Yocto: BitBake and Dependencies - e.g. One recipe to use output of another recipe

- 
It feels weird to help some get their working
build to fail and then for them to be happy
about it... (RP)

Introduction

This work is sponsored by Reliable Embedded Systems. You can find more information about our training/consulting services here.



Objectives

The goal of this blog post is to look into BitBake dependencies. As an example let's take recipe A (u-boot-phytex-imx) which needs the output of recipe B (firmware-imx-8m) for a successful compilation. (Please don't ask why.)

To be more precise here is an excerpt of recipe A (u-boot-phytex-imx):

# --> this funny u-boot from Phytec needs the ddr_firmware binaries in ${S}
# Note: here we copy deployed stuff from another recipe
#       to the source dir of this recipe!
#
# DEPENDS deals with build-time depenencies
# Read my blog post to find out why DEPENDS does not work here
#
# DEPENDS += " \
#           firmware-imx-8m \
#           "
# RDEPENDS is wrong anyhow for what I want it,
# since it deals with runtime dependencies
#
# RDEPENDS_${PN} += "firmware-imx-8m"
#
# this works:
#
do_compile[depends] = "firmware-imx-8m:do_deploy"

do_compile_prepend() {
    bbnote 8MQ/8MM/8MN firmware
    for ddr_firmware in ${DDR_FIRMWARE_NAME}; do
        bbnote "Copy ddr_firmware: ${ddr_firmware} from ${DEPLOY_DIR_IMAGE} -> ${S} "
        cp ${DEPLOY_DIR_IMAGE}/${ddr_firmware}               ${S}
    done
}
# <-- this funny u-boot from Phytec needs the ddr_firmware binaries in ${S}

Dependencies

RDEPENDS

You could try something like that: 

RDEPENDS_${PN} += "firmware-imx-8m"

but this is most definitely wrong, since RDEPENDS deal with runtime dependencies. Like this the u-boot-phytex-imx recipe would tell the package manager to install the firmware-imx-8m package as well which is not what we want here and also it does not make much sense.

That's what the BitBake Manual says:

RDEPENDS

Lists a package's runtime dependencies (i.e. other packages) that must be installed in order for the built package to run correctly. If a package in this list cannot be found during the build, you will get a build error.

Because the RDEPENDS variable applies to packages being built, you should always use the variable in a form with an attached package name. For example, suppose you are building a development package that depends on the perl package. In this case, you would use the following RDEPENDS statement: 

     RDEPENDS_${PN}-dev += "perl"

In the example, the development package depends on the perl package. Thus, the RDEPENDS variable has the ${PN}-dev package name as part of the variable.

BitBake supports specifying versioned dependencies. Although the syntax varies depending on the packaging format, BitBake hides these differences from you. Here is the general syntax to specify versions with the RDEPENDS variable: 

     RDEPENDS_${PN} = "package (operator version)"

For operator, you can specify the following: 

     =
     <
     >
     <=
     >=

For example, the following sets up a dependency on version 1.2 or greater of the package foo: 

     RDEPENDS_${PN} = "foo (>= 1.2)"

For information on build-time dependencies, see the DEPENDS variable.

DEPENDS

You could try something like that: 

DEPENDS += " \
           firmware-imx-8m \
           "

That's most likely what most people would try and they would be surprised if it doesn't work.

That's what the BitBake Manual says:

DEPENDS

Lists a recipe's build-time dependencies (i.e. other recipe files).

Consider this simple example for two recipes named "a" and "b" that produce similarly named packages. In this example, the DEPENDS statement appears in the "a" recipe: 

     DEPENDS = "b"

Here, the dependency is such that the do_configure task for recipe "a" depends on the do_populate_sysroot task of recipe "b". This means anything that recipe "b" puts into sysroot is available when recipe "a" is configuring itself.

For information on runtime dependencies, see the RDEPENDS variable.

