| 1 |
Hi, |
| 2 |
|
| 3 |
== Progress of last Week == |
| 4 |
|
| 5 |
In the last week, I made armv7a-hardfloat-linux-gnueabi-gcc [ELF |
| 6 |
32-bit LSB executable, Intel 80386, version 1 (SYSV), dynamically |
| 7 |
linked (uses shared libs), for GNU/Linux 2.6.9, stripped] run in the |
| 8 |
arm chroot. |
| 9 |
|
| 10 |
Firstly, I think it is very difficult to switch dynamic libraries |
| 11 |
using ld.so.conf and ldconfig, because the generated ld.so.cache |
| 12 |
always includes /lib. |
| 13 |
My investigation shows: |
| 14 |
|
| 15 |
glibc-2.14.1/Makeconfig: |
| 16 |
# Where to install the shared library and dynamic linker. |
| 17 |
ifndef slibdir |
| 18 |
slibdir = $(exec_prefix)/lib |
| 19 |
endif |
| 20 |
|
| 21 |
glibc-2.14.1/elf/Makefile: |
| 22 |
CFLAGS-ldconfig.c = $(SYSCONF-FLAGS) -D'LIBDIR="$(libdir)"' \ |
| 23 |
-D'SLIBDIR="$(slibdir)"' -DIS_IN_ldconfig=1 |
| 24 |
|
| 25 |
glibc-2.14.1/elf/ldconfig.c: |
| 26 |
if (!opt_only_cline) |
| 27 |
{ |
| 28 |
parse_conf (config_file, true); |
| 29 |
|
| 30 |
/* Always add the standard search paths. */ |
| 31 |
add_system_dir (SLIBDIR); |
| 32 |
if (strcmp (SLIBDIR, LIBDIR)) |
| 33 |
add_system_dir (LIBDIR); |
| 34 |
} |
| 35 |
|
| 36 |
Therefore, ldconfig will always include /lib library path unless using |
| 37 |
"ldconfig -n xxx". But "ldconfig -n" won't generate new ld.so.cache. |
| 38 |
|
| 39 |
Actually, the linker seeks libraries following the sequence: |
| 40 |
a. DT_RPATH in dynamic section. |
| 41 |
b. LD_LIBRARY_PATH environment variable. |
| 42 |
c. ld.so.cache |
| 43 |
|
| 44 |
Instead, I was using LD_LIBRARY_PATH rather than ld.so.conf. The steps are: |
| 45 |
|
| 46 |
1. mount native libs to chroot |
| 47 |
mount --bind /lib gentoo-rootfs/native/lib |
| 48 |
mount --bind /usr/lib gentoo-rootfs/native/usr/lib |
| 49 |
mount --bind /usr/local/lib gentoo-rootfs/native/usr/local/lib |
| 50 |
mount --bind /usr/i686-pc-linux-gnu gentoo-rootfs/native/usr/i686-pc-linux-gnu |
| 51 |
|
| 52 |
2. start arm chroot and link native libs |
| 53 |
./lxc.sh start -n gentoo-arm |
| 54 |
export LD_LIBRARY_PATH="/native/lib:/native/usr/lib:/native/usr/local/lib" |
| 55 |
|
| 56 |
3. set up dynamic library interpreter |
| 57 |
ln -s /native/lib/ld-2.14.1.so /lib/ld-linux.so.2 |
| 58 |
|
| 59 |
4. running native armv7a-hardfloat-linux-gnueabi-gcc |
| 60 |
./native/usr/i686-pc-linux-gnu/armv7a-hardfloat-linux-gnueabi/gcc-bin/4.5.3/armv7a-hardfloat-linux-gnueabi-gcc |
| 61 |
build an arm program using armv7a-hardfloat-linux-gnueabi-gcc successfully |
| 62 |
|
| 63 |
== Plans for this week == |
| 64 |
|
| 65 |
1. Integrate my progress into lxc.sh script |
| 66 |
2. get some valuations comparing native gcc and emulated gcc |
| 67 |
3. document all the steps in the wiki |
Archives