Signed-off-by: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx> --- .../boards/at91/microchip-ksz9477-evb.rst | 38 ++++++++++++++++++- 1 file changed, 36 insertions(+), 2 deletions(-) diff --git a/Documentation/boards/at91/microchip-ksz9477-evb.rst b/Documentation/boards/at91/microchip-ksz9477-evb.rst index 4c4c4aecbfb3..2a68c2a552cd 100644 --- a/Documentation/boards/at91/microchip-ksz9477-evb.rst +++ b/Documentation/boards/at91/microchip-ksz9477-evb.rst @@ -1,11 +1,45 @@ Microchip KSZ 9477 Evaluation board =================================== -This is an evaluation board for a switch that uses the at91sam9x5 CPU. +This is an evaluation board for the KSZ9477 switch that uses the sama5d36 CPU. The board uses Device Tree and supports multi image. -Building barebox: +Building barebox as second stage bootloader: .. code-block:: sh make ARCH=arm microchip_ksz9477_evb_defconfig + +There are also a separate defconfig for operating barebox as first stage +bootloader originating from SD Card. +This configuration doesn't yet support device-tree use as the NVM bootloader +(SoC ROM code) requires the first stage bootloader to fit into 64K. + +Generally, the first stage may comes from any of the following boot +sources (in that order): + +* SPI0 CS0 Flash +* SD Card +* NAND Flash +* SPI0 CS1 Flash +* I2C EEPROM + +After being loaded into SRAM by the NVM bootloader, the first stage does low +level clock initialization, configuration of the DDRAM controller and +bootstraps the second stage boot loader. + +SD Card Bootstrap +----------------- + +For boot from SD card, barebox additionally needs to be configured as +first stage bootloader: + +.. code-block:: sh + + make ARCH=arm microchip_ksz9477_evb_bootstrap_mmc_defconfig + +The resulting barebox image must be renamed to ``BOOT.BIN`` +and located in the root directory of the first FAT16/32 partition +on the SD Card/eMMC. After initialization, ``BOOT.BIN`` will look +for a ``barebox.bin`` in the same directory and load and execute it +from SDRAM. -- 2.20.1 _______________________________________________ barebox mailing list barebox@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/barebox
