cmd: Add a SEAMA image load command

Add a command to load SEAMA (Seattle Image), a NAND flash
on-flash storage format.

This type of flash image is found in some D-Link routers such
as DIR-645, DIR-842, DIR-859, DIR-860L, DIR-885L, DIR890L and
DCH-M225, as well as in WD and NEC routers on the ath79
(MIPS), Broadcom BCM53xx, and RAMIPS platforms.

This U-Boot command will read and decode a SEAMA image from
raw NAND flash on any platform. As it is always using big endian
format for the data decoding is always necessary on platforms
such as ARM.

The command is needed to read a SEAMA-encoded boot image on the
D-Link DIR-890L router for boot from NAND flash in an upcoming
port of U-Boot to the Broadcom Northstar (BCM4709, BCM53xx)
architecture.

A basic test and documentation is added as well. The test must
be run on a target with NAND flash support and at least one
resident SEAMA image in flash.

Cc: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

2 files changed, 61 insertions, 0 deletions

diff --git a/doc/usage/cmd/seama.rst b/doc/usage/cmd/seama.rst
new file mode 100644
index 00000000000..356c00a7233
--- /dev/null
+++ b/doc/usage/cmd/seama.rst
@@ -0,0 +1,60 @@
+.. SPDX-License-Identifier: GPL-2.0+:
+
+seama command
+=============
+
+Synopsis
+--------
+
+::
+
+    seama <dst_addr> <index>
+
+Description
+-----------
+
+The seama command is used to load and decode SEAttle iMAges from NAND
+flash to memory.
+
+This type of flash image is found in some D-Link routers such as
+DIR-645, DIR-842, DIR-859, DIR-860L, DIR-885L, DIR890L and DCH-M225,
+as well as in WD and NEC routers on the ath79 (MIPS), Broadcom
+BCM53xx, and RAMIPS platforms.
+
+This U-Boot command will read and decode a SEAMA image from raw NAND
+flash on any platform. As it is always using big endian format for
+the data decoding is always necessary on platforms  such as ARM.
+
+dst_addr
+    destination address of the byte stream to be loaded
+
+index
+    the image index (0, 1, 2..) can be omitted
+
+Example
+-------
+
+::
+
+    => seama 0x01000000
+    Loading SEAMA image 0 from nand0
+    SEMA IMAGE:
+      metadata size 36
+      image size 8781764
+      checksum 054859cfb1487b59befda98824e09dd6
+    Decoding SEAMA image 0x01000040..0x01860004 to 0x01000000
+
+
+Configuration
+-------------
+
+The command is available if CONFIG_CMD_SEAMA=y.
+
+Return value
+------------
+
+The return value $? is set 0 (true) if the loading is succefull, and
+is set to 1 (false) in case of error.
+
+The environment variable $seama_image_size is set to the size of the
+loaded SEAMA image.
diff --git a/doc/usage/index.rst b/doc/usage/index.rst
index 38040468352..13e6939b38d 100644
--- a/doc/usage/index.rst
+++ b/doc/usage/index.rst
@@ -75,6 +75,7 @@ Shell commands
    cmd/sbi
    cmd/sf
    cmd/scp03
+   cmd/seama
    cmd/setexpr
    cmd/size
    cmd/sleep