On 11. 06. 19 22:08, Jean-Francois Dagenais wrote: > Anyone? > >> On Jun 10, 2019, at 23:51, Jean-Francois Dagenais <[email protected]> >> wrote: >> >> Hi guys, >> >> Is this possible? I am shooting for fastest boot possible and thought this >> would be the way to achieve it. What is the smallest cost I have to expect >> for having u-boot proper in the boot flow? I.e. is my assumption that I must >> skip it to achieve fastest boot true. >> >> FYI, I've decided to postpone fpga load to linux init. This simplifies >> things a bit in SPL, but there is still the mix of ATF and Falcon which I am >> not sure. I am fuzzy on the ATF terminology so thank you for bearing with me >> as I learn. >> >> Can anyone point to a working example (board config .h and defconfig files >> for example) or which pieces are required to make it work. >> >> I found this on arm-community: "Solved the problem. U-Boot SPL copies ATF in >> OCRAM, and ATF calls Kernel directly passing in the FDT address." >> >> BTW, we boot both SD and eMMC on the same board. Right now I got my SPL to >> open a FIT image made by kernel-fitimage.bbclass but it obviously doesn't go >> far. >> >> But its still a bit vague. If I have to guess, the FIT image would describe >> to load the kernel at an address which also appears in my dts/dtb so ATF >> knows where to jump to next. >> >> Thanks for clues an pointers fellas! > > > Please help. Michal, I saw you were involved with this... > https://lists.denx.de/pipermail/u-boot/2016-October/269080.html > > I am drowning in a sea of legacy and generic code flows within SPL. I am > wondering what design/methods to use if doing a new zynqmp based design. I > see a bunch of flows where different images can be loaded: > > CONFIG_SPL_FS_LOAD_PAYLOAD_NAME > CONFIG_SPL_FS_LOAD_ARGS_NAME > CONFIG_SPL_FS_LOAD_KERNEL_NAME > > I see comments in include/configs/xilinx_zynqmp.h like "/* u-boot is like dtb > */" which adds to the confusion. > > ... or should I try, if at all possible, to boot directly to linux from FSBL? > Or do this > https://xilinx-wiki.atlassian.net/wiki/spaces/A/pages/18841976/Prepare+boot+image#Preparebootimage-Example:FSBLpre-loadsLinuximages > and make a very stripped down u-boot proper (no MMC driver needed), and boot > into pre-loaded kernel?
There is no real need to run any u-boot if you want to short boot up time. Just let fsbl to load ATF and ATF directly starts kernel. Thanks, Michal -- _______________________________________________ meta-xilinx mailing list [email protected] https://lists.yoctoproject.org/listinfo/meta-xilinx
