On 29/11/18 4:48 PM, Simon Goldschmidt wrote: > On Thu, Nov 29, 2018 at 11:56 AM Miquel Raynal > <miquel.ray...@bootlin.com> wrote: >> >> Hi Vignesh, >> >>>>> While I think porting this from Linux is the right thing to do, I can't >>>>> say I'm happy with losing yet another 2.5 kB for SPL when it is already >>>>> too stuffed to add secure boot via FIT signatures. >>>> >>>> Indeed. Can we somehow trim things down a bit for SPL ? >>>> >>> >>> I am able to trim overall size delta to within 1KB for porter_defconfig. >>> Pushed new set of patches to github[1] >>> >>> With new this new SF framework and porter_defconfig: >>> size spl/u-boot-spl >>> text data bss dec hex filename >>> 15749 184 1100 17033 4289 spl/u-boot-spl >>> >>> Current mainline: >>> size spl/u-boot-spl >>> text data bss dec hex filename >>> 14881 184 1100 16165 3f25 spl/u-boot-spl >>> >>> Typical increase in code delta is ~1K to ~1.2KB wrt SPL on different >>> platforms depending on flash devices supports enabled. >>> >>> I am not sure if its possible to trim this down further, as there is >>> addition of new code to handle 4 Byte addressing feature and moving to >>> spi-mem framework to support direct mapping capable SPI controllers. >>> These features will add to code size and I hope that's an acceptable >>> tradeoff. >>> >>> I believe, once SPI NOR is completely integrated with MTD framework, >>> there will be some size reduction(such as due to getting rid of sf_mtd.c >>> and spi_flash_* APIs completely. Also, loading of U-Boot images across >>> NAND/SPI NOR can be consolidated). >> >> There are already multiple SPL-specific drivers out there. While I don't >> see a problem building MTD in U-Boot, I wonder if building MTD in the >> SPL is a good idea. Instead, Why not just build a tiny "SPL MTD stack", >> a lightweight MTD stack just with minimal features? > > I think that would be a good idea. Simple read access should probably > be enough for SPL to load U-Boot. That would free some space I need to > verify FIT signatures... >
Okay, I plan to implement spi-nor-tiny.c as part of next version that would support just discovering connected flash via JEDEC ID and reading images from flash at best possible IO mode with 4-byte addressing. This can serve as lightweight SPL stack for SPI NOR to overcome size limitations. Let me know if there are any concerns. Thanks for the suggestions! -- Regards Vignesh _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot