[yocto] LINUX_VERSION issue in recipe

[Andre McCurdy]

On Fri, Apr 27, 2018 at 3:44 AM, Damien LEFEVRE <lefevre.da at gmail.com> wrote:
> Hi,
>
> This must be a stupid basic question. I have the following recipe append:
>
> keymaps_1.0.bbappend
> -----------------------------------------------------------------------------
> FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}:"
> SRC_URI_append = " file://keymaps.service \
>                    file://keymap.sh \
> "
>
> do_install_append() {
>     install -d ${D}${sysconfdir}
>     ln -sf /usr/share/keymaps/i386/qwerty/fi.map.gz
> ${D}${sysconfdir}/keymap-${LINUX_VERSION}.map.gz
>
>     install -d ${D}${systemd_system_unitdir}
>     install -m 0644 ${WORKDIR}/keymaps.service ${D}${systemd_system_unitdir}
> }
>
> FILES_${PN} += " ${sysconfdir}/* \
>                  ${systemd_system_unitdir}/* \
> "
>
> inherit systemd
> SYSTEMD_SERVICE_${PN} = "${PN}.service"
> -----------------------------------------------------------------------------
>
> The LINUX_VERSION is not expanded and the final symlink name becomes
> /etc/keymap-.map.gz.
>
> What's correct way to get the linux version in the recipe files?

In general, there isn't a correct way to do that. The LINUX_VERSION
variable is defined within the kernel recipe and other recipes won't
have access to it.

A core concept in OE is that recipes build independently of each
other. In this case, since the keymaps recipe has no direct dependency
on the kernel, you should not expect the keymaps recipe to be rebuilt
(or affected in any way) when the kernel or kernel version changes.

The keymaps init script ( meta/recipes-bsp/keymaps/files/keymap.sh )
detects the kernel version dynamically at runtime. If you need a
kernel version specific symlink in your target rootfs, maybe you could
create it at runtime from your keymaps service file?