Container isolated U-Boot build enviromment for raspberry pi (and others)

build your customized u-boot raspberry pi bootloader

Features

• Targeted to 64bit Rapsberry PI 3/4
• Build environment isolated within container
• .config overrides via merge_config.sh
• Easy to customize
• Ready to go

Requirements

• Debian/Ubuntu hostsystem
• podman with non-root config
• uid/gid remapping enabled

Step 1 - Build container image

./build.sh

Step 2 - Configuration

Device/Archicture selection

Image configuration

To alter a set of build config variables, just place them within conf/config - the values are merged with the default board profile.

Step 3 - Build u-boot binary (64bit only)

The uboot-build script triggers the build process

build@32e99ec1ab77:~/uboot$ uboot-build 
  HOSTCC  scripts/basic/fixdep
  HOSTCC  scripts/kconfig/conf.o
  YACC    scripts/kconfig/zconf.tab.c
  LEX     scripts/kconfig/zconf.lex.c
  HOSTCC  scripts/kconfig/zconf.tab.o
  HOSTLD  scripts/kconfig/conf
#
# configuration written to .config
#
scripts/kconfig/conf  --syncconfig Kconfig
  UPD     include/config.h
  CFG     u-boot.cfg
  GEN     include/autoconf.mk.dep
...
  DTC     arch/arm/dts/bcm2711-rpi-4-b.dtb
  COPY    u-boot.bin
  SHIPPED dts/dt.dtb

Finally, u-boot.bin is copied into the bind mount to u-boot.bin

Step 4 - Raspberry PI Boot

Following file from the raspberry firmware package are required:

• bootcode.bin (raspberry v1 v2 v3)
• start*.elf (all)
• fixup*.dat (all)
• bcm*.dtb (all)

And additionally the u-boot.bin bootloader

Boot config

File config.txt

disable_splash=1

boot_delay=0
gpu_mem=16

enable_uart=1
kernel=u-boot.bin
arm_64bit=1

SD Card setup

• MBR (DOS) partition table
• FAT32 boot partition (first partition) with boot flag set
• Size min 50MB

References

• https://elinux.org/RPi_U-Boot
• https://www.raspberrypi.com/documentation/computers/raspberry-pi.html#boot-sequence

License

hypersolid is OpenSource and licensed under the Terms of GNU General Public Licence v2. You're welcome to contribute!