4.20.x is not a long term support kernel, but 4.19.x is (supported until end
2020):
https://www.kernel.org/category/releases.html
With the upcoming Buildroot 2019.02 release being a LTS release, default to
4.19.x instead.
Notice: The userspace API breakage in net_stamp.h causing build failures has
now been fixed in 4.19.14 by commit e4a2ffe9029fd (net: Use
__kernel_clockid_t in uapi net_stamp.h)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
[Thomas: add comment in linux/Config.in and
package/linux-headers/Config.in.host so that we don't mistakenly bump
to 4.20+.]
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
This patch bumps the Linux CIP kernel to version v4.4.154-cip28
Signed-off-by: Angelo Compagnucci <angelo@amarulasolutions.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
This patch adds a simple way to change the linux bootup logo.
The patch was kept purposely simple to support only the use cause
where a user needs a color linux boot up logo.
Signed-off-by: Angelo Compagnucci <angelo@amarulasolutions.com>
Reviewed-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
[Peter: clarify/reword option/help text, automatically enable framebuffer
support, fix convert path]
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
This patch bumps the CIP Linux kernel to version v4.4.138-cip25
Signed-off-by: Angelo Compagnucci <angelo@amarulasolutions.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
This issue only applies to kernels built with CONFIG_THUMB2=y, so reword the
comment to make that more clear.
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
Commit f13477b (linux: config.in: add comment for Arm Cortex-M) added a
comment so that the user that the linux kernel may miscompile with
binutils 2.29+, when the target is an armv7m CPU.
However, the real trigger is a compilation in thumb2 mode, which happens
to be the only option for armv7m CPUs.
We can't know whether the kernel will be built in arm or thumb2 mode,
though, because we do not have that information: it is only available in
the Linux' .config file, which we don;t have access to at the time we
run our menuconfig.
So, relax the conditions under which the comment is made, so that it
appears as soon as binutils are >= 2.29 (i.e. not 2.28, which is the
oldest we support) for ARM CPUs.
[Peter: reword comment]
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Christophe Priouzeau <christophe.priouzeau@st.com>
Cc: Laurent GONZALEZ <br22@gezedo.com>
Cc: Peter Korsgaard <peter@korsgaard.com>
Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Cc: Arnout Vandecappelle <arnout@mind.be>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
This reverts commit cbe43fd417.
Now that the binutils default has been changed for ARMv7M, this is no longer
needed.
Signed-off-by: Christophe Priouzeau <christophe.priouzeau@st.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
When binutils > 2.28 are selected on Arm Cortex-M cpu,
linux kernel does not boot due to a new implementation
of 'adr pseudo instruction' on binutils.
Bugzilla thread: https://bugs.busybox.net/show_bug.cgi?id=11051
Signed-off-by: Christophe Priouzeau <christophe.priouzeau@st.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
This patch bump the Linux CIP kernel to version v4.4.130-cip23
Signed-off-by: Angelo Compagnucci <angelo@amarulasolutions.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
Just use whatever the user specified in the list. An empty list means no
DTS was specified.
No need to add legacy option, as the behaviour does not change.
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Simon van der Veldt <simon.vanderveldt@gmail.com>
Cc: Arnout Vandecappelle <arnout@mind.be>
Cc: Peter Korsgaard <peter@korsgaard.com>
Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Tested-by: Joshua Henderson <joshua.henderson@microchip.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
Some Linux kernel configuration options (such as CONFIG_UNWINDER_ORC)
require building a host program that needs libelf.
Users who have libelf installed on their system won't see a problem,
but users who don't have libelf installed will get a build
failure. Therefore, this commit adds an option that allows a user to
indicate that his Linux kernel configuration requires libelf. When
this option is enabled, we add host-elfutils to the dependencies of
the linux package (host-elfutils provides the libelf library).