Let's give it a try:

Despite the fact that my friend and our beloved chief system architect RP does not quite understand why it would make me happy to break my build he successfully helped me to break it, so I can show these things here:

pokyuser@862ca11939a7:/workdir/build$ bitbake firmware-imx-8m -c clean; bitbake u-boot-phytec-imx -c clean; bitbake u-boot-phytec-imx -c compile
NOTE: Started PRServer with DBfile: /workdir/build/phyboard-polis-imx8mm-wic/cache/prserv.sqlite3, IP: 127.0.0.1, PORT: 40609, PID: 13422
Loading cache: 100% |#########################################################################################################################################| Time: 0:00:00
Loaded 3385 entries from dependency cache.
Parsing recipes: 100% |#######################################################################################################################################| Time: 0:00:00
Parsing of 2275 .bb files complete (2274 cached, 1 parsed). 3386 targets, 210 skipped, 2 masked, 0 errors.
NOTE: Resolving any missing task queue dependencies

Build Configuration:
BB_VERSION           = "1.46.0"
BUILD_SYS            = "x86_64-linux" 
NATIVELSBSTRING      = "universal"
TARGET_SYS           = "aarch64-resy-linux"
MACHINE              = "phyboard-polis-imx8mm"
DISTRO               = "resy"
DISTRO_VERSION       = "3.1.2"
TUNE_FEATURES        = "aarch64 armv8a crc crypto"
TARGET_FPU           = ""
meta
meta-poky
meta-yocto-bsp       = "2020-08-28-dunfell-3.1.2+:d3d80fa6fbf15189f6183a33c95fa90053535ae2"
meta-resy            = "dunfell:2968f06c1e400131e15bd726808a43195eec8c16"
meta-freescale       = "2020-08-28-dunfell:3fc701d11b4b096ba016110c83fe1b48c5f3a256"
meta-phyboard-polis-imx8mm-bsp = "v5.8.x-upstream:e1aaa104ab7879cd1b8f9272aafd06c24691ccb5"
meta-oe
meta-python
meta-networking      = "2020-04-30-dunfell-3.1:17fd382f3467e20308924499b7531ae8b789f056"

Initialising tasks: 100% |####################################################################################################################################| Time: 0:00:00
Sstate summary: Wanted 0 Found 0 Missed 0 Current 0 (0% match, 0% complete)
NOTE: No setscene tasks
NOTE: Executing Tasks
NOTE: Tasks Summary: Attempted 1 tasks of which 0 didn't need to be rerun and all succeeded.
NOTE: Writing buildhistory
NOTE: Writing buildhistory took: 0 seconds
NOTE: Started PRServer with DBfile: /workdir/build/phyboard-polis-imx8mm-wic/cache/prserv.sqlite3, IP: 127.0.0.1, PORT: 43644, PID: 13587
Loading cache: 100% |#########################################################################################################################################| Time: 0:00:00
Loaded 3385 entries from dependency cache.
Parsing recipes: 100% |#######################################################################################################################################| Time: 0:00:00
Parsing of 2275 .bb files complete (2274 cached, 1 parsed). 3386 targets, 210 skipped, 2 masked, 0 errors.
NOTE: Resolving any missing task queue dependencies

Build Configuration:
BB_VERSION           = "1.46.0"
BUILD_SYS            = "x86_64-linux" 
NATIVELSBSTRING      = "universal"
TARGET_SYS           = "aarch64-resy-linux"
MACHINE              = "phyboard-polis-imx8mm"
DISTRO               = "resy"
DISTRO_VERSION       = "3.1.2"
TUNE_FEATURES        = "aarch64 armv8a crc crypto"
TARGET_FPU           = ""
meta
meta-poky
meta-yocto-bsp       = "2020-08-28-dunfell-3.1.2+:d3d80fa6fbf15189f6183a33c95fa90053535ae2"
meta-resy            = "dunfell:2968f06c1e400131e15bd726808a43195eec8c16"
meta-freescale       = "2020-08-28-dunfell:3fc701d11b4b096ba016110c83fe1b48c5f3a256"
meta-phyboard-polis-imx8mm-bsp = "v5.8.x-upstream:e1aaa104ab7879cd1b8f9272aafd06c24691ccb5"
meta-oe
meta-python
meta-networking      = "2020-04-30-dunfell-3.1:17fd382f3467e20308924499b7531ae8b789f056"

