Cross debugging ARM

cross_debug.txt

pacman -S qemu-arch-extra
yay -S gdb-multiarch

get ARM libs from http://mirror.archlinuxarm.org/armv7h/core/ and extract usr/ :
tar -xvpf glibc-2.30-3-armv7h.pkg.tar.xz usr

$ qemu-arm -L usr -g 12345 ./a.out &
$ gdb-multiarch ./a.out
(gdb) set arch arm
The target architecture is assumed to be mips
(gdb) set endian little
The target is assumed to be little endian
(gdb) set solib-absolute-prefix ./usr
(gdb) target remote localhost:12345


Also we can put library in QEMU_LD_PREFIX default path (see qemu-arm --help)
mkdir /usr/gnemul
ln -s /home/olivier/libs_foreign/arm/usr qemu-arm

We don't need any more to specify (-L) library path