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
Some Linux kernel configuration options (such as
CONFIG_SYSTEM_TRUSTED_KEYRING) require building a host program called
extract-cert, which itself needs OpenSSL.
Users having OpenSSL installed on their system won't see a problem,
but users who don't have OpenSSL installed will get a build
failure. This commit adds a new option that allows users to indicate
that their Linux configuration requires building host-openssl.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
For some boards, for example the Raspberry Pi, it's necessary to build
in-tree dts files as well as custom/out of tree dts-files (dt-blob.bin).
The existing logic made these two options exclusive, this commit changes
that to allow both in-tree as well as custom sources for dts files.
Signed-off-by: Simon van der Veldt <simon.vanderveldt@gmail.com>
[Arnout: re-wrap help, add extra empty line, change = into +=]
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
This patch bump the Linux CIP kernel to version v4.4.112-cip18
Signed-off-by: Angelo Compagnucci <angelo@amarulasolutions.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
This patch bumps the Linux CIP version to v4.4.105-cip15.
Signed-off-by: Angelo Compagnucci <angelo@amarulasolutions.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
This patch bump the Linux CIP kernel to version v4.4.98-cip13
Signed-off-by: Angelo Compagnucci <angelo@amarulasolutions.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
We don't add a full stop at the end of the prompt text.
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
A long time ago, the blind config option BR2_LINUX_KERNEL_UBOOT_IMAGE
was introduced to be able to trigger the linux -> host-uboot-tools
dependency. Back in those days, there was no user-configurable
BR2_PACKAGE_HOST_UBOOT_TOOLS.
Now, however, it is possible to select a custom kernel image name that
needs uboot-tools, and manually enable BR2_PACKAGE_HOST_UBOOT_TOOLS. In
this case, however, the linux -> host-uboot-tools is missed and the
build is not reproducible. An example of such a situation is the
upcoming CI40 defconfig.
As a solution, remove BR2_LINUX_KERNEL_UBOOT_IMAGE entirely. Instead,
just select BR2_PACKAGE_HOST_UBOOT_TOOLS and add the dependency if it
is selected.
Note that this may introduce a redundant dependency in case the user
selected BR2_PACKAGE_HOST_UBOOT_TOOLS for some other reason (e.g. to
be able to generate a U-Boot environment to include in the image, while
the kernel is built as a zImage). However, the redundant dependency
shouldn't hurt much.
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Cc: Abhimanyu Vishwakarma <abhimanyu.v@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
This patch adds an easy way to select the CIP project SLTS
kernel within the kernel menu.
Signed-off-by: Angelo Compagnucci <angelo.compagnucci@gmail.com>
[Thomas: remove BR2_CIP_KERNEL_REPO_URL option.]
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Starting with the release 2016.09 xtensa architecture is supported by
the U-Boot. Enable uimage target in xtensa linux kernel.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Fix commit 400eaa3452 ("linux: bump
default to version 4.10") in which a conflict was not correctly
resolved.
Reported-by: Romain Naour <romain.naour@smile.fr>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
The option `BR2_LINUX_KERNEL_CUSTOM_LOCAL` no longer exists (see commit
e782cd5b1b [1]); removing the option. Note
that this legacy option has already been handled (Config.in.legacy) in
the mentioned commit.
Signed-off-by: James Knight <james.knight@rockwellcollins.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
The kernel source tree also contains the sources for various userland
tools, of which cpupower, perf or selftests.
Currently, we have support for building those tools as part of the
kernel build procedure. This looked the correct thing to do so far,
because, well, they *are* part of the kernel source tree and some
really have to be the same version as the kernel that will run.
