[U-Boot] Add alternative boot method and options to LCD menu

[hansemro]

In a recent commit to my fork of U-Boot (hansemro/kf_u-boot@f331961), I added support for booting kernels and dtb in the boot directory of the system partition (as a proof of concept).

Currently, I am considering whether I should repartition to maximize the root directory and eliminate everything related to Android. If I do so and eliminate the standard Android boot partition, the normal boot method is rendered useless. This commit aims to fix that issue by adding a new menu option to boot the kernel (boot/zImage) and device tree blob (boot/omap4-kc1.dtb) on partition 9 (hard-coded for now).

[hansemro]

[hansemro]

The only advantage I see with Android boot image is the convenience that comes with fastboot. It certainly makes testing new kernels much more convenient.

[hansemro]

Should I make u-boot configurable (uEnv.txt) like with other ARM boards?

https://linux-sunxi.org/UEnv.txt
https://stackoverflow.com/questions/28891221/uenv-txt-vs-boot-scr

[hansemro]

Should I add usbboot to the main menu?

[hansemro]

[mj-sakellaropoulos]

These are all very good ideas.

Maybe in the future we can update u-boot a more recent version too.

[    6.928100] Power Management for TI OMAP4+ devices.
[    6.933227] OMAP4 PM: u-boot >= v2012.07 is required for full PM support

This message appears at boot even though u-boot version is 2014+

[mj-sakellaropoulos]

Ideas:

• Boot from USB menu entry (require gpt, with specific partition names)
• add kc1panel command for dss/dispc regdump

[hansemro]

It seems the new u-boot changes made the image too large for the bootloader partition.

[mj-sakellaropoulos]

Hmm, that's unfortunate, because as-is, there is not even boot from removable USB support. I guess the partition table has to be redone..

[hansemro]

I guess the partition table has to be redone..

I wouldn't mind doing this since I don't plan on returning to Android any time soon with this device. Even without doing so, you can run the debug bootloader with omap4boot.

[hansemro]

u-boot_debug.zip
I trimmed enough to build a flashable image (if that is important). However, you lose Hush shell, detailed help, and some debug commands. FIR coefficients will not be printed since they were all zeros.

Download the built image or build it yourself from the kc1_debug branch of my u-boot fork: https://github.com/hansemro/kf_u-boot/tree/kc1_debug

If you are just going to use omap4boot to dump register contents, then compile from p-ti-u-boot-2014.01 branch.

[hansemro]

Note: dump_gptimer requires a number between 1 and 11 (inclusive) as an argument to specify which timer to examine. Similarly, dump_gpio requires a number between 1 and 6 (inclusive).