This patch does probably too much, but it's hard (and very
cumbersome/time consuming) to break it out. What is does is this:
* each command has one short description, e.g. "list MUX configuration"
* made sure the short descriptions start lowercase
* each command has one usage. That string contains just the
options, e.g. "[-npn]". It's not part of the long help text.
* that is, it doesn't say "[OPTIONS]" anymore, every usable option
is listed by character in this (short) option string (the long
description is in the long help text, as before)
* help texts have been reworked, to make them
- sometimes smaller
- sometimes describe the options better
- more often present themselves in a nicer format
* all long help texts are now created with BUSYBOX_CMD_HELP_
macros, no more 'static const __maybe_unused char cmd_foobar_help[]'
* made sure the long help texts starts uppercase
* because cmdtp->name and cmdtp->opts together provide the new usage,
all "Usage: foobar" texts have been removed from the long help texts
* BUSYBOX_CMD_HELP_TEXT() provides the trailing newline by itself, this
is nicer in the source code
* BUSYBOX_CMD_HELP_OPT() provides the trailing newline by itself
* made sure no line gets longer than 77 characters
* delibertely renamed cmdtp->usage, so that we can get compile-time
errors (e.g. in out-of-tree modules that use register_command()
* the 'help' command can now always emit the usage, even without
compiled long help texts
* 'help -v' gives a list of commands with their short description, this
is similar like the old "help" command before my patchset
* 'help -a' gives out help of all commands
Signed-off-by: Holger Schurig <holgerschurig@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
The old output of "help" was just producing a long list, that usually
scrolled of the screen (even on a X11 terminal). This list is more
compact, and also sorted by groups.
The old output format (plus grouping) is now available with 'help -v'.
Example:
Information commands:
?, devinfo, help, iomem, meminfo, version
Boot commands:
boot, bootm, go, loadb, loads, loadx, loady, saves, uimage
...
Signed-off-by: Holger Schurig <holgerschurig@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
We use 'u32' type in stdlib.h so we have to include types.h.
Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Clock gates having the CLK_GATE_HIWORD_MASK flag set use the upper 16
bits of the register as a "write enable" mask for the value in the
lower 16 bits.
Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
This adds a clk_gate_flags argument to clock gate creation functions
to allow the introduction of new clock gate modifiers.
Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Provide minimal regulator support. Only supported operations are enabling
and disabling regulators. Association of devices with their regulators is
limited to devicetree only. If regulator support is disabled the API expands
to static inline stubs so consumers can still use the API.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
barebox used to have its own include/dt-bindings with files copied
from the corresponding kernel files. Use upstream dt-bindings directly
instead.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
When a mtd device can have bad blocks we want to create a
bb device, so do this automatically. This allows us to
drop bb device creation from the environment.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
This refactors the code so that we get a mtd_add_bb which can
be used to create a bb dev on a mtd_info.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
The purpose of envfs_register_partition is to print an error
message when the partition does not exist. Print an error message
from generic code instead and drop this function.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
The cast prevents us from doing proper error checking.
Signed-off-by: Lucas Stach <dev@lynxeye.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
The current implementation fakes a memory-mapped I/O device
at 0x3f8 and 0x2f8, then uses platform read/write functions
to do the actual reading and writing. These platform functions
only exist for the x86 platform; better to move the I/O
routines into the driver and have the driver request I/O ports
using request_ioport_region.
Signed-off-by: Michel Stam <michel@reverze.net>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Rework the current framework so that I/O mapped I/O resources are
also possible.
Signed-off-by: Michel Stam <michel@reverze.net>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
This adds a convenience function to register a MAC address device
parameter. The only current user is converted to use it.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
This is needed so that the IPU framebuffer scanout cannot be
starved by VPU or GPU activity.
Some boards like the SabreLite and SabreSD seem to set this in
the DCD already, but the documented register reset values do not
contain the necessary settings.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
We have dev_add_param_enum() now, so use it for the mode_name
setting. Also drop the special case for single mode framebuffers,
just add the mode_name parameter for this case aswell.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
And use it inside struct fb_info. This struct has the advantage
that the supported modes can be passed around in a single pointer.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
This updates the clk-divider to Kernel code, but without power-of-two
divider support which we do not need yet. This also adds table based
divider support to the divider.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Creating menus from the shell using the regular 'menu' command is rather
complicated. This adds a 'menutree' command which creates a menu from
a directory structure. In the directory structure each directory corresponds
to a single menu entry. The directory contains the following files:
title - A file containing the title of the entry as shown in the menu
box - If present, the entry is a 'bool' entry. The file contains a variable
name from which the current state of the bool is taken from and saved
to.
action - if present this file contains a shell script which is executed when
when the entry is selected.