However, this is causing quite a non-trivial-to-break circular
dependency in some configurations. For example, this defconfig fails to
build (similar to the one reported by Paul):
BR2_arm=y
BR2_cortex_a7=y
BR2_ARM_FPU_NEON_VFPV4=y
BR2_TOOLCHAIN_EXTERNAL=y
BR2_INIT_SYSTEMD=y
BR2_LINUX_KERNEL=y
BR2_LINUX_KERNEL_CUSTOM_GIT=y
BR2_LINUX_KERNEL_CUSTOM_REPO_URL="https://github.com/raspberrypi/linux.git"
BR2_LINUX_KERNEL_CUSTOM_REPO_VERSION="26f3b72a9c049be10e6af196252283e1f6ab9d1f"
BR2_LINUX_KERNEL_DEFCONFIG="bcm2709"
BR2_PACKAGE_LINUX_TOOLS_CPUPOWER=y
BR2_PACKAGE_CRYPTODEV=y
BR2_PACKAGE_OPENSSL=y
BR2_PACKAGE_LIBCURL=y
This causes a circular dependency, as explained by Thomas:
- When libcurl is enabled, systemd depends on it
- When OpenSSL is enabled, obviously, will use it for SSL support
- When cryptodev-linux is enabled, OpenSSL will depend on it to use
crypto accelerators supported in the kernel via cryptodev-linux.
- cryptodev-linux being a kernel module, it depends on linux
- linux by itself (the kernel) does not depend on pciutils, but the
linux tool "cpupower" (managed in linux-tool-cpupower) depends on
pciutils
- pciutils depends on udev when available
- udev is provided by systemd.
And indeed, during the build, we can see that make warns (it's only
reported as a *warning*, not as an actual error):
[...]
make[1]: Circular /home/ymorin/dev/buildroot/O/build/openssl-1.0.2h/.stamp_configured
<- cryptodev-linux dependency dropped.
>>> openssl 1.0.2h Downloading
[...]
So the build fails later on, when openssl is actually built:
eng_cryptodev.c:57:31: fatal error: crypto/cryptodev.h: No such file or directory
compilation terminated.
<builtin>: recipe for target 'eng_cryptodev.o' failed
Furthermore, graph-depends also detects the circular dependency, but
treats it as a hard-error:
Recursion detected for : cryptodev-linux
which is a dependency of: openssl
which is a dependency of: libcurl
which is a dependency of: systemd
which is a dependency of: udev
which is a dependency of: pciutils
which is a dependency of: linux
which is a dependency of: cryptodev-linux
Makefile:738: recipe for target 'graph-depends' failed
Of course, there is no way to break the loop without losing
functionality in either one of the involved packages *and* keep
our infrastructure and packages as-is.
The only solution is to break the loop at the linux-tools level, by
moving them away into their own package, so that the linux package will
no longer have the opportunity to depend on another package via a
dependency of one the tools.
All three linux tools are thus moved away to their own package.
The package infrastructure only knows of three types of packages: those
in package/ , in boot/ , in toolchain/ and the one in linux/ . So we
create that new linux-tools package in package/ so that we don't have to
fiddle with yet another special case in the infra. Still, we want its
configure options to appear in the kernel's sub-menu.
So, we make it a prompt-less package, with only the tools visible as
options of that package, but without the usual dependency on their
master symbol; they only depend on the Linux kernel.
Furthermore, because the kernel is such a huge pile of code, we would
not be very happy to extract it a second time just for the sake of a few
tools. We can't extract only the tools/ sub-directory from the kernel
source either, because some tools have hard-coded path to includes from
the kernel (arch and stuff).
Instead, we just use the linux source tree as our own build tree, and
ensure the linux tree is extracted and patched before linux-tools is
configured and built.
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Paul Ashford <paul.ashford@zurria.co.uk>
[Thomas:
- fix typo #(@D) -> $(@D)
- fix the inclusion of the per-tool .mk files.]
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
It's been deprecated for quite some time now.
Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
This reverts commit 73da2ff6f7.
The reason for adding support for a local location was to be able to do
development on the Linux kernel source tree on a local directory rather
than have to clone it for every build.
We already have a mechanism for that, it's called override-srcdir. It's
been available since September 2011, more than a year before this patch
was committed.
