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Diffstat (limited to 'roms/u-boot/doc/SPI/README.sandbox-spi')
| -rw-r--r-- | roms/u-boot/doc/SPI/README.sandbox-spi | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/roms/u-boot/doc/SPI/README.sandbox-spi b/roms/u-boot/doc/SPI/README.sandbox-spi new file mode 100644 index 000000000..f6a55fe78 --- /dev/null +++ b/roms/u-boot/doc/SPI/README.sandbox-spi @@ -0,0 +1,42 @@ +Sandbox SPI/SPI Flash Implementation +==================================== + +U-Boot supports SPI and SPI flash emulation in sandbox. This must be enabled +via a device tree. + +For example: + + spi@0 { + #address-cells = <1>; + #size-cells = <0>; + reg = <0 1>; + compatible = "sandbox,spi"; + cs-gpios = <0>, <&gpio_a 0>; + spi.bin@0 { + reg = <0>; + compatible = "spansion,m25p16", "jedec,spi-nor"; + spi-max-frequency = <40000000>; + sandbox,filename = "spi.bin"; + }; + }; + +Supported chips are W25Q16 (2MB), W25Q32 (4MB) and W25Q128 (16MB). Once +U-Boot it started you can use 'sf' commands as normal. For example: + +$ dd if=/dev/zero of=spi.bin bs=1M count=2 +$ u-boot -T + +Since the SPI bus is fully implemented as well as the SPI flash connected to +it, you can also use low-level SPI commands to access the flash. For example +this reads the device ID from the emulated chip: + +=> sspi 0 32 9f +SF: Detected m25p16 with page size 256 Bytes, erase size 64 KiB, total 2 MiB +FF202015 + + +Simon Glass +sjg@chromium.org +7/11/2013 +Note that the sandbox SPI implementation was written by Mike Frysinger +<vapier@gentoo.org>. |