Initialising tasks: 100% |####################################################################################################################################| Time: 0:00:00
Sstate summary: Wanted 0 Found 0 Missed 0 Current 0 (0% match, 0% complete)
NOTE: No setscene tasks
NOTE: Executing Tasks
NOTE: Tasks Summary: Attempted 1 tasks of which 0 didn't need to be rerun and all succeeded.
NOTE: Writing buildhistory
NOTE: Writing buildhistory took: 0 seconds
NOTE: Started PRServer with DBfile: /workdir/build/phyboard-polis-imx8mm-wic/cache/prserv.sqlite3, IP: 127.0.0.1, PORT: 33230, PID: 13752
Loading cache: 100% |#########################################################################################################################################| Time: 0:00:00
Loaded 3385 entries from dependency cache.
Parsing recipes: 100% |#######################################################################################################################################| Time: 0:00:00
Parsing of 2275 .bb files complete (2274 cached, 1 parsed). 3386 targets, 210 skipped, 2 masked, 0 errors.
NOTE: Resolving any missing task queue dependencies

Build Configuration:
BB_VERSION           = "1.46.0"
BUILD_SYS            = "x86_64-linux" 
NATIVELSBSTRING      = "universal"
TARGET_SYS           = "aarch64-resy-linux"
MACHINE              = "phyboard-polis-imx8mm"
DISTRO               = "resy"
DISTRO_VERSION       = "3.1.2"
TUNE_FEATURES        = "aarch64 armv8a crc crypto"
TARGET_FPU           = ""
meta
meta-poky
meta-yocto-bsp       = "2020-08-28-dunfell-3.1.2+:d3d80fa6fbf15189f6183a33c95fa90053535ae2"
meta-resy            = "dunfell:2968f06c1e400131e15bd726808a43195eec8c16"
meta-freescale       = "2020-08-28-dunfell:3fc701d11b4b096ba016110c83fe1b48c5f3a256"
meta-phyboard-polis-imx8mm-bsp = "v5.8.x-upstream:e1aaa104ab7879cd1b8f9272aafd06c24691ccb5"
meta-oe
meta-python
meta-networking      = "2020-04-30-dunfell-3.1:17fd382f3467e20308924499b7531ae8b789f056"

Initialising tasks: 100% |####################################################################################################################################| Time: 0:00:00
Sstate summary: Wanted 3 Found 3 Missed 0 Current 100 (100% match, 100% complete)
NOTE: Executing Tasks
ERROR: u-boot-phytec-imx-v2019.04-1.1.0-phy5+gitAUTOINC+6567aa7d61-r0 do_compile: Execution of '/workdir/build/phyboard-polis-imx8mm-wic/tmp/work/phyboard_polis_imx8mm-resy-linux/u-boot-phytec-imx/v2019.04-1.1.0-phy5+gitAUTOINC+6567aa7d61-r0/temp/run.do_compile.14116' failed with exit code 1:
cp: cannot stat '/workdir/build/phyboard-polis-imx8mm-wic/tmp/deploy/images/phyboard-polis-imx8mm/lpddr4_pmu_train_1d_imem.bin': No such file or directory
WARNING: /workdir/build/phyboard-polis-imx8mm-wic/tmp/work/phyboard_polis_imx8mm-resy-linux/u-boot-phytec-imx/v2019.04-1.1.0-phy5+gitAUTOINC+6567aa7d61-r0/temp/run.do_compile.14116:1 exit 1 from 'cp /workdir/build/phyboard-polis-imx8mm-wic/tmp/deploy/images/phyboard-polis-imx8mm/${ddr_firmware} /workdir/build/phyboard-polis-imx8mm-wic/tmp/work/phyboard_polis_imx8mm-resy-linux/u-boot-phytec-imx/v2019.04-1.1.0-phy5+gitAUTOINC+6567aa7d61-r0/git'

