/lib/libgcc_s.so.1: version `GCC_3.5'

root@zedboard-zynq7:~# /usr/xenomai/demo/altency 
/usr/xenomai/demo/altency: /lib/libgcc_s.so.1: version `GCC_3.5' not found (required by /usr/xenomai/demo/altency)
/usr/xenomai/demo/altency: /lib/libgcc_s.so.1: version `GCC_3.5' not found (required by /usr/xenomai/lib/libalchemy.so.0)
/usr/xenomai/demo/altency: /lib/libgcc_s.so.1: version `GCC_3.5' not found (required by /usr/xenomai/lib/libcopperplate.so.0)
/usr/xenomai/demo/altency: /lib/libgcc_s.so.1: version `GCC_3.5' not found (required by /usr/xenomai/lib/libcobalt.so.2)
/usr/xenomai/demo/altency: /lib/libgcc_s.so.1: version `GCC_3.5' not found (required by /usr/xenomai/lib/libmodechk.so.0)

 从交叉编译工具链拷贝 scp /usr/arm-linux-gnueabihf/lib/libgcc_s.so.1 root@10.11.11.83:~

root@zedboard-zynq7:~# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 0e:b0:ba:5e:ba:12 brd ff:ff:ff:ff:ff:ff
    inet 10.11.11.83/24 scope global eth0
       valid_lft forever preferred_lft forever
3: tunl0@NONE: <NOARP> mtu 1480 qdisc noop state DOWN group default qlen 1
    link/ipip 0.0.0.0 brd 0.0.0.0
root@zedboard-zynq7:~# ls
libgcc_s.so.1
root@zedboard-zynq7:~# 

root@zedboard-zynq7:~# cp libgcc_s.so.1 /lib/ 
root@zedboard-zynq7:~# /usr/xenomai/demo/altency 
   0"000.000| BUG in __xenomai_init(): [main] running non-SMP libraries on SMP kernel?
              build with --enable-smp or disable check with --no-sanity

libgcc是什么

这是gcc官方的解释，https://gcc.gnu.org/onlinedocs/gccint/Libgcc.html ，这里有个中文版http://gccint.cding.org/Libgcc.html，最明显的看到了整型和浮点数的转换，而产品平台正好是软浮点。

libgcc的静态库是libgcc.a，动态库是libgcc_s.so.1(libgcc_s.so指向libgcc_s.so.1)。

libgcc是GCC提供的一个低层运行时库，当一些操作/运算在特定平台上不支持时，GCC会自动生成对这些库函数的调用，使用这些库函数来模拟实现。从概念上和源码实现中，又可以分为libgcc1和libgcc2，虽然它们最终会被编译合并为libgcc.a。

From《libgcc1和libgcc2的区别》

是否需要libgcc_s.so.1

搜索到下面一个信息 https://wiki.osdev.org/Libgcc

When do I need to link with libgcc?

All code compiled with GCC must be linked with libgcc.

[root@centos7 glibc]# rpm -qlp libgcc-12.0.1-0.14.fc36.armv7hl.rpm 
warning: libgcc-12.0.1-0.14.fc36.armv7hl.rpm: Header V4 RSA/SHA256 Signature, key ID 38ab71f4: NOKEY
/lib/libgcc_s-12-20220401.so.1
/lib/libgcc_s.so.1
/usr/lib/.build-id
/usr/lib/.build-id/b7
/usr/lib/.build-id/b7/db0eb9e1ff45a0d769b266513dc956eaf1c0d9
/usr/share/licenses/libgcc
/usr/share/licenses/libgcc/COPYING
/usr/share/licenses/libgcc/COPYING.LIB
/usr/share/licenses/libgcc/COPYING.RUNTIME
/usr/share/licenses/libgcc/COPYING3
/usr/share/licenses/libgcc/COPYING3.LIB
[root@centos7 glibc]#