WizardStan
Mega GP Mania
- Joined
- May 24, 2008
- Messages
- 16,731
I have no idea how the bootmenu plays into the new boot loader and whether it is possible to create different boot menu options for SD installed 3.2 and 2.6 kernels. I could experiment with it a bunch until I understood better but I'm a little strapped for time right now. Best I can answer is "yes", modify boot.txt when you want to change kernels. You could even have two copies of boot.txt (boot.2nd or something?) and just rename back and forth as needed. Create a shell script to do it for you even: type "boot3.2" and it copies the 3.2 kernel boot.txt, or "boot2.6" and it copies the 2.6 kernel, for example.OK I have both kernels on the root of the fat partition on the SD. Am I to understand that I would have to modify boot.txt in a text editor between boots to change kernels on the SD? And that using the Menu to change kernels ONLY works with kernels on the NAND?
Is this correct? I have looked at the /boot/bootmenu and am starting to get this picture. If Booting from the Menu Always uses the NAND bootstrap <?> and only Autoboot.txt uses the NAND.
(Bare with me a bit longer please)
In otherwords, what is the function of the boot versus autoboot.txt? And why autoboot had to have mmc_core.removable=0 but not my boot.txt
...And if a mod wants to move this segway to a separate thread that is fine and I apologize if this got OT.
As far as boot.txt vs autoboot.txt, the only difference between the two is that autoboot.txt runs automatically and boot.txt needs to be selected from the R-trigger menu. They should be the exact same options, including mmc_core.removable=0.
If you select nothing, (or normal boot) first it checks the SD card for an autoboot.txt and boots from that if found, but if not (typical) it boots from the NANDs autoboot.txt. If you select SD card, then it looks to the SD card for boot.txt and boots from that if found.
You could probably add the following to your bootmenu.txt to boot from SD card
Code:
Boot from SD card (3.2)|setenv bootargs debug root=/dev/mmcblk0p3 rw rootdelay=2 vram=6272K omapfb.vram=0:3000K psplash=false mmc_core.removable=0; fatload mmc 0:1 0x80300000 uImage3.2 && bootm 0x80300000
Boot from SD card (2.6)|setenv bootargs debug root=/dev/mmcblk0p3 rw rootdelay=2 vram=6272K omapfb.vram=0:3000K psplash=false mmc_core.removable=0; fatload mmc 0:1 0x80300000 uImage2.6 && bootm 0x80300000
replacing uImage3.2 and uImage2.6 with whatever you've named the two different kernels, respectively.
I haven't tested either of these options personally, I've just copied them and modified slightly, but they should work, maybe.