Not all devices use the convention that the boot scripts are on the
first partition. For example on chromebooks it seems common for the
first two partitions to be ChromeOS kernel partitions.

So instead of just the first partition scan all partitions on a device
with a filesystem u-boot can recognize.

Signed-off-by: Sjoerd Simons <sjoerd.simons@collabora.co.uk>

Now that "usb start" will only start usb if not already started, we can simply
call "usb start" whenever we (may) need access to usb devices, and it will only
actually scan the bus at the first call.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>

Scsi disks need to be probed before we try to access them, otherwise all
accesses fail with: ** Bad device size - scsi 0 **.

Reported-by: Karsten Merker <merker@debian.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Karsten Merker <merker@debian.org>

This generic $bootcmd, and associated support macros, automatically
searches a defined set of storage devices (or network protocols) for an
extlinux configuration file or U-Boot boot script in various standardized
locations. Distros that install such a boot config file/script in those
standard locations will get easy-to-set-up booting on HW that enables
this generic $bootcmd.

Boards can define the set of devices from which boot is attempted, and
the order in which they are attempted. Users may later customize this
set/order by edting $boot_targets.

Users may interrupt the boot process and boot from a specific device
simply by executing e.g.:

$ run bootcmd_mmc1
or:
$ run bootcmd_pxe

This patch was originally written by Dennis Gilmore based on Tegra and
rpi_b boot scripts. I have made the following modifications since then:

* Boards must define the BOOT_TARGET_DEVICES macro in order to specify
  the set of devices (and order) from which to attempt boot. If needed,
  we can define a default directly in config_distro_bootcmd.h.

* Removed $env_import and related variables; nothing used them, and I
  think it's better for boards to pre-load an environment customization
  file using CONFIG_PREBOOT if they need.

* Renamed a bunch of variables to suit my whims:-)

Signed-off-by: Dennis Gilmore <dennis@ausil.us>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Marek Vasut <marex@denx.de>
Acked-by: Simon Glass <sjg@chromium.org>

This generic $bootcmd, and associated support macros, automatically
searches a defined set of storage devices (or network protocols) for an
extlinux configuration file or U-Boot boot script in various standardized
locations. Distros that install such a boot config file/script in those
standard locations will get easy-to-set-up booting on HW that enables
this generic $bootcmd.

Boards can define the set of devices from which boot is attempted, and
the order in which they are attempted. Users may later customize this
set/order by edting $boot_targets.

Users may interrupt the boot process and boot from a specific device
simply by executing e.g.:

$ run bootcmd_mmc1
or:
$ run bootcmd_pxe

This patch was originally written by Dennis Gilmore based on Tegra and
rpi_b boot scripts. I have made the following modifications since then:

* Boards must define the BOOT_TARGET_DEVICES macro in order to specify
  the set of devices (and order) from which to attempt boot. If needed,
  we can define a default directly in config_distro_bootcmd.h.

* Removed $env_import and related variables; nothing used them, and I
  think it's better for boards to pre-load an environment customization
  file using CONFIG_PREBOOT if they need.

* Renamed a bunch of variables to suit my whims:-)

Signed-off-by: Dennis Gilmore <dennis@ausil.us>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Marek Vasut <marex@denx.de>
Acked-by: Simon Glass <sjg@chromium.org>