Hi Lukasz >> >> >My point here is to first load SPL u-boot (which size is around 110 >> >KiB), and then download via DFU full-featured u-boot, which would be >> >placed in SDRAM. >> >> Yes this is good idea, so the SPL-DFU will have only RAM device >> support (to load u-boot into DDR). But we don't have DFU command to >> jump to u-boot after loading u-boot into DDR.
>I think that we don't need dfu command in SPL to boot fully-featured u-boot. >Lets consider following scenario: >- ROM bootloader (IPL) fetches SPL u-boot via USB. Then it passes > execution to it. >- The running SPL downloads fully-fledged u-boot [*] to RAM and passes > execution to it (as it is done in board_init_r @ ./common/spl/spl.c). > There is no need for any special command(s) to do that. >- Fully-blown u-boot flashes all needed images and reboots the board. >- Now the board is setup with proper u-boot, kernel and rootfs > [*] - This version of u-boot only requires to have hardcoded "bootcmd" >env variable. It would consist the list of commands needed for flashing your >target board. The "dfu_alt_info" should be hardcoded as well. >> The DFU basically just >> download firmware to memory devices like mmc/sd/eMMC/RAM. >> So the >> question is how to transfer control to u-boot after downloading the >> u-boot to DDR using SPL-DFU/RAM. > Please consult board_init_r function at ./common/spl/spl.c Yes, this is common u-boot flow, make sense, I was thinking exiting from DFU loop, user has to press Ctrl+C to exit from DFU after download of u-boot to IRAM. We can leverage the existing DFU/RAM support. Main concern is SPL+DFU size. I will rework and come back on how much size can be reduced. Thanks Lukasz for great support. Regards Ravi _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
