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authorSourav Poddar2013-06-07 11:32:48 -0500
committerTom Rini2013-06-07 12:14:09 -0500
commit6aa127b4f525ab81455e99fc6e60faa57bd690a1 (patch)
tree2638c5f6a4d9527752dbc9b466ab1a7feeaeb3bf
parentab011ac8b3a560988dbc0761f714daeaafd766e7 (diff)
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README: qspi usecase and testing documentation.
Contains documentation and testing details for qspi flash interface. Signed-off-by: Sourav Poddar <sourav.poddar@ti.com>
-rw-r--r--README.dra_qspi_flash36
-rw-r--r--README.dra_qspi_test40
2 files changed, 76 insertions, 0 deletions
diff --git a/README.dra_qspi_flash b/README.dra_qspi_flash
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1QSPI U-boot support
2------------------
3
4Host processor is connected to serial flash device via qpsi
5interface. QSPI is a kind of spi module that allows single,
6dual and quad read access to external spi devices. The module
7has a memory mapped interface which provide direct interface
8for accessing data form external spi devices.
9
10The one QSPI in the device is primarily intended for fast booting
11from Quad SPI flash devices.
12
13Usecase1
14-------
15
16MLO/u-boot.img will be flashed from SD/MMC to the flash device
17using serial flash erase and write commands. Then, switch settings
18will be changed to qspi boot. Then, the ROM code will read MLO
19from the predefined location in the flash, where it was flashed and
20execute it after storing it in SDRAM. Then, the MLO will read
21u-boot.img from flash and execute it from SDRAM.
22
23
24Driver
25------
26drivers/qspi/ti_qspi.c
27 - Newly created file which is responsible for configuring the
28 qspi controller and also for providing the low level api which
29 is responsible for transferring the datas from host controller
30 to flash device and vice versa.
31
32Testing
33-------
34A seperated file named README.dra_qspi_test has been created which gives all the
35details about the commands required to test qspi at u-boot level.
36
diff --git a/README.dra_qspi_test b/README.dra_qspi_test
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1-------------------------------------------------
2 Simple steps used to test the QSPI at U-Boot
3-------------------------------------------------
4
5For #1, build the patched U-Boot and load MLO/u-boot.img
6
7----------------------------------
8Boot from another medium like MMC
9----------------------------------
10
11DRA752 EVM # mmc dev 0
12DRA752 EVM # fatload mmc 0 0x82000000 MLO
13DRA752 EVM # fatload mmc 0 0x82000000 u-boot.img
14
15--------------------------------------------------
16Commands to erase/write u-boot/mlo to flash device
17--------------------------------------------------
18
19DRA752 EVM # sf probe 0
20[should detect the S25FL256S serial flash device]
21
22DRA752 EVM # sf erase 0 10000
23DRA752 EVM # sf erase 10000 10000
24DRA752 EVM # sf erase 20000 10000
25DRA752 EVM # sf erase 30000 10000
26DRA752 EVM # sf erase 40000 10000
27DRA752 EVM # sf erase 50000 10000
28DRA752 EVM # sf erase 60000 10000
29
30DRA752 EVM # sf write 82000000 0 10000
31DRA752 EVM # sf write 83000000 80000 80000
32
33
34For #2, set sysboot to QSPI-1 boot mode and power on. ROM should find
35the GP header at offset 0 and load/execute SPL. SPL then detects that
36ROM was in QSPI-1 mode (boot code 10) and attempts to find a U-Boot
37image header at offset 0x80000 (set in the config file) and proceeds to
38load that image using the U-Boot image payload offset/size from the
39header. It will then start U-Boot.
40~