Create a empty disk image.
>
> dd if=/dev/zero of=hd.img bs=$((16*63*512)) count=100
>
> 2. Create a primary partition.
>
> fdisk -u -C100 -S63 -H16 hd.img
>
> The partition  table is:
> Device     Boot Start    End Sectors  Size Id Type
> hd.img1          2048 100799   98752 48.2M 83 Linux
>
>
Hint: when you run: /usr/bin/file hd.img what do you see ?



> 3. Attach the whole image to /dev/loop0 and attach the first partition
> to /dev/loop1
>
> sudo losetup /dev/loop0 hd.img
> sudo losetup -o $((2048*512)) /dev/loop1 hd.img
>
> 4. Format the first partition to ext4 and mount it to /mnt/
>
> sudo mkfs.ext4 /dev/loop1
> sudo mount -t ext4 /dev/loop1 /mnt
>
> 5. Create GRUB directory.
>
> sudo mkdir -p /mnt/boot/grub2
>
> 6. Install GRUB 2
>
> sudo grub2-install --boot-directory=/mnt/boot /dev/loop0
>


2nd hint: ask yourself does the grub *core.img" have the required module
built-in by default ?


>
> 7. Start Bochs.
>
> bochs -f test.bxrc
>
> These steps are straight and simple. However, GRUB always enters a
> rescue shell instead of entering normal mode.
> When I use the set and ls command to show more information, I can only
> see (hd0) and the first partition (hd0,1) is disappeared. The screen
> output is as follows:
> ----------------------------------------------------
> Bochs BIOS - build: 02/16/17
> ata0 master: Generic 1234 ATA-6 Hard-Disk (  49 MBytes)
> Press F12 for boot menu.
> Booting from Hard Disk...
> .
> error: no such device: c5b2c483-70c2-4212-840b-da5f965d0555.
> error: unknown filesystem.
> Entering rescue mode...
> grub rescue> set
> prefix=(hd0)/boot/grub2
> root=hd0
> grub rescue> ls
> (hd0)
> grub rescue>
> ----------------------------------------------------
>
> Could someone help me out? Many thanks!
>

Yes *someone* can and will help you. Please watch till the very end. You
will not be disappointed :)

https://youtu.be/6oqTu8utMe4

Good luck and hope this helps - Aruna


>
> Regards,
> Hao Lee
>
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> Kernelnewbies mailing list
> Kernelnewbies at kernelnewbies.org
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>
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