Enabling the distro options
---------------------------
+In your board's defconfig, enable the DISTRO_DEFAULTS option by adding
+a line with "CONFIG_DISTRO_DEFAULTS=y". If you want to enable this
+from Kconfig itself, for e.g. all boards using a specific SoC then
+add a "default y if ARCH_FOO" to the DISTRO_DEFAULTS section of
+the Kconfig file in the root of the u-boot sources.
+
In your board configuration file, include the following:
------------------------------------------------------------
#ifndef CONFIG_SPL_BUILD
-#include <config_distro_defaults.h>
#include <config_distro_bootcmd.h>
#endif
------------------------------------------------------------
specific boot.scr scripts are enabled. This enables distros to generate a
U-Boot-specific boot.scr script rather than extlinux.conf as the boot
configuration file. While doing so is fully supported, and
-<config_distro_defaults.h> exposes enough parameterization to boot.scr to
+CONFIG_DISTRO_DEFAULTS exposes enough parameterization to boot.scr to
allow for board-agnostic boot.scr content, this document recommends that
distros generate extlinux.conf rather than boot.scr. extlinux.conf is intended
to work across multiple bootloaders, whereas boot.scr will only work with
A size of 16MB for the kernel is likely adequate.
-pxe_addr_r:
+pxefile_addr_r:
Mandatory. The location in RAM where extlinux.conf will be loaded to prior
to processing.
If you want to disable boot.scr on all disks, set the value to something
innocuous, e.g. setenv scan_dev_for_scripts true.
+boot_net_usb_start:
+
+ If you want to prevent USB enumeration by distro boot commands which execute
+ network operations, set the value to something innocuous, e.g. setenv
+ boot_net_usb_start true. This would be useful if you know your Ethernet
+ device is not attached to USB, and you wish to increase boot speed by
+ avoiding unnecessary actions.
+
+boot_net_pci_enum:
+
+ If you want to prevent PCI enumeration by distro boot commands which execute
+ network operations, set the value to something innocuous, e.g. setenv
+ boot_net_pci_enum true. This would be useful if you know your Ethernet
+ device is not attached to PCI, and you wish to increase boot speed by
+ avoiding unnecessary actions.
Interactively booting from a specific device at the u-boot prompt
=================================================================