buildrootschalter/package/uclibc
Alexey Brodkin cde947f5f5 uclibc: prevent rebuilding after installation to staging
Currently we configure uClibc to use kernel headers from "staging" folder with
KERNEL_HEADERS="$(STAGING_DIR)/usr/include". This path is added to include
search path of uClibc build system in Rules.mak "CFLAGS += -I$(KERNEL_HEADERS)".

At the same time on uClibc installation to "staging" we point to the same
location "$(STAGING_DIR)/usr" (headers effectively go in "usr/include").

So after every installation to "staging" dependences get touched (even though we
copy the same headers every time) and so we may see lots of sources in uClibc
get rebuilt.

This has 2 consequences:
1. Longer build time - becase even on ordinary buildroot build uClibc is built
twice. On "uclibc building" and on "uclibc installation to target".

2. Symbols in libuClibc built initially (that is later installed in
"staging/sysroot") are situated with different offset compared to second build
(later copied in "target"). This happens because as described above only part
of sources get rebuilt and then on final linkage object files are linked in
different order.

And (2) leads to problems on remote rebugging: gdbserver reports offsets that
correspond to pointless assembly in libuClibc on host.

Here's how it looks like.

Before this patch:
$ cd ~/br2_output/i586/target/lib
$ i586-buildroot-linux-uclibc-readelf -s libuClibc-0.9.33.2.so | grep kill
   423: 0000c42c    54 FUNC    GLOBAL DEFAULT    7 kill

$ cd ~/br2_output/i586/staging/lib
$ i586-buildroot-linux-uclibc-readelf -s libuClibc-0.9.33.2.so | grep kill
   423: 0000b518    54 FUNC    GLOBAL DEFAULT    7 kill

After this patch:
$ cd ~/br2_output/i586/target/lib
$ i586-buildroot-linux-uclibc-readelf -s libuClibc-0.9.33.2.so | grep kill
   423: 0000b518    54 FUNC    GLOBAL DEFAULT    7 kill

$ cd ~/br2_output/i586/staging/lib
$ i586-buildroot-linux-uclibc-readelf -s libuClibc-0.9.33.2.so | grep kill
   423: 0000b518    54 FUNC    GLOBAL DEFAULT    7 kill

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>

Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Peter Korsgaard <peter@korsgaard.com>
Cc: Noam Camus <noamc@ezchip.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
2014-06-17 20:40:23 +02:00
..
0.9.31.1
0.9.32.1
0.9.33.2 uclibc: add patches to fix MIPS __SIGRTMAX and SIG127 2014-06-09 11:27:04 +02:00
7bf35c8b7d4a1f97174eb49f47f33946b282114c uclibc: fix build without LARGEFILE for xtensa 2014-06-03 09:17:29 +02:00
Config.in arch/arm: drop ARM(7TDMI/720T/740T) support 2014-05-08 16:53:49 +02:00
uClibc-0.9.31.config
uClibc-0.9.32.config
uClibc-0.9.33.config
uClibc-snapshot.config
uclibc.mk uclibc: prevent rebuilding after installation to staging 2014-06-17 20:40:23 +02:00