From: Mehmet Fide <[email protected]> The page tells how U-Boot gets into NAND but not how the BootROM finds it there. Name the Firmware Configuration Block, when it needs writing and the nandbcb command that writes it now, together with the Toradex configuration block that shares its NAND block and has to be read back after the rewrite.
Signed-off-by: Mehmet Fide <[email protected]> --- doc/board/toradex/colibri_vf.rst | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/doc/board/toradex/colibri_vf.rst b/doc/board/toradex/colibri_vf.rst index a010f9f5a2d..69f91af7ebd 100644 --- a/doc/board/toradex/colibri_vf.rst +++ b/doc/board/toradex/colibri_vf.rst @@ -14,6 +14,7 @@ Quick Start - Build U-Boot - Flash to NAND from a running U-Boot - Flash to NAND over recovery mode +- The NAND boot control block - Modules still carrying the WinCE bootloader Build U-Boot @@ -64,6 +65,30 @@ serial downloader on the USB client port. The `imx_usb_loader From the running U-Boot, flash NAND as in the previous section. +The NAND boot control block +--------------------------- + +The BootROM finds U-Boot through the Firmware Configuration Block in +the first NAND page: the ECC level and the page of the image. Modules +come with it, it needs writing again only after the first block was +erased or when the ECC layout of the NAND changes. With +``CONFIG_CMD_NANDBCB`` enabled, ``nandbcb`` writes the block the ROM +expects on the Vybrid, and ``nandbcb dump`` shows the one in NAND. The +same block holds the Toradex configuration block in its second page, +so read that page back after the rewrite: + +.. code-block:: none + + Colibri VFxx # nand read ${loadaddr} 0x800 0x800 + Colibri VFxx # nandbcb bcbonly 0 0x20000 0x160000 0x20000 0x160000 + Colibri VFxx # nand write ${loadaddr} 0x800 0x800 + Colibri VFxx # nandbcb dump 0 + +The offsets name the ``u-boot`` partition of the default ``mtdparts``, +which starts at 0x20000, for both firmware copies the ROM knows, as the +modules come with one image; ``nandbcb`` takes the whole device as its +first argument because the block sits at page 0 of the device. + Modules still carrying the WinCE bootloader ------------------------------------------- -- 2.55.0