If neither 'box' or 'action' are present this entry is considered a submenu
containing more entries.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Add DDR3 SPD verification support for use by the PPC 8xxx DDR driver.
This is based on the equivalent files from U-Boot version git-be937b5.
Signed-off-by: Renaud Barbier <renaud.barbier@ge.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
This macros are used in exported from linux TI DaVinci code.
Also this macros are used in MIPS cache support code.
Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
MTD internal API presently uses 32-bit values to represent device
size. This patch updates them to 64-bits but leaves the external API
unchanged.
In general, changing from 32-bit to 64-bit values cause little
or no changes to the majority of the code with the following
exceptions:
- printk message formats;
- division and modulus of 64-bit values (mtd_div_by_wb,
mtd_div_by_eb may be used in some of such cases).
Was tested on phyFLEX i.MX6.
Signed-off-by: Dmitry Lavnikevich <d.lavnikevich@sam-solutions.com>
Signed-off-by: Grigory Milev <g.milev@sam-solutions.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
The defaultenv-2 has ifup support as a shell script. This patch
replaces it with a command which is more robust, can be called
from C and now can also bring up all configured interfaces.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
The default nand_read_subpage implementation returns -ENOSUPP, so we have
to make sure that barebox never uses this implementation. By setting the
NAND_SUBPAGE_READ flag to 0x0 we ensure NAND_HAS_SUBPAGE_READ() never returns
true and also give the compiler a chance to optimize away some unused code.
subpage reads are a rather exotic feature even in Linux. It is only used on
largepage NANDs with soft ecc. Even if we have this case it needs non page
aligned reads to actually profit from this feature.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Hattink, Tjalling [FINT] <T.Hattink@fugro.nl>
Compared to devfs_add_partition which adds a single partition
devfs_create_partitions creates several partitions at once. One nice
benefit is that this simplifies appending partitions because the start
of the latter partition doesn't need to be specified explicitly.
Also dev_add_bb_dev() is called by the new helper if the bbname is
specified for a partition.
Note that adding partitions is also more flexible now (also via
devfs_add_partition) because negative values for offset and size now
have a proper meaning instead of creating broken partitions.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
The string pointed to isn't modified, so declare it as const.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
The value is only used to assign to a (*struct cdev)->flags which is an
unsigned int and it is passed as fourth parameter of mtd_add_partition which
is an unsigned long.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
We can compile barebox for multiple boards at once, but currently
they all share a single default environment. This patch adds a
defaultenv_append() which boards can call to customize the default
environment during runtime. Each board now generate default environment
snippets using bbenv-y and add them during runtime with defaultenv_append()
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Devicetrees specify the keyboard codes for the gpio-keys
driver, so add a table to translate them into something
barebox can use.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Currently the version defines reflect the digits in the version
number. MMC_VERSION_4_41 is defined as 0x441 and MMC_VERSION_4_5
is defined as 0x405. This results in MMC_VERSION_4_5 < MMC_VERSION_4_41
becoming true which was surely not intended. Fix this by
redefining the versions as 0x<major><minor><micro>. This makes the
string generation more complicated but makes versions comparable
again.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
- configure the MC34708 properly so that USB can work
(the sequence is taken from u-boot)
- add the required defines to the mc13xxx include file
Signed-off-by: Eric Bénard <eric@eukrea.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
This imports the Marvell mbus driver from Linux. The mbus is the
main downstream bus found on all Marvell Orion SoCs. The driver
deals with re-configurable address windows which are currently
parsed from DT. Also enable the driver as default on all MVEBU
SoCs. While at it, also reorder drivers/bus/{Kconfig,Makefile}
alphabetically.
Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
This implements a of_phy_device_connect to allow DT enabled drivers
to connect to a PHY device by using the PHY's DT node only. It
currently assumes that each PHY node is a child of the corresponding
mdio bus.
Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Similar to mount(8) the barebox command mount now supports passing a string
to the file system driver via -o.
This is used in the next commit to let the user specify port numbers for
nfs mounts.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
ntohl always converts 32 bits even on archs where sizeof(long) == 8.
"ntoh32" is a much more intuitive name here. Also the name of the 64 bit
variant that is also added isn't questionable.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
This is needed for nfs3 support as some types became bigger compared to
nfs2.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
On some architectures (e.g. alpha, amd64, arm64, ia64, s390x, mips64)
sizeof(ulong) is 8 which made net_read_uint32 actually read too much and
even returned the wrong value on big endian machines.
