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Diffstat (limited to 'qemu/roms/u-boot/doc/SPI/README.sandbox-spi')
| -rw-r--r-- | qemu/roms/u-boot/doc/SPI/README.sandbox-spi | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/qemu/roms/u-boot/doc/SPI/README.sandbox-spi b/qemu/roms/u-boot/doc/SPI/README.sandbox-spi new file mode 100644 index 000000000..bb73eaf28 --- /dev/null +++ b/qemu/roms/u-boot/doc/SPI/README.sandbox-spi @@ -0,0 +1,64 @@ +Sandbox SPI/SPI Flash Implementation +==================================== + +U-Boot supports SPI and SPI flash emuation in sandbox. This must be enabled +using the --spi_sf paramter when starting U-Boot. + +For example: + +$ make O=sandbox sandbox_config +$ make O=sandbox +$ ./sandbox/u-boot --spi_sf 0:0:W25Q128:b/chromeos_peach/out/image.bin + +The four parameters to spi_sf are: + + SPI bus number (typically 0) + SPI chip select number (typically 0) + SPI chip to emulate + File containing emulated data + +Supported chips are W25Q16 (2MB), W25Q32 (4MB) and W25Q128 (16MB). Once +U-Boot it started you can use 'sf' commands as normal. For example: + +$ ./b/sandbox/u-boot --spi_sf 0:0:W25Q128:b/chromeos_peach/out/image.bin \ + -c "sf probe; sf test 0 100000; sf read 0 1000 1000; \ + sf erase 1000 1000; sf write 0 1000 1000" + + +U-Boot 2013.10-00237-gd4e0fdb (Nov 07 2013 - 20:08:15) + +DRAM: 128 MiB +Using default environment + +In: serial +Out: serial +Err: serial +SF: Detected W25Q128BV with page size 256 Bytes, erase size 4 KiB, total 16 MiB +SPI flash test: +0 erase: 1 ticks, 1024000 KiB/s 8192.000 Mbps +1 check: 2 ticks, 512000 KiB/s 4096.000 Mbps +2 write: 6 ticks, 170666 KiB/s 1365.328 Mbps +3 read: 0 ticks, 1048576000 KiB/s -201326.-592 Mbps +Test passed +0 erase: 1 ticks, 1024000 KiB/s 8192.000 Mbps +1 check: 2 ticks, 512000 KiB/s 4096.000 Mbps +2 write: 6 ticks, 170666 KiB/s 1365.328 Mbps +3 read: 0 ticks, 1048576000 KiB/s -201326.-592 Mbps +SF: 4096 bytes @ 0x1000 Read: OK +SF: 4096 bytes @ 0x1000 Erased: OK +SF: 4096 bytes @ 0x1000 Written: OK + + +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 +FFEF4018 + + +Simon Glass +sjg@chromium.org +7/11/2013 +Note that the sandbox SPI implementation was written by Mike Frysinger +<vapier@gentoo.org>. |