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products:sbc:edge2:hardware:boot-sequence

Edge2 boot sequence

Edge2 have advanced and flexible boot possibilities

Common boot process

SPL loader

  • SPL-loader is a 1st boot-loader which can start from SPI-FlasheMMCSD card. By default its start from SPI-flash.
  • SPL-loader scan special areas for next U-Boot-loader by SDeMMCSPI-FLash

common logs

spl-boot-example.log
U-Boot SPL board init
U-Boot SPL 2017.09 (Aug 26 2022 - 15:50:37)
MCU: bootmode: 1, oowow 0
board_boot_order: /chosen found, using spl_boot_device()
!!! same-as-spl: 
!!! /mmc@fe2c0000: 
!!! /mmc@fe2e0000: 
!!! /spi@fe2b0000/flash@1: 
Trying to boot from MMC2 :: 0
Card did not respond to voltage select!
Trying to boot from MMC1 :: 1
Trying fit image at 0x4000 sector
Not fit magic
Trying fit image at 0x5000 sector
Not fit magic
Trying to boot from MTD2 :: 2
Trying fit image at 0x300 sector
...

oowow-mode logs

log spl-boot-oowow-mode-example.log
U-Boot SPL board init
U-Boot SPL 2017.09 (Aug 26 2022 - 15:50:37)
MCU: bootmode: 1, oowow 1
MCU: oowow 2
board_boot_order: /chosen found, using spl_boot_device()
!!! same-as-spl: 
+++ /spi@fe2b0000/flash@1: 
!!! /mmc@fe2c0000: 
!!! /mmc@fe2e0000: 
!!! /spi@fe2b0000/flash@1: 
Trying to boot from MTD2 :: 0
Trying fit image at 0x300 sector
...
Jumping to U-Boot(0x00200000) via ARM Trusted Firmware(0x00040000)
...

U-Boot loader

WIP:

U-Boot OS boot sequence

We discribe only about SPI-flash u-boot, for other custom U-boots which can stored at eMMC or SD its will be different

OS booting follow by distro_bootcmd which use boot_targets priority for scanning bootable OS. Step by step scan all available storage's and partitions for os-boot-configuration-extlinux-config

kedge2# printenv boot_targets 
boot_targets=usb0 mmc1 mmc0 pxe dhcp fail

WIP:

OS boot configuration - extlinux config

Basic example:

extlinux/extlinux.conf
menu background /logo.bmp
LABEL Default
  LINUX /Image
  INITRD /initrd.img
  FDTDIR /dtb
  APPEND ${bootargs} earlycon=uart8250,mmio32,0xfeb50000 console=ttyFIQ0 console=tty0 irqchip.gicv3_pseudo_nmi=0 root=LABEL=ROOTFS rootflags=data=writeback rw rootfstype=ext4
timeout  10
default Default

OOWOW mode

OOWOW mode can be activated by

WIP:

OOWOW special mode

WIP:

OOWOW rescue mode

WIP:

MCU register for start oowow

WIP:

Last modified: 2022/08/29 03:06 by hyphop