diff options
authorJason Hobbs <jason.hobbs@calxeda.com>2011-08-31 10:37:28 -0500
committerJohn Rigby <john.rigby@linaro.org>2011-09-23 07:10:38 -0600
commitfa57979ea8ed445820a24e1282c74bf60a5e6093 (patch)
parente13334c17174847790b1ec68f0e87105b2636c56 (diff)
README: document standard image variables
With these documented, we can start pushing towards standardizing their use across boards. Signed-off-by: Jason Hobbs <jason.hobbs@calxeda.com> Cc: Mike Frysinger <vapier@gentoo.org>
1 files changed, 19 insertions, 0 deletions
diff --git a/README b/README
index a43da97a4..6cae0f6d2 100644
--- a/README
+++ b/README
@@ -3507,6 +3507,25 @@ List of environment variables (most likely not complete):
Ethernet is encapsulated/received over 802.1q
VLAN tagged frames.
+The following image location variables contain the location of images
+used in booting. The "Image" column gives the role of the image and is
+not an environment variable name. The other columns are environment
+variable names. "File Name" gives the name of the file on a TFTP
+server, "RAM Address" gives the location in RAM the image will be
+loaded to, and "Flash Location" gives the image's address in NOR
+flash or offset in NAND flash.
+*Note* - these variables don't have to be defined for all boards, some
+boards currenlty use other variables for these purposes, and some
+boards use these variables for other purposes.
+Image File Name RAM Address Flash Location
+----- --------- ----------- --------------
+u-boot u-boot u-boot_addr_r u-boot_addr
+Linux kernel bootfile kernel_addr_r kernel_addr
+device tree blob fdtfile fdt_addr_r fdt_addr
+ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
The following environment variables may be used and automatically
updated by the network boot commands ("bootp" and "rarpboot"),
depending the information provided by your boot server: