ARM: uniphier: enable distro boot

Switch to the distro boot for UniPhier platform.

 - Remove the environment vairalbes used to load images from raw
   block devices.

 - Keep the command to download images via tftp.  This will be
   useful to boot the kernel when no valid kernel image is ready
   yet in the file system.

 - Use root.cpio.gz instead of root.cpio.uboot because we always know
   the file size of the init ramdisk; it is loaded via either a file
   system or network.

 - Rename fit_addr_r to kernel_addr_r, which the distro command
   checks to get the load address of FIT image.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

1 files changed, 55 insertions, 0 deletions

diff --git a/doc/README.uniphier b/doc/README.uniphier
index 990806ab79..badfacd66a 100644
--- a/doc/README.uniphier
+++ b/doc/README.uniphier
@@ -332,6 +332,61 @@ for kernel, DTB, and Init ramdisk.
 If they are not displayed, the Verified Boot is not working.
 
 
+Deployment for Distro Boot
+--------------------------
+
+UniPhier SoC family boot the kernel in a generic manner as described in
+doc/README.distro .
+
+To boot the kernel, you need to deploy necesssary components to a file
+system on one of your block devices (eMMC, NAND, USB drive, etc.).
+
+The components depend on the kernel image format.
+
+[1] Bare images
+
+  - kernel
+  - init ramdisk
+  - device tree blob
+  - boot configuration file (extlinux.conf)
+
+Here is an exmple of the configuration file.
+
+-------------------->8--------------------
+menu title UniPhier Boot Options.
+
+timeout 50
+default UniPhier
+
+label UniPhier
+      kernel ../Image
+      initrd ../rootfs.cpio.gz
+      fdtdir ..
+-------------------->8--------------------
+
+Then, write 'Image', 'rootfs.cpio.gz', 'uniphier-ld20-ref.dtb' (DTB depends on
+your board), and 'extlinux/extlinux.conf' to the file system.
+
+[2] FIT
+
+  - FIT blob
+  - boot configuration file (extlinux.conf)
+
+-------------------->8--------------------
+menu title UniPhier Boot Options.
+
+timeout 50
+default UniPhier
+
+label UniPhier
+      kernel ../fitImage
+-------------------->8--------------------
+
+Since the init ramdisk and DTB are contained in the FIT blob,
+you do not need to describe them in the configuration file.
+Write 'fitImage' and 'extlinux/extlinux.conf' to the file system.
+
+
 UniPhier specific commands
 --------------------------