2018-11-05

Rockchip Boot flow


Here is Rockchip pre-released binaries which may be mentioned later:
https://github.com/rockchip-linux/rkbin
And Rockcip Linux GPT partition here.

Boot flow

Here is a table show the detail what we may use in Rockchip platform, for 2 boot stage:
- use U-Boot SPL;
- use Rockchp idbLoader which is combinded by Rockchip ddr init bin and miniloader bin;



Then when we talking about boot from eMMC/SD/U-Disk/net, they are in different concept:
  • Stage 1 is always in boot rom, it loads stage 2 and may load stage 3(when SPL_BACK_TO_BROM option enabled).
  • Boot from SPI flash means firmware for stage 2 and 3(SPL and U-Boot only) in SPI flash and stage 4/5 in other place;
  • Boot from eMMC means all the firmware(including stage 2, 3, 4, 5) in eMMC;
  • Boot from SD card means all the firmware(including stage 2, 3, 4, 5) in SD card;
  • Boot from U-Disk means firmware for stage 4 and 5(not including SPL and U-Boot) in Disk, optionally only including stage 5;
  • Boot from net/tftp means firmeware for stage 4 and 5(not including SPL and U-Boot) on the network;




Boot Flow 1 is typical Rockchip boot flow with Rockchip miniloader;
Boot Flow 2 is used for most SoCs with U-Boot TPL for ddr init and SPL for trust(ATF/OP-TEE) load and run into next stage;
Boot Flow 3 is use only for RK3399 with SPL ATF support;
Boot Flow 4 is used for armv7 SoCs which do not support trust;

Note 1. If loader1 have more than 1 stage, program will back to bootrom and bootrom load and run into next stage. eg. If loader1 is tpl and spl, the bootrom will run into tpl first, tpl init ddr and back to bootrom, bootrom then load and run into spl.
Note 2. If trust is enabled, loader1 need to load both trust and u-boot, and then run into trust in secure mode(EL3 in armv8), trust do the initialize and run into U-Boot in non-secure mode(EL2 in armv8).
Note 3. For trust(in trust.img or u-boot.itb), armv7 has only one tee.bin with or without ta, armv8 has bl31.elf and option with bl32.
Note 4. In boot.img, content can be zImage and its dtb for Linux, and can optionally be grub.efi, and can be AOSP boot.img, ramdisk is option;