Changes between Version 9 and Version 10 of ventana/bootloader

Timestamp:

11/29/2018 09:30:19 PM (7 years ago)

Author:

Cale Collins

Comment:

uboot env tools refresh, examples and clarification added.

ventana/bootloader

@@ -484 +484 @@
 }}}
 
+* ''Booting rootfs from microSD does not necessarily constitute "NAND-less", env variables are still stored on NAND when NAND is present.''
+
+
+
 It is important to realize the meaning of the '''Warning: Bad CRC, using default environment''' message. This means that the non-volatile env area is empty or corrupt (Note that this is the way Gateworks boards ship by default) and that the built-in env within U-Boot will be used.
 
 If you use {{{fw_setenv}}} on an environment in this state it will properly set the variable you specify and all other variables will continue to use their built-in default values within U-Boot. Essentially you are 'overriding' the defaults as you would expect.
+
+
+==== Configuring u-boot-tools 
+A file defining where your environment is located must be present for u-boot-tools to work.  Without this file you will receive an error:
+{{{#!bash
+Cannot parse config file '/etc/fw_env.config': No such file or directory
+}}}
+Examples:
+* Ventana booting from NAND
+{{{#!bash
+#Create config file
+cat << EOF > /etc/fw_env.config
+# device  offset size erasesize
+/dev/mtd1 0x0 0x20000 0x40000
+/dev/mtd1 0x80000 0x20000 0x40000
+EOF
+}}}
+* Ventana MMC only
+{{{#!bash
+#Create config file
+cat << EOF > /etc/fw_env.config
+# device  offset size erasesize
+/dev/mmcblk0 0xb1400 0x20000 0x20000
+/dev/mmcblk0 0xd1400 0x20000 0x20000
+EOF
+}}}
+* A file for building an image
+{{{#!bash
+#Create config file
+cat << EOF > /working/fw_env.config
+# device  offset size erasesize
+envVentana.bin 0x00000 0x20000
+envVentana.bin 0x20000 0x20000
+EOF
+}}}
+
+This will define the device being used, offset according to flash layout, size from flash map, and size of erase block (unless the device is a file).  Ventana U-boot environment is redundant hence two entries, both locations need their variables updated.  
+
+==== Usage example 
+
+{{{#!bash
+# display environment 
+fw_printenv 
+# set environment variable 
+fw_setenv foo bar #foo being variable name bar being value variable will be set to
+#second example 
+fw_setenv ipaddr 192.168.1.10
+#print single environment variable
+fw_printenv foo
+#second example
+fw_printenv ipaddr
+}}}