Booting from HDD using a custom grub menu

retrorimmer

I know the distro is intended to be boot and run from a USB/SDCard but I was wanting to setup
a dual boot system running alongside a Windows XP installation.

I've been experimenting with HDD installs and dual booting from Windows XP using the boot.ini.
As I don't much about the boot stages involved when booting the batocera image from a USB drive.
I'm struggling to find a 100% working solution in booting the /boot/batocera (squashed image?)
directly from HDD using a custom grub boot menu.

I have Windows XP installed on a 8GB FAT32 disk and copied the contents of the batocera.xxx.img
to the root drive C:\ along with recalbox-boot.conf at the root.

Next I booted a linux box and obtained the mbr from the batocera.xxx.img using the command:
dd if=/dev/sdx/batocera.xxx.img of=/dev/sdx/mbr.bin count=1 bs=512

I copied the 512 byte mbr.img to the Windows XP drive C:\ and added this to boot.ini
[operating systems]
multi(0)disk(0)rdisk(0)partition(5)\WINDOWS="Microsoft Windows XP Professional" /NOEXECUTE=OPTIN /FASTDETECT
C:\mbr.bin="Batocera RecalBox"

The above steps result in a black screen with just GRUB _
A 1st failed attempt!

My next step involved using a Super Grub2 disk (https://www.supergrubdisk.org/)
This time the Grub 2 Menu found the Batocera boot folder and associated grub.cfg and
sucessfully booted the /boot/batocera

Not so far into the boot process the Batocera splash screen shown for a few seconds the
went to a black screen. I accessed the console on tty3 to find the following messages:

xauth: file /recalbox/share/system/.Xauthority does not exist
done
/usr/bin/recallog: line 8: echo: write error: No space left on device
/usr/bin/recallog: line 8: echo: write error: No space left on device
INIT: Entering runlevel: 3
PLAY AGAIN
BATOCERA login:

I was able to login using root:linux
Seems that the next stage after booting where the share drive is mounted, this has failed
somewhere along the boot process and not been created. There is enough free space 10GB
and I even created an empty 2GB partition.

I'm puzzled why the batocera image can be written to an empty USB drive and it will successful
mount and partition itself. Also does the boot image use Grub or Grub2 ? and how is the
share partition setup when the image is first booted ?

retrorimmer

SUCCESS! by much searching through the squashed file system I found a script called
\recalbox\scripts\recalbox-part.sh

I ran the script as follows to find out the partitions being used
\recalbox\scripts\recalbox-part.sh boot
\recalbox\scripts\recalbox-part.sh share_internal

Turns out the share_internal partition was pointing to sda2 on the same drive of Windows XP, which was a 1MB partition created by Windows XP. Sure enough, not enough space for the shared files.

As I wanted to store all shared files (roms etc..) on a seperate disk or usb disk, I had to edit the
recalbox-boot.conf file which was on the root of Drive C: and change the sharedevice to ANYEXTERNAL

sharedevice=ANYEXTERNAL
#sharedevice=INTERNAL
#splashsound=false
#nvidia-driver=true

When I rebooted the emulation interface started and all was working as normal.
The shared drive had to be formatted as Ext4 as using a shared FAT32 drive
results in timeout errors locking the authority file
/recalbox/share/system/.Xauthority

Hence the xserver fails to start.

Can a FAT32 drive be used as the external shared drive ?

Dragu

@retrotrimmer
Sure, also or even better ntsf. But this should be made best inside the Emulationstation, under System.