(Note the second issue isn't that critical though, because the only
architecture from the list above that uses big endian byte order is s390x
...)
Also change the argument to void * because the pointer is not necessarily
properly aligned.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
This allows to load all the lowlevel init code, including the
uncompressor, inside SRAM and not just the bare init part. This is
useful when pbl is used as a first-stage bootloader but is loaded by an
external firmware.
Signed-off-by: David Vincent <freesilicon@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
i2c/spi devices in the devicetree often come with a "vendor,device"
comaptible string. These do not match in barebox, so add a
device_match_of_modalias function which does exactly that.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Boards register a fixup for a phy without checking if phy support
is enabled. To fix compilation without phy support add a static
inline wrapper for phy_register_fixup_for_uid.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
default_environment_path only exists when CONFIG_ENV_HANDLING is enabled.
Boards would have to #ifdef this if they wanted to use
default_environment_path. Use accessor functions instead which can
be ifdeffed on a single place.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Linux specifies the linux,stdout-path property in the /chosen node
in the devicetree. Unfortunately this is ignored in most cases.
For cases in which barebox uses this property for its own use we
translate this into a Linux boot arg with:
- the console name provided by the serial driver
- the the instance from the 'serial' alias
- the baudrate from the actual baudrate.
So with this it's for devicetee enabled boards no longer necessary
to manually assign a console= parameter. Should a user not want
to use the automatically assigned parameter it should do:
global.linux.bootargs.console=
in the environment.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
The eMMC and the SD-Card specifications describe the optional SET_DSR command.
During measurements at our lab we found that some cards implementing this feature
having really strong driver strengts per default. This can lead to voltage peaks
above the specification of the host on signal edges for data sent from a card to
the host.
Since availability of a given card type may be shorter than the time a certain
hardware will be produced it is useful to have support for this command (Alternative
would be changing termination resistors and adapting the driver strength of the
host to the used card.)
Signed-off-by: Markus Niebel <Markus.Niebel@tqs.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
eMMC is available up to version 4.5 but the
correct version is not decoded. Change version
definitions to support more minor verions, add
missing versions and parse the minor versions from
ext_csd.
After this, card detection code and devinfo reports
correct versions.
Handling is inspired by u-boot code.
Signed-off-by: Markus Niebel <Markus.Niebel@tqs.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
The common bootm code used to load uImage contents to SDRAM
before calling into the handlers if possible. This makes the
handlers complicated since they have to handle many cases. Instead,
introduce a helper to load the os after the handlers have figured
out a good load address.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
This patch includes update i.MX51 template and porting some barebox
DTS files to use new template.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
miitool without arguments will try to show status for all phys.
Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
ubiformat needs the subpagesize to work correctly. The kernel uses
sysfs to pass the subpagesize, but in barebox we have the possibility
to extend struct mtd_info_user. Add a corresponding field and use it
in ubiformat.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
barebox does not need the screen size directly, but we pass the
framebuffer to Linux via simnplefb it is desirable to pass the
full size of the framebuffer. Default to calculated values from
the screen resolution.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Sometimes execution of a function has to be delayed, for example
when a backlight can only be turned on when the picture has stabilized.
To help in such situations add a convenience function around the poller
stuff to call a function after a delay.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
With this phy_device_connect only registers a phy device if it wasn't
registered already. This allows us to register phy devices outside
of ethernet drivers. phy_device_connect will now pick up an already
registered phy given that it's not attached to another ethernet device.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
If an ethernet device already has a phy in phy_device_connect all we
have to do is to start autonegotiation. Do this early and bail out
so that for the rest of the code it's clear that we have to search for
a phy device.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
This patch adds the crc32 command to be build
as host and optionally as target tool.
Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
We currently have functions to add a device based on function parameters.
This adds the corresponding functions to add resources to a device without
registering the device itself. This is useful to manipulate devices before
registering them.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Instead of requiring a device pointer, add a functions to select
the pinctrl state based on a device node.
The AM33xx cpsw devicetree description has several subdevices with
pinctrl information attached to them. In barebox we do not handle
the subdevices as distinct devices, so the pinctrl is never configured
correctly and the mdio bus subdevice stops working. This patch makes
it possible to configure the pinctrl without having a device.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Also import related functions gpio_request_one() and
gpio_free_array().
