$ cd <yocto-proj-dir>
$ sources/core/scripts/contrib/convert-overrides.py <meta-layer-path>

$ petalinux-build -c bbexample
$ petalinux-build -c bbexample-rt
$ petalinux-build -c bbexample-lt

cd <plnx-proj-root>
petalinux-config --> Yocto Settings --> User Layers --> (/absolute_path_to_meta_layer/meta-example) user layer 0 
													--> ()    user layer 1

BBLAYERS := " \
  ${SDKBASEMETAPATH}/layers/poky/meta \
  ${SDKBASEMETAPATH}/layers/poky/meta-poky \
  /absolute_path_to_meta_layer/meta-example \
  "

# Use local tarball
SRC_URI = "file://bbexample-${PV}.tar.gz"

$ petalinux-build -c bbexample-lt

$ petalinux-build -c bbexample-lt
 
[INFO] building bbexample-lt
[INFO] sourcing bitbake
INFO: bitbake bbexample-lt
Loading cache: 100% |###############################################################################################################################################################################| ETA:  00:00:00
Loaded 2941 entries from dependency cache.
Parsing recipes: 100% |#############################################################################################################################################################################| Time: 00:00:01
Parsing of 2328 .bb files complete (2294 cached, 34 parsed). 2943 targets, 196 skipped, 0 masked, 0 errors.
NOTE: Resolving any missing task queue dependencies
NOTE: Preparing RunQueue
NOTE: Checking sstate mirror object availability (for 38 objects)
NOTE: Executing SetScene Tasks
NOTE: Executing RunQueue Tasks
NOTE: Tasks Summary: Attempted 872 tasks of which 857 didn't need to be rerun and all succeeded.
INFO: Copying Images from deploy to images
[INFO] successfully built bbexample-lt

$ vim <plnx-proj-root>/project-spec/meta-user/recipes-bsp/fsbl/fsbl_%.bbappend
# From 2021.1 onwards
$ vim <plnx-proj-root>/project-spec/meta-user/recipes-bsp/embeddedsw/fsbl-firmware_%.bbappend

#Add debug for FSBL
XSCTH_BUILD_DEBUG = "1"

#Add compiler flags for FSBL
#For v2022.1 or later PetaLinux releases
YAML_COMPILER_FLAGS:append = " -DFSBL_PROT_BYPASS"

#For v2021.2 and old PetaLinux releases
YAML_COMPILER_FLAGS_append = " -DENABLEDFSBL_PROT_EM"
 
# Note: This is not required if you are using Yocto
# CAUTION!: EXTERNALXSCTSRC and EXTERNALXSCTSRC_BUILD is required only for 2018.2 and below petalinux releases
EXTERNALXSCTSRC = ""
EXTERNALXSCTSRC_BUILD = ""

#Add BSP flags for FSBL
YAML_BSP_CONFIG += "secure_mode"
YAML_BSP_CONFIG[secure_mode] = "set,true"

#For v2018.1 or later PetaLinux release "petalinux-build -x mrproper" command will remove releases only
$ vim <plnx-proj-root>/components/plnx_workspace directory
$ rm -rf /project-spec/meta-user/recipes-bsp/pmu-firmware/pmu-firmware_%.bbappend

# From 2021.1 onwards
$ vim <plnx-proj-root>/components/plnx_workspace

Note that the method of loading the PMUFW can prevent early prints (during code initialization) from being output.  See PMU Firmware > Using FSBL to load PMUFW for additional details.

$ petalinux-build -c pmufw

$ petalinux-build -c plm

# For 2018.2 and below versions
do_compile_prepend(){
   install -m 0644 ${TOPDIR}/../project-spec/hw-description/psu_init.c ${TOPDIR}/../components/plnx_workspace/fsbl/fsbl_hwproj/psu_init.c
}

# For 2018.3 and later versions we removed FSBL and PMUFW external workspace from <plnx-proj-root>/components/plnx_workspace directory
# to align Yocto patching mechanism. Hence we are copying the files to build workspace(${B})
# https://github.com/Xilinx/meta-xilinx-tools/blob/rel-v2018.3/classes/xsctbase.bbclass#L14
do_compile_prepend(){
   install -m 0644 ${TOPDIR}/../project-spec/hw-description/psu_init.c ${B}/fsbl/psu_init.c
}

## From 2021.1 onwards

do_compile_prepend(){
   install -m 0644 ${TOPDIR}/../project-spec/hw-description/psu_init.c ${B}/fsbl-firmware/psu_init.c
}

# For 2022.1 release onwards
do_compile:prepend(){
   install -m 0644 ${TOPDIR}/../project-spec/hw-description/psu_init.c ${B}/fsbl-firmware/psu_init.c
}

