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Diffstat (limited to 'board')
| -rw-r--r-- | board/sunxi/MAINTAINERS | 6 | ||||
| -rw-r--r-- | board/sunxi/README.nand | 54 |
2 files changed, 60 insertions, 0 deletions
diff --git a/board/sunxi/MAINTAINERS b/board/sunxi/MAINTAINERS index 3f211293fe..91ca6eaf7a 100644 --- a/board/sunxi/MAINTAINERS +++ b/board/sunxi/MAINTAINERS @@ -269,6 +269,12 @@ M: VishnuPatekar <vishnupatekar0510@gmail.com> S: Maintained F: configs/Sinovoip_BPI_M3_defconfig +SUNCHIP CX-A99 BOARD +M: Rask Ingemann Lambertsen <rask@formelder.dk> +S: Maintained +F: configs/Sunchip_CX-A99_defconfig +W: https://linux-sunxi.org/Sunchip_CX-A99 + WEXLER-TAB7200 BOARD M: Aleksei Mamlin <mamlinav@gmail.com> S: Maintained diff --git a/board/sunxi/README.nand b/board/sunxi/README.nand new file mode 100644 index 0000000000..a5d4ff0e90 --- /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.
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