ERROR: Logfile of failure stored in: /workdir/build/phyboard-polis-imx8mm-wic/tmp/work/phyboard_polis_imx8mm-resy-linux/u-boot-phytec-imx/v2019.04-1.1.0-phy5+gitAUTOINC+6567aa7d61-r0/temp/log.do_compile.14116
Log data follows:
| DEBUG: Executing shell function do_compile
| NOTE: 8MQ/8MM/8MN firmware
| NOTE: Copy ddr_firmware: lpddr4_pmu_train_1d_imem.bin from /workdir/build/phyboard-polis-imx8mm-wic/tmp/deploy/images/phyboard-polis-imx8mm -> /workdir/build/phyboard-polis-imx8mm-wic/tmp/work/phyboard_polis_imx8mm-resy-linux/u-boot-phytec-imx/v2019.04-1.1.0-phy5+gitAUTOINC+6567aa7d61-r0/git
| cp: cannot stat '/workdir/build/phyboard-polis-imx8mm-wic/tmp/deploy/images/phyboard-polis-imx8mm/lpddr4_pmu_train_1d_imem.bin': No such file or directory
| WARNING: /workdir/build/phyboard-polis-imx8mm-wic/tmp/work/phyboard_polis_imx8mm-resy-linux/u-boot-phytec-imx/v2019.04-1.1.0-phy5+gitAUTOINC+6567aa7d61-r0/temp/run.do_compile.14116:1 exit 1 from 'cp /workdir/build/phyboard-polis-imx8mm-wic/tmp/deploy/images/phyboard-polis-imx8mm/${ddr_firmware} /workdir/build/phyboard-polis-imx8mm-wic/tmp/work/phyboard_polis_imx8mm-resy-linux/u-boot-phytec-imx/v2019.04-1.1.0-phy5+gitAUTOINC+6567aa7d61-r0/git'
| ERROR: Execution of '/workdir/build/phyboard-polis-imx8mm-wic/tmp/work/phyboard_polis_imx8mm-resy-linux/u-boot-phytec-imx/v2019.04-1.1.0-phy5+gitAUTOINC+6567aa7d61-r0/temp/run.do_compile.14116' failed with exit code 1:
| cp: cannot stat '/workdir/build/phyboard-polis-imx8mm-wic/tmp/deploy/images/phyboard-polis-imx8mm/lpddr4_pmu_train_1d_imem.bin': No such file or directory
| WARNING: /workdir/build/phyboard-polis-imx8mm-wic/tmp/work/phyboard_polis_imx8mm-resy-linux/u-boot-phytec-imx/v2019.04-1.1.0-phy5+gitAUTOINC+6567aa7d61-r0/temp/run.do_compile.14116:1 exit 1 from 'cp /workdir/build/phyboard-polis-imx8mm-wic/tmp/deploy/images/phyboard-polis-imx8mm/${ddr_firmware} /workdir/build/phyboard-polis-imx8mm-wic/tmp/work/phyboard_polis_imx8mm-resy-linux/u-boot-phytec-imx/v2019.04-1.1.0-phy5+gitAUTOINC+6567aa7d61-r0/git'
|
ERROR: Task (/workdir/sources/poky/../meta-phyboard-polis-imx8mm-bsp/recipes-bsp/u-boot/u-boot-phytec-imx_2019.04.bb:do_compile) failed with exit code '1'
NOTE: Tasks Summary: Attempted 459 tasks of which 453 didn't need to be rerun and 1 failed.
NOTE: The errors for this build are stored in /workdir/build/phyboard-polis-imx8mm-wic/tmp/log/error-report/error_report_20200907151617.txt
You can send the errors to a reports server by running:
  send-error-report /workdir/build/phyboard-polis-imx8mm-wic/tmp/log/error-report/error_report_20200907151617.txt [-s server]
NOTE: The contents of these logs will be posted in public if you use the above command with the default server. Please ensure you remove any identifying or proprietary information when prompted before sending.  
NOTE: Writing buildhistory
NOTE: Writing buildhistory took: 0 seconds

