Hi Michal,
2016-10-05 23:39 GMT+09:00 Michal Simek <[email protected]>: > Hi Masahiro, > > 2016-10-04 20:19 GMT-07:00 Masahiro Yamada <[email protected]>: > >> Hi. >> >> Recently I implemented ARM Trusted Firmware BL31 for my SoCs. >> >> But, I am wondering how the boot-flow should be. >> >> >> >> Here is my situation. >> >> >> [1] >> When my company developed its first ARMv8 SoC, >> I had to bring up the system very quickly. >> >> I was familiar with U-Boot and Linux to some extent, but not with ATF >> at that time. >> Also I was too pressed, so I decided to build up the system without ATF. >> >> The boot-flow was like this: >> >> BootROM -> U-Boot SPL -> U-Boot proper -> Linux >> >> In this flow, the secure runtime firmware is missing, >> so I used Spin-Table for the enable-method. >> >> >> [2] >> Now I finished porting ATF BL31. >> The low-level init code (basic SoC init + DRAM initialization) >> already exists in U-Boot SPL. >> So, I am currently re-using SPL, like follows: >> >> BootROM -> U-Boot SPL -> ATF BL31 -> U-Boot proper (=BL33) -> Linux >> >> >> As far as I know, SPL can not load multiple images such as BL31, BL32, BL33 >> (here BL32 is optional). >> So, I hacked my SPL to load multi images >> and jump to BL31. >> > > this is not entirely truth. If you look at zynqmp you will find out that if > you > work with atf as kernel and full u-boot as dtb then u-boot SPL can load two > images. > This is what I use. It is a trick but I am not using any changes to get it > work. Ah, now I see. The idea I came up with was to put every ATF stuff into spl_board_prepare_for_boot(). > > We are using only BL31 and nothing else. But, prior to commit f3d1cc2ff387ffe22ccd1bdcb2a998ec46149c6d (ARM64: zynqmp: Enable SPL for all zynqmp boards), BootROM -> fsbl -> ATF BL31 -> U-Boot -> Linux was the only supported solution, yes? >> >> >> Recently I saw Simon's binman patches. >> It provides a fancy way to pack multiple firmware components into a >> single image, >> but I did not see the systematic way to load every entry in the image. >> (under way?) >> >> >> I was wondering if I should move my low-level init code >> from SPL to ATF BL2 or somewhere. >> >> Comments are welcome. >> > > I use bootrom -> SPL -> ATF -> full u-boot. > > I want to use SPL because we have all device drivers in u-boot and > in ATF we have only serial driver. If you want to use BL2 just for low > level init stuff > you can but it is the question if this brings you any value. Yes. This is one big advantage of using SPL over BL2. -- Best Regards Masahiro Yamada _______________________________________________ U-Boot mailing list [email protected] http://lists.denx.de/mailman/listinfo/u-boot
