Multi Boot

[maxycatz]

Running myself in circles with this....

How do I set up multiboot or access a boot menu on the C4 to switch between SD and eMMC (eg Android and Ubuntu)?

[tobetter]

Running myself in circles with this....

How do I set up multiboot or access a boot menu on the C4 to switch between SD and eMMC (eg Android and Ubuntu)?

Not like N2, ODROID-C4 does not have SPI flash memory and the Petitboot is not supporting by default. So we cannot switch between SD and eMMC as of now.

[maxycatz]

Yep, kinda got to that impression.

Seem to being thwarted quite a bit with the C4 at the mo'; the risk of being an early adopter I guess.

[odroid]

We have no plan to add a SPI flash memory to the C4 board due to the limited board space.

[joy]

This can be an alternate way to run petitboot without SPI Flash for multiboot and I used to use this layout before for development of petitboot spibios without spi flash.

petitboot.jpg (112.62 KiB) Viewed 519 times

Actually, it's a same way as the petitboot flow with SPI Flash,
(1) Booting from SPI flash (2) Run Petitboot (3) Scan available storage candidates (4) Select a storage as 2nd boot media,
except (1) Booting from another storage (like SD card or eMMC).

Example)
- Storage-A : SD card - has Boot loaders to boot C4 / Kernel, dtb, ramdisk for Petitboot / Another Kernel, dtb, uInitrd and rootfs for Image OS-A
- Storage-B : eMMC card - NO BLs to boot C4 / Kernel, dtb, uInitrd and rootfs for Image OS-B
- Storage-C : USB stick - N/A as a boot media / Kernel, dtb, uInitrd and rootfs for Image OS-C

Step1] Booting from Storage-A, SD Card
Step2] U-Boot - Load and Jump to kernel, dtb from vfat of SD Card
Step3] Kernel - Kernel Booting from kernel of SD card (The kernel is configured to run petitboot functions.)
Step4] Init - Start init service from ramdisk in SD Card (The ramdisk from SD Card includes essential packages, libs and services for petitboot.)
Step5] Petitboot - (1) Now start basic services (2) Scan available storage candidates using pb-discover (3) Start petitboot-nc (4) Display candidates
Step6] Petitboot - (5) Select 2nd boot media (6) Configure 2nd Kernel/dtb/uInitrd path and set kernel command based on 'kexec' (7) Jump to 2nd kernel and proceed a new kernel booting
Step7] Kernel of 2nd boot media
Step8] Configure rootfs from 2nd boot media based on new kernel command

From [Step1] to [Step6], resources are loaded from SD Card instead of SPI Flash.
And it's needed to modify u-boot.

[kyoumaH]

How would one go about loading petitboot and multibooting that way?

[maxycatz]

kyoumaH,

Is that kinda like a GRUB bootloader setup?

Very mucch a newbie at SBCs