Summary: 1 task failed:
  /workdir/sources/poky/../meta-phyboard-polis-imx8mm-bsp/recipes-bsp/u-boot/u-boot-phytec-imx_2019.04.bb:do_compile
Summary: There was 1 ERROR message shown, returning a non-zero exit code.
pokyuser@862ca11939a7:/workdir/build$ bitbake firmware-imx-8m -e | grep ^T=
T="/workdir/build/phyboard-polis-imx8mm-wic/tmp/work/aarch64-mx8mm-resy-linux/firmware-imx-8m/8.5-r0/temp"
pokyuser@862ca11939a7:/workdir/build$ cat /workdir/build/phyboard-polis-imx8mm-wic/tmp/work/aarch64-mx8mm-resy-linux/firmware-imx-8m/8.5-r0/temp/log.
log.do_deploy_source_date_epoch_setscene        log.do_populate_sysroot_setscene                log.task_order
log.do_deploy_source_date_epoch_setscene.13814  log.do_populate_sysroot_setscene.13789

This build breaks because it cannot copy the ddr firmware from DEPLOY_DIR_IMAGE to wherever u-boot needs it. 

Why? Because, as we can see at the end of the previous shell session, do_populate_sysroot_setscene and do_deploy_source_date_epoch_setscene were executed, but nothing like do_deploy_setscene, which is what we need.

We can see that in the log files as well as the doc indicates something along those lines.

[depends] Inter-Task Dependencies

You could try something like that: 

do_compile[depends] = "firmware-imx-8m:do_deploy"

That's what the BitBake Manual says:

Inter-Task Dependencies

BitBake uses the [depends] flag in a more generic form to manage inter-task dependencies. This more generic form allows for inter-dependency checks for specific tasks rather than checks for the data in DEPENDS. Here is an example: 

     do_patch[depends] = "quilt-native:do_populate_sysroot"

In this example, the do_populate_sysroot task of the target quilt-native must have completed before the do_patch task can execute.

The [rdepends] flag works in a similar way but takes targets in the runtime namespace instead of the build-time dependency namespace.

Let's give it a try:

pokyuser@862ca11939a7:/workdir/build$ bitbake firmware-imx-8m -c clean; bitbake u-boot-phytec-imx -c clean; bitbake u-boot-phytec-imx -c compile                             NOTE: Started PRServer with DBfile: /workdir/build/phyboard-polis-imx8mm-wic/cache/prserv.sqlite3, IP: 127.0.0.1, PORT: 40834, PID: 23027
Loading cache: 100% |#########################################################################################################################################| Time: 0:00:00
Loaded 3385 entries from dependency cache.
Parsing recipes: 100% |#######################################################################################################################################| Time: 0:00:00
Parsing of 2275 .bb files complete (2274 cached, 1 parsed). 3386 targets, 210 skipped, 2 masked, 0 errors.
NOTE: Resolving any missing task queue dependencies

Build Configuration:
BB_VERSION           = "1.46.0"
BUILD_SYS            = "x86_64-linux"
NATIVELSBSTRING      = "universal"
TARGET_SYS           = "aarch64-resy-linux"
MACHINE              = "phyboard-polis-imx8mm"
DISTRO               = "resy"
DISTRO_VERSION       = "3.1.2"
TUNE_FEATURES        = "aarch64 armv8a crc crypto"
TARGET_FPU           = ""
meta
meta-poky
meta-yocto-bsp       = "2020-08-28-dunfell-3.1.2+:d3d80fa6fbf15189f6183a33c95fa90053535ae2"
meta-resy            = "dunfell:2968f06c1e400131e15bd726808a43195eec8c16"
meta-freescale       = "2020-08-28-dunfell:3fc701d11b4b096ba016110c83fe1b48c5f3a256"
meta-phyboard-polis-imx8mm-bsp = "v5.8.x-upstream:e1aaa104ab7879cd1b8f9272aafd06c24691ccb5"
meta-oe
meta-python
meta-networking      = "2020-04-30-dunfell-3.1:17fd382f3467e20308924499b7531ae8b789f056"

