Re: [PATCH 01/17] conf/bitbake.conf package.bbclass: fix dbg package not contain sources while -fdebug-prefix-map used

[Mark Hatle <mark.hatle@windriver.com>]

On 4/19/16 2:33 AM, Hongxu Jia wrote:
> Hi all,
> 
> With some investigation, there is an example to explain how to do remote debug.
> 
> Also file [YOCTO #9481] for document.
> 
> Hi Andreas,
> 
> Would you please have a look the example, to see if it could fit your case.
> 
> Example:
> 
> 1. Build a image with gdbserver and gzip installed. The gzip
>    is the debug binary. Append the following to local.conf
> ...
> IMAGE_INSTALL_append = " gdbserver gzip"
> ...
> 
> $ bitbake core-image-sato
> 
> 2. Build gdb-cross for remote debug on host
> 
> $ bitbake gdb-cross-i586
> 
> 3. start qemu
> 
> $ runqemu qemux86 core-image-sato
> 
> 4. On host side, create symlink /usr/src/debug to
>    ${BASE_WORKDIR}/${MULTIMACH_TARGET_SYS} which the
>    location of sources is /usr/src/debug.
> 
> $ ln -snf /TOPDIR/tmp/work/i586-poky-linux /usr/src/debug

This is incorrect.  On the host you use the combination of:

(gdb) set sysroot <your debug capable fs path>
(gdb) set substitute-path /usr/src/debug <your debug capable fs path>/usr/src/debug

> 5. On target side, ipaddr is 128.224.163.187,
>    run gdbserver to debug "gzip -h"
> 
> root@qemux86-64:~# gdbserver localhost:1024 gzip -h
> Process gzip created; pid = 530
> Listening on port 1024
> 
> 6. On host side, enter gzip's devshell
> $ bitbake -cdevshell gzip
> 
> 7. On host side, run gdb-cross to remote debug gzip
> 
> gzip-1.6# i586-poky-linux-gdb ../build/gzip
> 
> 8. Use path ${STAGING_DIR_HOST} as the system root for
>    the program being debugged. Any absolute shared
>    library paths will be prefixed with path;
> 
> (gdb) set sysroot /TOPDIR/tmp/sysroots/qemux86
> 
> 
> 9. Start remote target, set break point at help()
> 
> (gdb) target remote 128.224.163.187:1024
> (gdb) break gzip.c:325
> (gdb) info break
> Num     Type           Disp Enb Address            What
> 1       breakpoint     keep y   0x0000000000401ec1 in main at
> /usr/src/debug/gzip/1.6-r0/gzip-1.6/gzip.c:325
> (gdb) c
> Continuing.
> 
> Breakpoint 1, main (argc=2, argv=0x7fffffffeca8) at
> /usr/src/debug/gzip/1.6-r0/gzip-1.6/gzip.c:465
> 465                 help(); do_exit(OK); break;
> (gdb) list
> 460             case 'd':
> 461                 decompress = 1; break;
> 462             case 'f':
> 463                 force++; break;
> 464             case 'h': case 'H':
> 465                 help(); do_exit(OK); break;
> 466             case 'k':
> 467                 keep = 1; break;
> 468             case 'l':
> 469                 list = decompress = to_stdout = 1; break;
> (gdb) c
> Continuing.
> [Inferior 1 (process 1246) exited normally]
> 
> 
> 10. On target side, get output of "gzip -h"
> [snip]
> Remote debugging from host 128.224.153.74
> Usage: gzip [OPTION]... [FILE]...
> Compress or uncompress FILEs (by default, compress FILES in-place).
> 
> Mandatory arguments to long options are mandatory for short options too.
> 
>   -c, --stdout      write on standard output, keep original files unchanged
>   -d, --decompress  decompress
>   -f, --force       force overwrite of output file and compress links
>   -h, --help        give this help
>   -k, --keep        keep (don't delete) input files
>   -l, --list        list compressed file contents
>   -L, --license     display software license
>   -n, --no-name     do not save or restore the original name and time stamp
>   -N, --name        save or restore the original name and time stamp
>   -q, --quiet       suppress all warnings
>   -r, --recursive   operate recursively on directories
>   -S, --suffix=SUF  use suffix SUF on compressed files
>   -t, --test        test compressed file integrity
>   -v, --verbose     verbose mode
>   -V, --version     display version number
>   -1, --fast        compress faster
>   -9, --best        compress better
> 
> With no FILE, or when FILE is -, read standard input.
> 
> Report bugs to <bug-gzip@gnu.org>.
> 
> Child exited with status 0
> GDBserver exiting
> [snip]
> 
> //Hongxu
>