I'm setting up gentoo on a banana pi M1+, and I can't get it to boot off a newly compiled kernel. I setup the SD card using this tutorial

http://wiki.gentoo.org/wiki/Banana_P...ile_the_Kernel

with the difference that I compiled natively and didn't cross compile. So far, so good, I can run gentoo linux on the BPI now. But, the kernel from the tutorial is quite old, and I wanted to update. I compiled the new uImage file with an updated source, and copied it over to /boot/uImage. It wouldn't boot up, and produced no messages.

I have tried a number of variations on this, and I'm really stumped. Apparently the BPI and a lot of arm SBCs use a bootloader called u-boot

http://linux-sunxi.org/U-Boot#Compile_U-Boot

When I follow these directions and create a new boot.scr, u-boot seems to ignore it. Interestingly, the setup from the tutorial follows the directions for NAND using uEnv.txt, even though this is an SD card.

It's unclear what the issue is. Does anyone have any thoughts?

u-boot definitely uses uEnv.txt. Do it that way. It doesn't care what disk you're on as long as it can get kernel, initrd, & root drive. Mine's a RazPi and I can use or dispense with uboot.

business_kid, thanks, I did some experimenting and that version of uboot is definitely reading uEnv.txt. One limitation was that the version of uboot I was using didn't show any messages or prompts, so it was hard to tell what was going on. So, I compiled a newer version of uboot from this github

https://github.com/andy-shev/u-boot

With the new uboot binary written to the boot sector, I get an actual uboot screen, critically including the error messages. I'm seeing this message

Loading Environment from FAT... *** Warning - bad CRC, using default environment

Interestingly, this new version of uboot seems to need uboot.env. At first I thought uboot.env served the same role as uEnv.txt, but copying uEnv.txt to uboot.env did not change this error. Eventually I found this documentation, which shows that uboot.env is a binary

http://bootlin.com/blog/mkenvimage-u...env-generator/

Following their pattern, I tried to make my own

mkenvimage -s 0x4200 -o uboot.env uboot-env.txt

Using a configuration file uboot-env.txt, which is basically the same as the uEnv.txt file

bootargs=console=ttyS0,115200 console=tty0 sunxi_ve_mem_reserve=0 sunxi_g2d_mem_reserve=0 sunxi_no_mali_mem_reserve console=tty1 root=/dev/mmcblk0p2 rootfstype=ext4 elevator=deadline rootwait
aload_script=fatload mmc 0 0x43000000 script.bin;
aload_kernel=fatload mmc 0 0x40008000 uImage; bootm 0x40008000;
bootcmd=run aload_script aload_kernel

The error persists, though. Any thoughts?

I have a disk backup of my RazPi and there's no uBoot.env file. Mind you, the RazPi does funny things of it's own. The gpu serial loads it's own firmware and the cpu's firmware. Then they both run around like headless chickens, setting switches, turning knobs and pulling levers so actually looking at the kernel is nearly an afterthought.

If it was a RazPi I could try to help. But all the arm SoCs have their own nutty way of doing stuff

get kernel, initrd, & root drive, Load from FAT that you've had bootm 0x40008000 backup. I try to help
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