Repository : ssh://git@open-mesh.org/doc

On branches: backup-redmine/2019-10-12,master

commit 83e523ffd1e9eb255568be736c8be01d7b3ec9da Author: Sven Eckelmann sven@narfation.org Date: Sat Oct 12 16:51:34 2019 +0000

doc: open-mesh/OpenWrt_KGDB

83e523ffd1e9eb255568be736c8be01d7b3ec9da open-mesh/OpenWrt_KGDB.textile | 24 +++++++++++++++++++++++- 1 file changed, 23 insertions(+), 1 deletion(-)

diff --git a/open-mesh/OpenWrt_KGDB.textile b/open-mesh/OpenWrt_KGDB.textile index 0b4eb94..d50a4b3 100644 --- a/open-mesh/OpenWrt_KGDB.textile +++ b/open-mesh/OpenWrt_KGDB.textile @@ -187,6 +187,28 @@ lx-symbols .. continue </pre>

+You should make sure that it doesn't load any <code>*.ko</code> files from <code>ipkg-*</code> directories. These files are stripped and doesn't contain the necessary symbol information. When necessary, just delete these folders or specify the folders with the unstripped kernel modules: + +<pre> +lx-symbols lx-symbols ../batman-adv-2019.2/.pkgdir/ ../backports-4.19.66-1/.pkgdir/ ../button-hotplug/.pkgdir/ +</pre> + The rest of the usage now works similar to debugging using gdbserver. Just set some additional breakpoints and let the kernel run again. kgdb will then inform gdb whenever a breakpoints was hit. Just keep in mind that it is not possible to interrupt the kernel from gdb (without a Oops or an already existing breakpoint) - use sysrq from linux for that.

-Some other ideas are documented in [[Emulation_Debug#Using-GDB]]. This document also contains important hints about [[Emulation_Debug#Building-the-batman-adv-module|increasing the chance of getting debugable modules]] which didn't had all information optimized away. \ No newline at end of file +Some other ideas are documented in [[Emulation_Debug#Using-GDB]]. This document also contains important hints about [[Emulation_Debug#Building-the-batman-adv-module|increasing the chance of getting debugable modules]] which didn't had all information optimized away. THe relevant flags could be set directly in the routing feed like this: + +<pre> +diff --git a/batman-adv/Makefile b/batman-adv/Makefile +index a7c6a79..c18f978 100644 +--- a/batman-adv/Makefile ++++ b/batman-adv/Makefile +@@ -89,7 +89,7 @@ define Build/Compile + CROSS_COMPILE="$(TARGET_CROSS)" \ + SUBDIRS="$(PKG_BUILD_DIR)/net/batman-adv" \ + $(PKG_EXTRA_KCONFIG) \ +- EXTRA_CFLAGS="$(PKG_EXTRA_CFLAGS)" \ ++ EXTRA_CFLAGS="$(PKG_EXTRA_CFLAGS) -fno-inline -Og -fno-optimize-sibling-calls" \ + NOSTDINC_FLAGS="$(NOSTDINC_FLAGS)" \ + modules + endef +</pre> \ No newline at end of file