$ petalinux-create -t apps --template install --name libcpsample --enable
$ cp libcpsample.so.1.0.1 <plnx-proj-root>/project-spec/meta-user/recipes-apps/libcpsample/files
$ cp cpsample.h <plnx-proj-root>/project-spec/meta-user/recipes-apps/libcpsample/files

$ petalinux-create -t apps --template install --name libcpsample --enable --srcuri "<path-to-dir>/libcpsample.so.1.0.1 <path-to-dir>/cpsample.h>"

$ mkdir -p <layer-path>/recipes-apps/libcpsample/files
$ touch <layer-path>/recipes-apps/libcpsample/libcpsample.bb
$ cp libcpsample.so.1.0.1 <layer-path>/recipes-apps/libcpsample/files
$ cp cpsample.h <layer-path>/recipes-apps/libcpsample/files

#
# This file is the libcpsample recipe.
#
 
SUMMARY = "Sample pre-built library copy to rootfs"
SECTION = "libs"
LICENSE = "MIT"
LIC_FILES_CHKSUM = "file://${COMMON_LICENSE_DIR}/MIT;md5=0835ade698e0bcf8506ecda2f7b4f302"
 
SRC_URI = " \
    file://libcpsample.so.1.0.1 \
    file://cpsample.h \
"
 
S = "${WORKDIR}"
 
# Add dependency libraries if any
# for example DEPENDS = "libpcap"
 
# If you need to create a symbolic link using the pre-built libraries you should use oe_soinstall.
# This copies libraries to "{TARGET_ROOTFS}/usr/lib" directory and create a symlink as
# lrwxrwxrwx libcpsample.so.1.0 -> libcpsample.so.1.0.1
# -rwxr-xr-x libcpsample.so.1.0.1
 
do_install() {
    install -d ${D}${libdir}
    oe_soinstall ${S}/libcpsample.so.1.0.1 ${D}${libdir}
    install -d -m 0655 ${D}${includedir}/CPSAMPLE
    install -m 0644 ${S}/*.h ${D}${includedir}/CPSAMPLE/
}
 
# Inhibit warnings about files being stripped
INSANE_SKIP:${PN} = "ldflags"
INSANE_SKIP:${PN} = "already-stripped"
 
# If you don't have .h file to copy to /usr/include add something like below
# FILES:${PN} = "${libdir}/*.so.*"
 
FILES:${PN} = "${libdir}/*.so.* ${includedir}/*"
FILES:${PN}-dev = "${libdir}/*.so"

#
# This file is the libcpsample recipe.
#
 
SUMMARY = "Sample pre-built library copy to rootfs"
SECTION = "libs"
LICENSE = "MIT"
LIC_FILES_CHKSUM = "file://${COMMON_LICENSE_DIR}/MIT;md5=0835ade698e0bcf8506ecda2f7b4f302"
 
SRC_URI = " \
    file://libcpsample.so.1.0.1 \
    file://cpsample.h \
"
 
S = "${WORKDIR}"
 
# Add dependency libraries if any
# for example DEPENDS = "libpcap"
 
# If you need to create a symbolic link using the pre-built libraries you should use oe_soinstall.
# This copies libraries to "{TARGET_ROOTFS}/usr/lib" directory and create a symlink as
# lrwxrwxrwx libcpsample.so.1.0 -> libcpsample.so.1.0.1
# -rwxr-xr-x libcpsample.so.1.0.1
 
do_install() {
    install -d ${D}${libdir}
    oe_soinstall ${S}/libcpsample.so.1.0.1 ${D}${libdir}
    install -d -m 0655 ${D}${includedir}/CPSAMPLE
    install -m 0644 ${S}/*.h ${D}${includedir}/CPSAMPLE/
}
 
# Inhibit warnings about files being stripped
INSANE_SKIP_${PN} = "ldflags"
INSANE_SKIP_${PN} = "already-stripped"
 
# If you don't have .h file to copy to /usr/include add something like below
# FILES_${PN} = "${libdir}/*.so.*"
 
FILES_${PN} = "${libdir}/*.so.* ${includedir}/*"
FILES_${PN}-dev = "${libdir}/*.so"

$ petalinux-build -c rootfs

$ petlainux-create -t apps --template c --name libsample --enable

#
# This file is the libsample recipe.
#
 
SUMMARY = "Simple libsample application"
SECTION = "libs"
LICENSE = "MIT"
LIC_FILES_CHKSUM = "file://${COMMON_LICENSE_DIR}/MIT;md5=0835ade698e0bcf8506ecda2f7b4f302"
 
FILESEXTRAPATHS:prepend := "${THISDIR}/files:"
 
SRC_URI = " \
          file://sample.c \
          file://sample.h \
          file://Makefile \
         "
 
S = "${WORKDIR}"
 
PACKAGE_ARCH = "${MACHINE_ARCH}"
PROVIDES = "sample"
TARGET_CC_ARCH += "${LDFLAGS}"
 
do_install() {
    install -d ${D}${libdir}
    install -d ${D}${includedir}
    oe_libinstall -so libsample ${D}${libdir}
    # This is optional and depends if you have any headers to copied along with libraries
    # This example includes sample.h to to copied to <TARGET_ROOTFS>/usr/lib/SAMPLE/sample.h
    install -d -m 0655 ${D}${includedir}/SAMPLE
    install -m 0644 ${S}/*.h ${D}${includedir}/SAMPLE/
}
 
FILES:${PN} = "${libdir}/*.so.* ${includedir}/*"
FILES:${PN}-dev = "${libdir}/*.so"

APP = sample
 
LIBSOURCES=*.c
OUTS = *.o
NAME := sample
MAJOR = 1.0
MINOR = 1
VERSION = $(MAJOR).$(MINOR)
 
all: lib$(NAME).so
lib$(NAME).so.$(VERSION): $(OUTS)
    $(CC) $(LDFLAGS) $(OUTS) -shared -Wl,-soname,lib$(NAME).so.$(MAJOR) -o lib$(NAME).so.$(VERSION)
 
lib$(NAME).so: lib$(NAME).so.$(VERSION)
    rm -f lib$(NAME).so.$(MAJOR) lib$(NAME).so
    ln -s lib$(NAME).so.$(VERSION) lib$(NAME).so.$(MAJOR)
    ln -s lib$(NAME).so.$(MAJOR) lib$(NAME).so
 
%.o: %.c
    $(CC) $(CFLAGS) -c -fPIC $(LIBSOURCES)
 
clean:
    rm -rf *.o *.so *.so.*

$ petalinux-build -c libsample

$ petlainux-create -t apps --template c --name sampleapp --enable

#
# This file is the sampleapp recipe.
#
 
SUMMARY = "Simple sampleapp application"
SECTION = "PETALINUX/apps"
LICENSE = "MIT"
LIC_FILES_CHKSUM = "file://${COMMON_LICENSE_DIR}/MIT;md5=0835ade698e0bcf8506ecda2f7b4f302"
 
FILESEXTRAPATHS:prepend := "${THISDIR}/files:"
 
SRC_URI = " \
          file://sampleapp.c \
         "
 
S = "${WORKDIR}"
 
DEPENDS += " libsample"
 
#This uses libsample.so.1.0.1 (-lsample)
do_compile() {
    ${CC} ${CFLAGS} ${LDFLAGS} -o sampleapp sampleapp.c -lsample
}
 
do_install() {
    install -d ${D}${bindir}
    install -d -m 0755 0655sampleapp ${D}${includedir}/SAMPLE
    install -m 0644 ${S}/*.h ${D}${includedir}/SAMPLE/
}
 
FILES_${PN} = "${libdir}/*.so.* ${includedir}/*"
FILES_${PN}-dev = "${libdir}/*.so"

#
# This file is the sampleapp recipe.
#
 
SUMMARY = "Simple sampleapp application"
SECTION = "PETALINUX/apps"
LICENSE = "MIT"
LIC_FILES_CHKSUM = "file://${COMMON_LICENSE_DIR}/MIT;md5=0835ade698e0bcf8506ecda2f7b4f302"
 
FILESEXTRAPATHS_prepend := "${THISDIR}/files:"
 
SRC_URI = " \
          file://sampleapp.c \
         "
 
S = "${WORKDIR}"
 
DEPENDS += " libsample"
 
#This uses libsample.so.1.0.1 (-lsample)
do_compile() {
    ${CC} ${CFLAGS} ${LDFLAGS} -o sampleapp sampleapp.c -lsample
}
 
do_install() {
    install -d ${D}${bindir}
    install -d -m 0755 sampleapp ${D}${bindir}
}
 
FILES_${PN} += "sampleapp"

#include <stdio.h>
#include <SAMPLE/sample.h>  // From above libs <TARGET_ROOTFS>/usr/lib/SAMPLE/sample.h
 
int main(int argc, char **argv)
{
    printf("Hello World!\n");
    sample_hello();
    return 0;
}

[Unit]
Description=myapp-init
 
[Service]
ExecStart=/usr/bin/myapp-init
StandardOutput=journal+console
 
[Install]
WantedBy=multi-user.target

Below step required only if you are using SYSTEMV as INITMANAGER.