Otherwise, we're going to be adding support for local sources in other
packages. First was U-Boot as submitted by Adam. But what next? We can't
have such support for all packages, especially since override-srcdir
does the job.
Besides, using a local source tree makes the build non-reproducible, so
we don't really want to have this in a .config (or defconfig).
We only handle the boolean option in legacy, as there is nothing we can
do with the directory path.
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Rafal Fabich <rafal.fabich@gmail.com>
Cc: Peter Korsgaard <peter@korsgaard.com>
Cc: Arnout Vandecappelle <arnout@mind.be>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Adam Duskett <aduskett@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
To configure the Linux kernel, we currently provide two options:
1. Passing a defconfig name (for example "multi_v7"), to which we append
"_defconfig" to run "make multi_v7_defconfig".
2. Passing a path to a custom configuration file.
Unfortunately, those two possibilities do not allow to configure the
kernel when you want to use the default configuration built into the
kernel for a given architecture. For example, on ARM64, there is a
single defconfig simply called "defconfig", which you can load by
running "make defconfig".
Using the mechanism (1) above doesn't work because we append
"_defconfig" automatically.
One solution would be to change (1) and require the user to enter the
full defconfig named (i.e "multi_v7_defconfig" instead of "multi_v7"),
but we would break all existing Buildroot configurations.
So instead, we add a third option, which simply tells Buildroot to use
the default configuration for the selected architecture. In this case,
Buildroot will configure the kernel by running "make defconfig".
Cc: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
When setting BR2_LINUX_KERNEL_LATEST_VERSION, it is hard for the user to
know that this version is subject to change in the future.
Explicit this in the Kconfig entry text.
Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Acked-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Since quite some time, the kernel and bootloader communities consider
zImage as the default format for kernel images on ARM, replacing
uImage. The load address information in uImage is no longer needed,
since the kernel is position-independent in terms of physical address,
except on a few old platforms. For most people, using zImage is simply
better/simpler, so let's switch to zImage as the default image format
on ARM.
All defconfigs are updated: 46 defconfigs no longer need to select
explicitly zImage because it's the default, and 16 defconfigs now need
to explicitly select uImage because that's no longer the default.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Reviewed-by: Matt Weber <matt@thewebers.ws>
Acked-by: Julien Boibessot <julien.boibessot@armadeus.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
It is no longer meaningful, now that we have the option to use the
kernel version for the linux headers, as it is more logical and more
versatile.
Add it to legacy.
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Peter Korsgaard <peter@korsgaard.com>
Cc: Arnout Vandecappelle <arnout@mind.be>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Some heavily (and most often improperly) modified Linux kernels may export
new APIs to userland, so as to speak to custom hardware or custom kernel
facilities.
However, we currently have no easy way to use such kernels as a source
for the linux-headers package, which precludes having those userland
headers intalled for userland applications to use them.
We do have a way for the kernel to use the same version as for the
headers, but that is definitely not enough, as the linux-headers package
has a version choice that is far less versatile and capable than that of
the linux package.
Add a new option for the linux-headers package, for the user to specify
that the version (really, the sources) of the kernel be used to install
the headers from.
We do that by making linux-headers patch-depend on the linux package.
We can't have linux-header simply depend on linux, because the simple
dependency means the the dependee will be configured, built and installed
before the dependent is configured. And since linux is a target package,
it depends on the toolchain, which internally dependes on linux-headers,
which would depend on linux, and we'd get a circular dependency.
Using patch-depend will ensure that linux is extracted and patched
before linux-headers is extracted, which is really all we need.
Then, we install the headers from the linux source tree, rather than
from linux-headers' source tree (as there's nothing in there!).
Since we need to install a private set for uClibc (see cde947f, uclibc:
prevent rebuilding after installation to staging), we explicitly set
INSTALL_HDR_PATH when calling the kernel' install-headers rule in
LINUX_HEADERS_CONFIGURE_CMDS, so that the headers are installed in
linux-headers' $(@D) instead of linux' $(@D).