This commit imports code from linux 3.7 as
the more recent linux kernel versions use gpiolib descriptors,
see this commit for details:
commit 372e722ea4dd4ca11c3d04845e11cbc15f32144c
Author: Alexandre Courbot <acourbot@nvidia.com>
Date: Sun Feb 3 01:29:29 2013 +0900
gpiolib: use descriptors internally
Make sure gpiolib works internally with descriptors and (chip, offset)
pairs instead of using the global integer namespace. This prepares the
ground for the removal of the global gpio_desc[] array and the
introduction of the descriptor-based GPIO API.
Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
See linux.git/include/linux/gpio.h and
linux.git/Documentation/gpio.txt for details.
Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
The current implementation of the bootloader specification depends on the
hardware name and the name of the device in /dev to match. As the default
hardware name is mciX and the device name is diskY the bootloader spec
cannot be used as is.
This patch implements a way to overwrite the device name similar to what is
possible for the imx-esdhc driver.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
This add barebox versions of of_clk_init for parsing and registering
clock providers from DT. Also, a macro CLK_OF_DECLARE is added, that
allows to put init callbacks into its own section that can be linked
in the binary.
Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
This adds a macro for linker scripts to place DT clock provider table.
While at it, also add ALIGN(8) to DTB macro and fix a whitespace issue.
Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
At least for debugging purposes it is helpful to determine the current
direction for a given GPIO. Add a callback to gpiochip, to allow to
get it.
Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
A lot of files rely on include/driver.h including include/of.h (and
this including include/errno.h. include the files explicitly so we can
eventually get rid of including of.h from driver.h
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Add support to configure the active framebuffer for the kernel through
device tree.
Signed-off-by: Andre Heider <a.heider@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
If drivers want to fixup their specific instance they need some context
to know which instance they have to fixup.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Add support for framebuffers with noncontiguous horizontal lines.
Video drivers can set this value if the hardware requires it.
In case a driver does not set it, the current value of
xres * (bpp / 8) is used instead.
Signed-off-by: Andre Heider <a.heider@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
the cdev for a given directory can be determined by get_cdev_by_mountpath().
Use this function and remove the cdev argument from blspec_scan_directory().
Also, export the function to make code possible which boots the bootloader
spec entries found in directories.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
blspec->menu is only valid when menu support is enabled. Check for it
before dereferencing the pointer.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Right now we do not support persistent names for mtd devices. The
base name can be passed to add_mtd_device, but this is always appended
with a dynamic number. With this patch add_mtd_device takes a device_id
argument which can be used to create a mtd device with an exact name.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
KSZ8031 is similar to KSZ8021. It can use the same functions.
Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Some controller such as the ARM AMBA pl181 can not handle more than 16bits
data length request.
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
The macro can be used for temporary stack buffers which need to meet
a minimum alignment requirement.
This will be used by bcm2835 mailbox users, where all buffers need to
be aligned.
Signed-off-by: Andre Heider <a.heider@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Instead of populating an extra list containing all phandles just iterate
over the whole tree. This is done as preparation for more dynamic devicetrees
where parts are loaded at runtime. Here we don't want to keep the list of
phandles in sync.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
was not include when applying bpkfs patch
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
The Bootloader Specification describes a way how kernels can
be installed on devices and how they can be started by the bootloader.
The bootloader spec is currently supported by (x86) gummiboot and
by systemd which provides a kernel-install script. With the bootloader
spec it's possible for the Operating system to install a new kernel
without knowing about the bootloader and for the bootloader it's possible
to discover and start Operating Systems on a media without being
configured.
For more details about the spec see:
http://www.freedesktop.org/wiki/Specifications/BootLoaderSpec/
This patch adds barebox support for the spec. It enhances the 'boot'
command so that not only boot script names can be given, but also
devices containing bootloader spec entries. With this it's possible
to call the 'boot' command like: 'boot sd emmc net'. It would then
first look for bootloader spec entries on the (removable) sd card,
then, is nothing is found, on the internal emmc and if still
unsuccessful would call the 'net' bootscript.
The bootloader Spec currently doesn't specify which entry should be
default if multiple entries are found on a single device. Therefore
barebox currently has two extensions of the spec. The $BOOT diretory
can contain a file named 'default'. If present, the content of the
file is treated as a filename under $BOOT/loader/entries/ which is
used as default. Similarly if a file named 'once' is present, the
entry is started once and the file is removed afterwards. This is
useful for testing if a newly installed kernel works before making
it the default.
As on ARM and other Architectures a devicetree has to be specified
for the kernel, the 'devicetree' property is used to specify a
devicetree. Like 'kernel' and 'initrd' this also contains a pth
relative to $BOOT.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Often small files are used to store the value od a variable. This
adds a function to easily read such a variable.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>