Introduce a new sunxi-spl-with-ecc.bin image with already the right header, ECC, randomizer and padding for the BROM to be able to read it.
It needs to be flashed using a raw access to the NAND so that the controller doesn't change a thing to it, since we already have all the right parameters.
Signed-off-by: Maxime Ripard maxime.ripard@free-electrons.com Acked-by: Boris Brezillon boris.brezillon@free-electrons.com --- Makefile | 3 ++- board/sunxi/README.nand | 54 ++++++++++++++++++++++++++++++++++++++++++- scripts/Makefile.spl | 15 ++++++++++++- 3 files changed, 72 insertions(+), 0 deletions(-) create mode 100644 board/sunxi/README.nand
diff --git a/Makefile b/Makefile index 37cbcb28f75e..12a248e297b5 100644 --- a/Makefile +++ b/Makefile @@ -1345,6 +1345,9 @@ spl/u-boot-spl: tools prepare \ spl/sunxi-spl.bin: spl/u-boot-spl @:
+spl/sunxi-spl-with-ecc.bin: spl/sunxi-spl.bin + @: + spl/u-boot-spl.sfp: spl/u-boot-spl @:
diff --git a/board/sunxi/README.nand b/board/sunxi/README.nand new file mode 100644 index 000000000000..a5d4ff0e90a3 --- /dev/null +++ b/board/sunxi/README.nand @@ -0,0 +1,54 @@ +Allwinner NAND flashing +======================= + +A lot of Allwinner devices, especially the older ones (pre-H3 era), +comes with a NAND. NANDs storages are a pretty weak choice when it +comes to the reliability, and it comes with a number of flaws like +read and write disturbs, data retention issues, bloks becoming +unusable, etc. + +In order to mitigate that, various strategies have been found to be +able to recover from those issues like ECC, hardware randomization, +and of course, redundancy for the critical parts. + +This is obviously something that we will take into account when +creating our images. However, the BROM will use a quite weird pattern +when accessing the NAND, and will access only at most 4kB per page, +which means that we also have to split that binary accross several +pages. + +In order to accomodate that, we create a tool that will generate an +SPL image that is ready to be programmed directly embedding the ECCs, +randomized, and with the necessary bits needed to reduce the number of +bitflips. The U-Boot build system, when configured for the NAND will +also generate the image sunxi-spl-with-ecc.bin that will have been +generated by that tool. + +In order to flash your U-Boot image onto a board, assuming that the +board is in FEL mode, you'll need the sunxi-tools that you can find at +this repository: https://github.com/linux-sunxi/sunxi-tools + +Then, you'll need to first load an SPL to initialise the RAM: +sunxi-fel spl spl/sunxi-spl.bin + +Load the binaries we'll flash into RAM: +sunxi-fel write 0x4a000000 u-boot-dtb.bin +sunxi-fel write 0x43000000 spl/sunxi-spl-with-ecc.bin + +And execute U-Boot +sunxi-fel exe 0x4a000000 + +On your board, you'll now have all the needed binaries into RAM, so +you only need to erase the NAND... + +nand erase.chip + +Then write the SPL and its backup: + +nand write.raw.noverify 0x43000000 0 40 +nand write.raw.noverify 0x43000000 0x400000 40 + +And finally write the U-Boot binary: +nand write 0x4a000000 0x800000 0xc0000 + +You can now reboot and enjoy your NAND. \ No newline at end of file diff --git a/scripts/Makefile.spl b/scripts/Makefile.spl index e0b0117dc9b6..6a381f26d21a 100644 --- a/scripts/Makefile.spl +++ b/scripts/Makefile.spl @@ -168,6 +168,10 @@ endif
ifdef CONFIG_ARCH_SUNXI ALL-y += $(obj)/sunxi-spl.bin + +ifdef CONFIG_NAND_SUNXI +ALL-y += $(obj)/sunxi-spl-with-ecc.bin +endif endif
ifeq ($(CONFIG_SYS_SOC),"at91") @@ -276,6 +280,17 @@ cmd_mksunxiboot = $(objtree)/tools/mksunxiboot $< $@ $(obj)/sunxi-spl.bin: $(obj)/$(SPL_BIN).bin FORCE $(call if_changed,mksunxiboot)
+quiet_cmd_sunxi_spl_image_builder = SUNXI_SPL_IMAGE_BUILDER $@ +cmd_sunxi_spl_image_builder = $(objtree)/tools/sunxi-spl-image-builder \ + -c $(CONFIG_NAND_SUNXI_SPL_ECC_STRENGTH)/$(CONFIG_NAND_SUNXI_SPL_ECC_SIZE) \ + -p $(CONFIG_SYS_NAND_PAGE_SIZE) \ + -o $(CONFIG_SYS_NAND_OOBSIZE) \ + -u $(CONFIG_NAND_SUNXI_SPL_USABLE_PAGE_SIZE) \ + -e $(CONFIG_SYS_NAND_BLOCK_SIZE) \ + -s -b $< $@ +$(obj)/sunxi-spl-with-ecc.bin: $(obj)/sunxi-spl.bin + $(call if_changed,sunxi_spl_image_builder) + # Rule to link u-boot-spl # May be overridden by arch/$(ARCH)/config.mk quiet_cmd_u-boot-spl ?= LD $@