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     Simple steps used to test the QSPI at U-Boot
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  For #1, build the patched U-Boot and load MLO/u-boot.img
  
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  Boot from another medium like MMC
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  U-Boot# mmc dev 0
  mmc0 is current device
  U-Boot# fatload mmc 0 0x82000000 MLO
  reading MLO
  55872 bytes read in 8 ms (6.7 MiB/s)
  U-Boot# fatload mmc 0 0x83000000 u-boot.img
  reading u-boot.img
  248600 bytes read in 19 ms (12.5 MiB/s)
  
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  Commands to erase/write u-boot/mlo to flash device
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  U-Boot# sf probe 0
  SF: Detected S25FL256S_64K with page size 256 Bytes, erase size 64 KiB, total 32 MiB, mapped at 5c000000
  SF: Warning - Only lower 16MiB accessible, Full access #define CONFIG_SPI_FLASH_BAR
  U-Boot# sf erase 0 0x10000
  SF: 65536 bytes @ 0x0 Erased: OK
  U-Boot# sf erase 0x20000 0x10000
  SF: 65536 bytes @ 0x20000 Erased: OK
  U-Boot# sf erase 0x30000 0x10000
  SF: 65536 bytes @ 0x30000 Erased: OK
  U-Boot# sf erase 0x40000 0x10000
  SF: 65536 bytes @ 0x40000 Erased: OK
  U-Boot# sf erase 0x50000 0x10000
  SF: 65536 bytes @ 0x50000 Erased: OK
  U-Boot# sf erase 0x60000 0x10000
  SF: 65536 bytes @ 0x60000 Erased: OK
  U-Boot# sf write 82000000 0 0x10000
  SF: 65536 bytes @ 0x0 Written: OK
  U-Boot# sf write 83000000 0x20000 0x60000
  SF: 393216 bytes @ 0x20000 Written: OK
  
  For #2, set sysboot to QSPI-1 boot mode(SYSBOOT[5:0] = 100110) and power
  on. ROM should find the GP header at offset 0 and load/execute SPL. SPL
  then detects that ROM was in QSPI-1 mode (boot code 10) and attempts to
  find a U-Boot image header at offset 0x20000 (set in the config file)
  and proceeds to load that image using the U-Boot image payload offset/size
  from the header. It will then start U-Boot.