ARM i.MX35: Add support for the Amazon Kindle3

The Amazon Model No. D00901 Kindle3 is an E-Book reader based on the
i.MX35 SOC. The device boots in internal boot mode from a build-in eMMC,
alternatively the device may be set into USB-downloader mode when the
Vol+ key is pressed on startup.

Add support for this device and make barebox a drop-in replacement for
the factory shipped u-boot image.
Constraints for the use as drop-in replacement:
- imximg header (offset 0x400) has a maximum size of 2kB minus 16 byte
  since the last 16 bytes are used to store a vendor specific hardware
  desctription identifier
- the bootloader space (application plus env) is limited to 256kB minus
  16 bytes when installed with offset of 4kB (the u-boot offset was 3kB).
  A vendor specific device identifier is stored in the gap between
  application and kernel. The vendor specific identifiers should not
  be overwritten.

Notable features:
- Support for eMMC, USB, UART, I2C, SPI and Keys (except keyboard)
- Full support for vendor specific ATAGs
- usbserial barebox console access by pressing Select button at startup,
  alternatively full console support on connector J14.

Signed-off-by: Alexander Kurz <akurz@blala.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 28 insertions, 0 deletions

diff --git a/Documentation/boards/imx/amazon-kindle3.rst b/Documentation/boards/imx/amazon-kindle3.rst
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+Amazon Kindle 3 "Kindle Keyboard" Model No. D00901
+==================================================
+
+This e-book reader is based on a Freescale i.MX35 SOC.
+The device is equiped with:
+
+* 256MiB synchronous dynamic RAM
+* 4GiB eMMC
+* a MC13892 PMIC
+
+The device boots in internal boot mode from eMMC and is shipped with a
+vendor modified u-boot imximage.
+
+To upload and run a new bootloader the device can be put into USB-downloader
+mode by the SOC microcode when Vol+ is pressed during startup. A new USB
+device "SE Blank RINGO" should appear, barebox may be uploaded using
+$ scripts/imx/imx-usb-loader barebox.imximg
+
+Note: a USB serial ACM console will be launched by a barebox init script
+when the cursor select key is pressed during startup (e.g. before running
+imx-usb-loader)
+
+Barebox may be used as drop-in replacement for the shipped bootloader.
+When installing the barebox imximg on the eMMC take care not to overwrite
+the partition table and vendor supplied serial numbers stored on the eMMC.
+e.g. just write the imx-header and the application section:
+memcpy -b -s barebox.imximg -d /dev/disk0.imx_header 1024 0 1024
+memcpy -b -s barebox.imximg -d /dev/disk0.self 4096 0 195584