[U-Boot] [PATCH] i.MX: Add documentation on how to use SPI NOR on MX28evk

[Mårten Wikman]

This adds necessary information on how to use U-boot on SPI NOR on MX28evk

Signed-off-by: Marten Wikman <marten.wikman at novia.fi>
---
 board/freescale/mx28evk/README | 26 ++++++++++++++++++++++----
 boards.cfg                     |  1 +
 doc/README.mxs                 | 25 +++++++++++++++++++++++++
 3 files changed, 48 insertions(+), 4 deletions(-)

diff --git a/board/freescale/mx28evk/README b/board/freescale/mx28evk/README
index 524f3fc..37e5d55 100644
--- a/board/freescale/mx28evk/README
+++ b/board/freescale/mx28evk/README
@@ -23,11 +23,19 @@ To boot MX28EVK from an SD card, set the boot mode
DIP switches as:
    * VDD 5V: To the left (off)
    * Hold Button: Down (off)

+
+To boot MX28EVK from SPI NOR flash, set the boot mode DIP switches as:
+   * Boot Mode Select: 0 0 1 0 (Boot from SSP2)
+   * JTAG PSWITCH RESET: To the right (reset disabled)
+   * Battery Source: Down
+   * Wall 5V: Up
+   * VDD 5V: To the left (off)
+   * Hold Button: Down (off)

 Environment Storage
 -------------------

-There are two targets for mx28evk:
+There are three targets for mx28evk:

 "make mx28evk_config"		- store enviroment variables into MMC

@@ -35,12 +43,22 @@ or

 "make mx28evk_nand_config"	- store enviroment variables into NAND flash

+or
+"make mx28evk_spi_config"	- store enviroment variables into SPI NOR flash
+
 Choose the target accordingly.

 Note: The mx28evk board does not come with a NAND flash populated from the
 factory. It comes with an empty slot (U23), which allows the insertion of a
-48-pin TSOP flash device.
-
-Follow the instructions from doc/README.mxs to generate a bootable SD card.
+48-pin TSOP flash device. SPI NOR flash is neither populated from the factory.
+It is possible to solder a SOIC memory on U49 or use a DIP8 on J89.
+To get SPI communication to work R320, R321,R322 and C178 has to be populated.
+Look in the schematics for component values.

+Follow the instructions from doc/README.mxs to generate a bootable SD card.
 Insert the SD card in slot 0, power up the board and U-boot will boot.
+
+Follow the instructions from  doc/README.mxs to generate a bootable SPI NOR
+memory.
+Make sure boot mode switches are correct, press POWER and U-boot will boot.
+
diff --git a/boards.cfg b/boards.cfg
index 944ed4c..b9ee7bd 100644
--- a/boards.cfg
+++ b/boards.cfg
@@ -203,6 +203,7 @@ mx23evk                      arm         arm926ejs
  mx23evk             freesca
 m28evk                       arm         arm926ejs   m28evk
   denx           mxs		m28evk
 mx28evk                      arm         arm926ejs   mx28evk
   freescale      mxs		mx28evk:ENV_IS_IN_MMC
 mx28evk_nand                 arm         arm926ejs   mx28evk
   freescale      mxs		mx28evk:ENV_IS_IN_NAND
+mx28evk_spi                  arm         arm926ejs   mx28evk
   freescale      mxs		mx28evk:ENV_IS_IN_SPI_FLASH
 sc_sps_1                     arm         arm926ejs   sc_sps_1
   schulercontrol mxs
 nhk8815                      arm         arm926ejs   nhk8815
   st             nomadik
 nhk8815_onenand              arm         arm926ejs   nhk8815
   st             nomadik       nhk8815:BOOT_ONENAND
diff --git a/doc/README.mxs b/doc/README.mxs
index 5d9e72f..8f03711 100644
--- a/doc/README.mxs
+++ b/doc/README.mxs
@@ -23,6 +23,7 @@ Contents
 2) Compiling U-Boot for a MXS based board
 3) Installation of U-Boot for a MXS based board to SD card
 4) Installation of U-Boot into NAND flash on a MX28 based board
+5) Installation of U-boot into SPI NOR flash on a MX28 based board

 1) Prerequisites
 ----------------
@@ -234,3 +235,27 @@ There are two possibilities when preparing an
image writable to NAND flash.
 	   In case the user needs to boot a firmware image bigger than 1Mb, the
 	   user has to adjust the "update_nand_firmware_maxsz" variable for the
 	   update scripts to work properly.
+
+	
+	
+5) Installation of U-Boot to SPI NOR flash on a MX28 based board
+---------------------------------------------------------------
+
+To boot a MX28 based board from SPI NOR, set the boot mode DIP
switches according
+to MX28 manual section 12.2.1 (Table 12-2), SSP2
+
+The file u-boot.sb can be directly written to SPI NOR from U-boot prompt.
+
+Load u-boot to RAM, this can be done in several ways and one way is
to use tftp:
+	=> tftp u-boot.sb 0x42000000
+
+Activate correct SPI NOR flash with:
+	=> sf probe 2:0
+
+First the blocks where U-boot should be written to needs to be erased:
+	=> sf erase 0x0 0x80000
+	
+Write u-boot.sb to SPI NOR with:
+	=> sf write 0x42000000 0 0x80000
+	
+Last step is to power up board and U-boot should start.
-- 
1.8.3.2