Hi Pawel, On 7 June 2017 at 09:37, Paweł Jarosz <paweljarosz3...@gmail.com> wrote: > Hi Simon, > > > W dniu 06.06.2017 o 23:10, Simon Glass pisze: >> >> Hi Pawel, >> >> On 6 June 2017 at 12:53, Paweł Jarosz <paweljarosz3...@gmail.com> wrote: >>> >>> Rockchip bootrom first reads 1KB data from nand at offset 0x10080C00 and >>> executes it. Then waits for back to bootrom and loads another 32KB to >>> sram >>> which also executes. Sdram initialisation code needs to be in one of >>> these two >>> steps. Then bootloader loads another ~200KB of data at offset 0x60000000 >>> and jumps to it. >>> >>> 32KB of data is a little low for tpl + spl part and ~200KB data is to low >>> for >>> u-boot part(for example to boot from mmc you need to disable usb support. >>> >>> My solution to size problem is to move sdram initialisation code to tpl >>> stage, >>> move spl part to third stage(reading 200KB data) and add support for >>> loading >>> u-boot by spl from ext2/4, fat partitions. >>> >>> But moving sdram initialisation code to tpl increases size of tpl above >>> 1KB >>> (first boot stage). Solution to this is to add code which will be below >>> 1KB >>> offset in tpl binary and do back to bootrom at very beginning of the tpl >>> execution. >> >> So do you mean that TPL starts and then loads more of itself? Why not >> put SDRAM init in SPL? You say above that 32KB is 'too low', but It's >> not clear why. > > Ad.1 No. Tpl starts and at the first execution returns to bootrom. Bootrom > then loads > rest of the tpl (31KB) and executes it for a second time.
So can we do this trick with SPL and drop TPL? > > Ad.2,3 Due to size issues (200KB limit) i needed to move main u-boot to mmc. > To load u-boot from > mmc by SPL (there is 32KB bootrom limit, not enough space for mmc support) i > moved SPL to sdram. > Code executed in sdram can't mess with sdram settings because it will hang > the board. Sdram setup > needs to be done by code in SRAM (tpl). You should be able to fit MMC and SDRAM into 32KB. E.g. I can build firefly-rk3288 that way as Heiko mentions > >>> Adding this few lines of code here meets these conditions. >>> >>> Signed-off-by: Paweł Jarosz <paweljarosz3...@gmail.com> >>> --- >>> arch/arm/cpu/armv7/start.S | 13 +++++++++++++ >>> 1 file changed, 13 insertions(+) >>> >>> diff --git a/arch/arm/cpu/armv7/start.S b/arch/arm/cpu/armv7/start.S >>> index f06fd28..73e03d9 100644 >>> --- a/arch/arm/cpu/armv7/start.S >>> +++ b/arch/arm/cpu/armv7/start.S >>> @@ -36,6 +36,19 @@ >>> #endif >>> >>> reset: >>> + >>> +#if defined(CONFIG_ROCKCHIP_RK3066) && defined(CONFIG_TPL_BUILD) >>> + ldr r3, =0x10080900 >>> + ldr r0, [r3] >>> + cmp r0, #1 >>> + movne r0, #1 >>> + strne r0, [r3] >>> + beq out_of_bootrom >>> + bx lr >>> +out_of_bootrom: >>> + mov r0, #0 >>> + str r0, [r3] >>> +#endif >>> /* Allow the board to save important registers */ >>> b save_boot_params >>> save_boot_params_ret: >>> -- >>> 2.7.4 Regards, Simon _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot
