Yocto BB File Analysis

BB File
- SRC_URI : Storage location containing source files (where to import source files), patch files to be applied to source file
${GLIBC_GIT_URI} : git address

Branch: Branch to check out

.patch :(automatically, Yocto applies patch files on build)

- do_fetch : location to read

- do_configure : what to set at build  (You can create config files by writing new content.)

- do_comile : Compile command (insert command to perform when compile)

- do_install : Location to install (insert command to place the results generated after Compile is completed)

- Require keyword : Keyword used to include script contents of other files (keyword "include" in C language)

- .bbappend : To add a bb file. (Usually used to add compile options or patch files on the other board)

Yocto Example of an existing file : poky/meta/recipes-core/glibc/glibc_2.31.bb

require glibc.inc

require glibc-version.inc

DEPENDS += "gperf-native bison-native make-native"

NATIVESDKFIXES ?= ""

NATIVESDKFIXES_class-nativesdk = "\

           file://0003-nativesdk-glibc-Look-for-host-system-ld.so.cache-as-.patch \

           file://0004-nativesdk-glibc-Fix-buffer-overrun-with-a-relocated-.patch \

           file://0005-nativesdk-glibc-Raise-the-size-of-arrays-containing-.patch \

           file://0006-nativesdk-glibc-Allow-64-bit-atomics-for-x86.patch \

           file://0007-nativesdk-glibc-Make-relocatable-install-for-locales.patch \

"

SRC_URI =  "${GLIBC_GIT_URI};branch=${SRCBRANCH};name=glibc \

           file://etc/ld.so.conf \

           file://generate-supported.mk \

           file://makedbs.sh \

           \

           ${NATIVESDKFIXES} \

           file://0008-fsl-e500-e5500-e6500-603e-fsqrt-implementation.patch \

           file://0009-readlib-Add-OECORE_KNOWN_INTERPRETER_NAMES-to-known-.patch \

           file://0010-ppc-sqrt-Fix-undefined-reference-to-__sqrt_finite.patch \

           file://0011-__ieee754_sqrt-f-are-now-inline-functions-and-call-o.patch \

           file://0012-Quote-from-bug-1443-which-explains-what-the-patch-do.patch \

           file://0013-eglibc-run-libm-err-tab.pl-with-specific-dirs-in-S.patch \

           file://0014-__ieee754_sqrt-f-are-now-inline-functions-and-call-o.patch \

           file://0015-sysdeps-gnu-configure.ac-handle-correctly-libc_cv_ro.patch \

           file://0016-Add-unused-attribute.patch \

           file://0017-yes-within-the-path-sets-wrong-config-variables.patch \

           file://0018-timezone-re-written-tzselect-as-posix-sh.patch \

           file://0019-Remove-bash-dependency-for-nscd-init-script.patch \

           file://0020-eglibc-Cross-building-and-testing-instructions.patch \

           file://0021-eglibc-Help-bootstrap-cross-toolchain.patch \

           file://0022-eglibc-Resolve-__fpscr_values-on-SH4.patch \

           file://0023-eglibc-Forward-port-cross-locale-generation-support.patch \

           file://0024-Define-DUMMY_LOCALE_T-if-not-defined.patch \

           file://0025-localedef-add-to-archive-uses-a-hard-coded-locale-pa.patch \

           file://0026-elf-dl-deps.c-Make-_dl_build_local_scope-breadth-fir.patch \

           file://0027-intl-Emit-no-lines-in-bison-generated-files.patch \

           file://0028-inject-file-assembly-directives.patch \

           file://0029-locale-prevent-maybe-uninitialized-errors-with-Os-BZ.patch \

           file://CVE-2020-10029.patch \

           file://0030-Improve-IFUNC-check-BZ-25506.patch \

           file://0031-Fix-build-with-GCC-10-when-long-double-double.patch \

           "

S = "${WORKDIR}/git"

B = "${WORKDIR}/build-${TARGET_SYS}"

PACKAGES_DYNAMIC = ""

# the -isystem in bitbake.conf screws up glibc do_stage

BUILD_CPPFLAGS = "-I${STAGING_INCDIR_NATIVE}"

TARGET_CPPFLAGS = "-I${STAGING_DIR_TARGET}${includedir}"

GLIBC_BROKEN_LOCALES = ""

GLIBCPIE ??= ""

EXTRA_OECONF = "--enable-kernel=${OLDEST_KERNEL} \

                --disable-profile \

                --disable-debug --without-gd \

                --enable-clocale=gnu \

                --with-headers=${STAGING_INCDIR} \

                --without-selinux \

                --enable-tunables \

                --enable-bind-now \

                --enable-stack-protector=strong \

                --enable-stackguard-randomization \

                --disable-crypt \

                --with-default-link \

                --enable-nscd \

                ${@bb.utils.contains_any('SELECTED_OPTIMIZATION', '-O0 -Og', '--disable-werror', '', d)} \

                ${GLIBCPIE} \

                ${GLIBC_EXTRA_OECONF}"

EXTRA_OECONF += "${@get_libc_fpu_setting(bb, d)}"

do_patch_append() {

    bb.build.exec_func('do_fix_readlib_c', d)

}

do_fix_readlib_c () {

sed -i -e 's#OECORE_KNOWN_INTERPRETER_NAMES#${EGLIBC_KNOWN_INTERPRETER_NAMES}#' ${S}/elf/readlib.c

}

do_configure () {

# override this function to avoid the autoconf/automake/aclocal/autoheader

# calls for now

# don't pass CPPFLAGS into configure, since it upsets the kernel-headers

# version check and doesn't really help with anything

        (cd ${S} && gnu-configize) || die "failure in running gnu-configize"

        find ${S} -name "configure" | xargs touch

        CPPFLAGS="" oe_runconf

}

LDFLAGS += "-fuse-ld=bfd"

do_compile () {

base_do_compile

echo "Adjust ldd script"

if [ -n "${RTLDLIST}" ]

then

prevrtld=`cat ${B}/elf/ldd | grep "^RTLDLIST=" | sed 's#^RTLDLIST="\?\([^"]*\)"\?$#\1#'`

# remove duplicate entries

newrtld=`echo $(printf '%s\n' ${prevrtld} ${RTLDLIST} | LC_ALL=C sort -u)`

echo "ldd \"${prevrtld} ${RTLDLIST}\" -> \"${newrtld}\""

sed -i ${B}/elf/ldd -e "s#^RTLDLIST=.*\$#RTLDLIST=\"${newrtld}\"#"

fi

}

require glibc-package.inc

BBCLASSEXTEND = "nativesdk"

#Yocto #Bitbake #BB #Command #Example