Initialising tasks: 100% |####################################################################################################################################| Time: 0:00:00
Sstate summary: Wanted 0 Found 0 Missed 0 Current 0 (0% match, 0% complete)
NOTE: No setscene tasks
NOTE: Executing Tasks
NOTE: Tasks Summary: Attempted 1 tasks of which 0 didn't need to be rerun and all succeeded.
NOTE: Writing buildhistory
NOTE: Writing buildhistory took: 0 seconds
NOTE: Started PRServer with DBfile: /workdir/build/phyboard-polis-imx8mm-wic/cache/prserv.sqlite3, IP: 127.0.0.1, PORT: 45439, PID: 23192
Loading cache: 100% |#########################################################################################################################################| Time: 0:00:00
Loaded 3385 entries from dependency cache.
Parsing recipes: 100% |#######################################################################################################################################| Time: 0:00:00
Parsing of 2275 .bb files complete (2274 cached, 1 parsed). 3386 targets, 210 skipped, 2 masked, 0 errors.
NOTE: Resolving any missing task queue dependencies

Build Configuration:
BB_VERSION           = "1.46.0"
BUILD_SYS            = "x86_64-linux" 
NATIVELSBSTRING      = "universal"
TARGET_SYS           = "aarch64-resy-linux"
MACHINE              = "phyboard-polis-imx8mm"
DISTRO               = "resy"
DISTRO_VERSION       = "3.1.2"
TUNE_FEATURES        = "aarch64 armv8a crc crypto"
TARGET_FPU           = ""
meta
meta-poky
meta-yocto-bsp       = "2020-08-28-dunfell-3.1.2+:d3d80fa6fbf15189f6183a33c95fa90053535ae2"
meta-resy            = "dunfell:2968f06c1e400131e15bd726808a43195eec8c16"
meta-freescale       = "2020-08-28-dunfell:3fc701d11b4b096ba016110c83fe1b48c5f3a256"
meta-phyboard-polis-imx8mm-bsp = "v5.8.x-upstream:e1aaa104ab7879cd1b8f9272aafd06c24691ccb5"
meta-oe
meta-python
meta-networking      = "2020-04-30-dunfell-3.1:17fd382f3467e20308924499b7531ae8b789f056"

Initialising tasks: 100% |####################################################################################################################################| Time: 0:00:00
Sstate summary: Wanted 0 Found 0 Missed 0 Current 0 (0% match, 0% complete)
NOTE: No setscene tasks
NOTE: Executing Tasks
NOTE: Tasks Summary: Attempted 1 tasks of which 0 didn't need to be rerun and all succeeded.
NOTE: Writing buildhistory
NOTE: Writing buildhistory took: 0 seconds
NOTE: Started PRServer with DBfile: /workdir/build/phyboard-polis-imx8mm-wic/cache/prserv.sqlite3, IP: 127.0.0.1, PORT: 34744, PID: 23357
Loading cache: 100% |#########################################################################################################################################| Time: 0:00:00
Loaded 3385 entries from dependency cache.
Parsing recipes: 100% |#######################################################################################################################################| Time: 0:00:00
Parsing of 2275 .bb files complete (2274 cached, 1 parsed). 3386 targets, 210 skipped, 2 masked, 0 errors.
NOTE: Resolving any missing task queue dependencies

