doc: board: Convert i.MX6 Sabresd README to reST

Convert plain text documentation to reStructuredText format and add
it to Sphinx TOC tree. No essential content change.

Signed-off-by: Peng Fan <peng.fan@nxp.com>

2 files changed, 133 insertions, 0 deletions

diff --git a/doc/board/freescale/index.rst b/doc/board/freescale/index.rst
index cc079ca..716bb1e 100644
--- a/doc/board/freescale/index.rst
+++ b/doc/board/freescale/index.rst
@@ -15,3 +15,4 @@ Freescale
    imxrt1020-evk
    imxrt1050-evk
    mx6sabreauto
+   mx6sabresd
diff --git a/doc/board/freescale/mx6sabresd.rst b/doc/board/freescale/mx6sabresd.rst
new file mode 100644
index 0000000..fe15ba7
--- /dev/null
+++ b/doc/board/freescale/mx6sabresd.rst
@@ -0,0 +1,132 @@
+.. SPDX-License-Identifier: GPL-2.0+
+
+mx6sabresd
+==========
+
+How to use and build U-Boot on mx6sabresd
+-----------------------------------------
+
+The following methods can be used for booting mx6sabresd boards:
+
+1. Booting from SD card
+
+2. Booting from eMMC
+
+3. Booting via Falcon mode (SPL launches the kernel directly)
+
+
+1. Booting from SD card via SPL
+-------------------------------
+
+mx6sabresd_defconfig target supports mx6q/mx6dl/mx6qp sabresd variants.
+
+In order to build it:
+
+.. code-block:: bash
+
+   $ make mx6sabresd_defconfig
+   $ make
+
+This will generate the SPL and u-boot-dtb.img binaries.
+
+- Flash the SPL binary into the SD card:
+
+.. code-block:: bash
+
+   $ sudo dd if=SPL of=/dev/sdX bs=1K seek=1 conv=notrunc && sync
+
+- Flash the u-boot-dtb.img binary into the SD card:
+
+.. code-block:: bash
+
+   $ sudo dd if=u-boot-dtb.img of=/dev/sdX bs=1K seek=69 conv=notrunc && sync
+
+2. Booting from eMMC
+--------------------
+
+.. code-block:: bash
+
+   $ make mx6sabresd_defconfig
+   $ make
+
+This will generate the SPL and u-boot-dtb.img binaries.
+
+- Boot first from SD card as shown in the previous section
+
+In U-boot change the eMMC partition config::
+
+   => mmc partconf 2 1 0 0
+
+Mount the eMMC in the host PC::
+
+   => ums 0 mmc 2
+
+- Flash SPL and u-boot-dtb.img binaries into the eMMC:
+
+.. code-block:: bash
+
+   $ sudo dd if=SPL of=/dev/sdX bs=1K seek=1 conv=notrunc && sync
+   $ sudo dd if=u-boot-dtb.img of=/dev/sdX bs=1K seek=69 conv=notrunc && sync
+
+Set SW6 to eMMC 8-bit boot: 11010110
+
+3. Booting via Falcon mode
+--------------------------
+
+.. code-block:: bash
+
+  $ make mx6sabresd_defconfig
+  $ make
+
+This will generate the SPL image called SPL and the u-boot-dtb.img.
+
+- Flash the SPL image into the SD card
+
+.. code-block:: bash
+
+   $ sudo dd if=SPL of=/dev/sdX bs=1K seek=1 oflag=sync status=none conv=notrunc && sync
+
+- Flash the u-boot-dtb.img image into the SD card
+
+.. code-block:: bash
+
+   $ sudo dd if=u-boot-dtb.img of=/dev/sdX bs=1K seek=69 oflag=sync status=none conv=notrunc && sync
+
+Create a partition for root file system and extract it there
+
+.. code-block:: bash
+
+   $ sudo tar xvf rootfs.tar.gz -C /media/root
+
+The SD card must have enough space for raw "args" and "kernel".
+To configure Falcon mode for the first time, on U-Boot do the following commands:
+
+- Setup the IP server::
+
+   # setenv serverip <server_ip_address>
+
+- Download dtb file::
+
+   # dhcp ${fdt_addr} imx6q-sabresd.dtb
+
+- Download kernel image::
+
+   # dhcp ${loadaddr} uImage
+
+- Write kernel at 2MB offset::
+
+   # mmc write ${loadaddr} 0x1000 0x4000
+
+- Setup kernel bootargs::
+
+   # setenv bootargs "console=ttymxc0,115200 root=/dev/mmcblk1p1 rootfstype=ext4 rootwait quiet rw"
+
+- Prepare args::
+
+   # spl export fdt ${loadaddr} - ${fdt_addr}
+
+- Write args 1MB data (0x800 sectors) to 1MB offset (0x800 sectors)::
+
+   # mmc write 18000000 0x800 0x800
+
+- Press KEY_VOL_UP key, power up the board and then SPL binary will launch the kernel directly.