Finally, as there is no way to know the kernel version in this case, we
must still prompt the user for the kernel series the headers are from
(like we do for a custom version) and check for consistency at build
time.
Note however that this still leaves users that want to built their
such-kernel outside of Buildroot out in the cold.
[Peter: drop comment as suggested by Thomas]
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Karoly Kasza <kaszak@gmail.com>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Peter Korsgaard <jacmet@uclibc.org>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
Currently, packages that need the kernel to have support for laodable
modules have two ways to require it:
- either the use the kernel-module infra, which does it automatically,
- or they do not use it, and they need to require it manually by
setting the corresponding Makefile variable; however, they must only
set it when they are actually enabled, which makes for a slightly
cumbersome and ugly code, like:
ifeq ($(BR2_PACKAGE_FOO),y)
LINUX_NEEDS_MODULES = y
endif
Introduce a new blind Kconfig option that packages can select to signify
they need kernel modules. That Kconfig option is then used to set the
Makefile variable.
It makes it cleaner:
- code is simpler (one Kconfig line instead of a Makefile if-block,
- this is handled at the Kconfig level, which is where we usually
handle such dependencies.
Packages will be updated in follow-up commits.
Reported-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
Linux for MIPS supports raw binary zboot image (vmlinuz.bin).
Add it to the "Kernel binary format" list.
Signed-off-by: Yegor Yefremov <yegorslists@googlemail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
This selection will ensure that the correct host tools
will be build used for the kernel compression method used.
[Maxime: Select the compression opts in the kernel config too ]
Signed-off-by: Sagaert Johan <sagaert.johan@proximus.be>
Signed-off-by: Maxime Hadjinlian <maxime.hadjinlian@gmail.com>
Reviewed-by: "Yann E. MORIN" <yann.morin.1998 at free.fr>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
On aarch64, the image name is always Image, so let's add support for
that.
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
This patch is based on the patch send by James Knight:
http://lists.busybox.net/pipermail/buildroot/2015-May/128754.html
Signed-off-by: Romain Naour <romain.naour@openwide.fr>
Cc: James Knight <james.knight@rockwellcollins.com>
Reviewed-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
linux has uImage generation support for powerpc64 as well as powerpc,
since 2.6.15.
Signed-off-by: Erico Nunes <erico.nunes@datacom.ind.br>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
[Thomas: fix issues noticed by Arnout:
- Rewrap the linux/Config.in paragraph
- Revert the "is a toolchain dependency" -> "has a toolchain
dependency" change from pkg-generic.mk, as the original was
correct.]
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Several packages have some logic to apply custom patches that existed
before the BR2_GLOBAL_PATCH_DIR mechanism: at91bootstrap,
at91bootstrap3, barebox, uboot and linux. Currently, the logic of
those packages to apply custom patches is to match
<package-name>-*.patch, which is not consistent with what we've done
for patches stored in the package directory, and for patches stored in
BR2_GLOBAL_PATCH_DIR: in such cases, we simply apply *.patch.
Therefore, for consistency reasons, this commit changes these packages
to also apply *.patch.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Reviewed-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Since BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE can either be a complete
.config file or a defconfig file, it can be confusing to the user
whether to choose BR2_LINUX_KERNEL_USE_DEFCONFIG or
BR2_LINUX_KERNEL_USE_CUSTOM_CONFIG.
To avoid that confusion, clarify Kconfig entry messages for in-tree
defconfig and custom (def)config files.
Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Acked-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
The help text for Linux option 'Custom tarball' only refers to ftp or
http tarballs, while in reality file or scp protocols are also
supported.
Triggered by a recent support question, update the help text to clarify
this.
Signed-off-by: Thomas De Schampheleire <thomas.de.schampheleire@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>