On 3/22/16 7:21 AM, Bruce Ashfield wrote:
>
>
> On Tue, Mar 22, 2016 at 8:12 AM, Hongxu Jia <hongxu.jia@windriver.com
> <mailto:hongxu.jia@windriver.com>> wrote:
>
> Since CFLAGS CPPFLAGS CXXFLAGS has been unset, variable DEBUG_FLAGS could
> not been passed to compiler, so we explicitly add DEBUG_FLAGS to CC to
> replace build path with target path.
>
>
> Can you be more explicit here ? What is typically contained in DEBUG_FLAGS ? The
> kernel builds its own compiler line and flags, so anything you are setting from this
> environment, should not be leaking into the kernel build.
>
> .. which leaves me wondering, what exactly is in DEBUG_FLAGS, and how is it
> actually fixing the QA issue ?
The specific debug flag in question is being added to remap the on-disk path to
the path we want the items to look like from a debugging point of view.
The typical format of DEBUG_FLAGS is something like:
DEBUG_FLAGS ?= "-g -feliminate-unused-debug-types"
This was recently updated to include the remapping:
DEBUG_FLAGS ?= "-g -feliminate-unused-debug-types \
-fdebug-prefix-map=${WORKDIR}=/usr/src/debug \
-fdebug-prefix-map=${STAGING_DIR_NATIVE}= \
-fdebug-prefix-map=${STAGING_DIR_HOST}= \
The idea is the WORKDIR is replaced with '/usr/src/debug' inside of the binary
and any debug symbol references. This makes it much easier for the system to
work with supplied debug sources/symbols.
I'm not sure you want to use DEBUG_FLAGS since anything can be put in there....
Application space code should always use the DEBUG_FLAGS, or I think it's likely
a bug.
The kernel though should probably define it's own flag(s). Most likely you'll
want something simple like:
-fdebug-prefix-map=${WORKDIR}=/usr/src/debug
Then all of the internal references to WORKDIR will be replaced with
'/usr/src/debug' which cross gdb can 'map' or on-target will actually look in
that location. (A corresponding '-dbg' package should be provided with the
matching compilation sources at the local specified.)
--Mark
> Bruce
>
>
>
> [YOCTO #7058]
>
> Signed-off-by: Hongxu Jia <hongxu.jia@windriver.com
> <mailto:hongxu.jia@windriver.com>>
> <mailto:Openembedded-core@lists.openembedded.org>> ---
> meta/classes/kernel.bbclass | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/meta/classes/kernel.bbclass b/meta/classes/kernel.bbclass
> index c3eab50..d357ccf 100644
> --- a/meta/classes/kernel.bbclass
> +++ b/meta/classes/kernel.bbclass
> @@ -207,7 +207,7 @@ kernel_do_compile() {
> copy_initramfs
>
> use_alternate_initrd=CONFIG_INITRAMFS_SOURCE=${B}/usr/${INITRAMFS_IMAGE}-${MACHINE}.cpio
> fi
> - oe_runmake ${KERNEL_IMAGETYPE_FOR_MAKE} ${KERNEL_ALT_IMAGETYPE}
> CC="${KERNEL_CC}" LD="${KERNEL_LD}" ${KERNEL_EXTRA_ARGS} $use_alternate_initrd
> + oe_runmake ${KERNEL_IMAGETYPE_FOR_MAKE} ${KERNEL_ALT_IMAGETYPE}
> CC="${KERNEL_CC} ${DEBUG_FLAGS}" LD="${KERNEL_LD}" ${KERNEL_EXTRA_ARGS}
> $use_alternate_initrd
> if test "${KERNEL_IMAGETYPE_FOR_MAKE}.gz" = "${KERNEL_IMAGETYPE}"; then
> gzip -9c < "${KERNEL_IMAGETYPE_FOR_MAKE}" > "${KERNEL_OUTPUT}"
> fi
> @@ -216,7 +216,7 @@ kernel_do_compile() {
> do_compile_kernelmodules() {
> unset CFLAGS CPPFLAGS CXXFLAGS LDFLAGS MACHINE
> if (grep -q -i -e '^CONFIG_MODULES=y$' ${B}/.config); then
> - oe_runmake -C ${B} ${PARALLEL_MAKE} modules
> CC="${KERNEL_CC}" LD="${KERNEL_LD}" ${KERNEL_EXTRA_ARGS}
> + oe_runmake -C ${B} ${PARALLEL_MAKE} modules CC="${KERNEL_CC}
> ${DEBUG_FLAGS}" LD="${KERNEL_LD}" ${KERNEL_EXTRA_ARGS}
>
> # Module.symvers gets updated during the
> # building of the kernel modules. We need to
> --
> 1.9.1
>
> --
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>
>
>
> --
> "Thou shalt not follow the NULL pointer, for chaos and madness await thee at its
> end"