Build Configuration:
BB_VERSION           = "1.46.0"
BUILD_SYS            = "x86_64-linux" 
NATIVELSBSTRING      = "universal"
TARGET_SYS           = "aarch64-resy-linux"
MACHINE              = "phyboard-polis-imx8mm"
DISTRO               = "resy"
DISTRO_VERSION       = "3.1.2"
TUNE_FEATURES        = "aarch64 armv8a crc crypto"
TARGET_FPU           = ""
meta
meta-poky
meta-yocto-bsp       = "2020-08-28-dunfell-3.1.2+:d3d80fa6fbf15189f6183a33c95fa90053535ae2"
meta-resy            = "dunfell:2968f06c1e400131e15bd726808a43195eec8c16"
meta-freescale       = "2020-08-28-dunfell:3fc701d11b4b096ba016110c83fe1b48c5f3a256"
meta-phyboard-polis-imx8mm-bsp = "v5.8.x-upstream:e1aaa104ab7879cd1b8f9272aafd06c24691ccb5"
meta-oe
meta-python
meta-networking      = "2020-04-30-dunfell-3.1:17fd382f3467e20308924499b7531ae8b789f056"

Initialising tasks: 100% |####################################################################################################################################| Time: 0:00:00
Sstate summary: Wanted 3 Found 3 Missed 0 Current 100 (100% match, 100% complete)
NOTE: Executing Tasks
NOTE: Tasks Summary: Attempted 459 tasks of which 453 didn't need to be rerun and all succeeded.
NOTE: Writing buildhistory
NOTE: Writing buildhistory took: 0 seconds
pokyuser@862ca11939a7:/workdir/build$ cat /workdir/build/phyboard-polis-imx8mm-wic/tmp/work/aarch64-mx8mm-resy-linux/firmware-imx-8m/8.5-r0/temp/log.task_order
do_deploy_setscene (23394): log.do_deploy_setscene.23394
do_deploy_source_date_epoch_setscene (23411): log.do_deploy_source_date_epoch_setscene.23411
pokyuser@862ca11939a7:/workdir/build$

Now we explicitly told our u-boot recipe that u-boot/do_compile depends on firmware-imx-8m/do_deploy and this does now what we want. 

The log files show that do_deploy_setscene and do_deploy_source_date_epoch_setscene were executed, meaning the build artifacts of firmware-imx-8m ended up where u-boot-phytec-imx can pick them up.

Conclusion

  1. Read the BitBake Manual - when done
  2. Read the Mega Manual - when done
  3. Ask and contribute to our community
  4. Continue with step 1

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Introduction This work is sponsored by Reliable Embedded Systems . You can find more information about our training/consulting services here . Objectives The goal of this blog post is to point out a well known and documented issue with kernel modules not ending up on the root file system which is likely overseen by people until they stumble over it.   Kernel module(s) So you created a brand new kernel module, or you just wanted to include all the kernel modules in the root file system, or just one of them. You reach out to the community mailing list or chat with something like this: I have MACHINE_EXTRA_RRECOMMENDS + = "kernel-modules" in my machine configuration. When I look into the rootfs I see no modules installed in /lib/modules/ $( uname -r ) . I get only a modules tarball in the deploy directory. I also tried MACHINE_EXTRA_RDEPENDS + = "kernel-modules" and it still does not work. What am I doing wrong? Check the Mega Manual If things d
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Yocto/Qt5: hello-qt part2 - Licensing

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Introduction This work is sponsored by Reliable Embedded Systems . You can find more information about our training/consulting services here . Objectives The goal of this blog post is to show my journey trying to build a hello-qt application and reasons why I don't like Qt . As far as I can tell this is going to be a multi part blog post. You might want to have a look at part one as well. Disclaimer: I am not a lawyer, so I can not give legal advice. GPL and LGPL licenses LGPL v2.x Typically libraries are licensed with this license You need to provide the source code (including modifications) and instructions on how to build the LGPL v2.1 licensed code In case your application links statically against LGPL licensed code you need to provide the object files of your applications to be able to replace the LGPL'ed code with different versions In case your application links dynamically against LGPL licensed code you can replace the LGPL'ed libraries without the objec
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