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- 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>.
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