Re: Help figuring out why `info registers` is showing <unavailable> with gdbserver target

[Andrew Burgess <aburgess@redhat.com>]

William Tambe via Gdb-patches <gdb-patches@sourceware.org> writes:

> Regarding this issue, support for gdbserver has been implemented here:
> https://github.com/fontamsoc/binutils-gdb/blob/b2eeeae0/gdbserver/linux-pu32-low.cc
>
> Support for gdb has been implemented here:
> https://github.com/fontamsoc/binutils-gdb/blob/b2eeeae0/gdb/pu32-tdep.c
>
> gdb is able to successfully connect to gdbserver and start a program
> on the target; however, gdb is unable to fetch registers and instead
> shows <unavailable> as follow:
>
> (gdb) info registers
> r0             <unavailable>
> r1             <unavailable>
> r2             <unavailable>
> r3             <unavailable>
> r4             <unavailable>
> r5             <unavailable>
> r6             <unavailable>
> r7             <unavailable>
> r8             <unavailable>
> r9             <unavailable>
> r10            <unavailable>
> r11            <unavailable>
> r12            <unavailable>
> r13            <unavailable>
> r14            <unavailable>
> r15            <unavailable>
> pc             <unavailable>
>
> Find attached full `gdbserver --debug --remote-debug` logs as well as
> gdb logs.

You should consider using 'set debug remote 1' on the GDB side to
capture the remote packets from that perspective.  I'm particularlly
interested in the reply to the 'g' packet, but the complete logs would
be useful.  This information doesn't seem to be visible in the gdbserver
output (or I'm missing it).

Thanks,
Andrew

>
> Any idea what might have been missed while implementing gdbserver support ?
> Would you suggest ways to debug the issue ?
> tambewilliam@kubuntu20200502:~$ sudo /opt/pu32-toolchain/bin/pu32-elf-gdb -x buildroot-build/staging/usr/share/buildroot/gdbinit -ex 'target extended-remote /dev/ttyUSB2' -ex 'set cwd /' && -ex 'monitor set debug 1' -ex 'monitor set remote-debug 1'
> GNU gdb (GDB) 11.0.50.20210718-git
> Copyright (C) 2021 Free Software Foundation, Inc.
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> This GDB was configured as "--host=x86_64-pc-linux-gnu --target=pu32-elf".
> Type "show configuration" for configuration details.
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> warning: File "/home/tambewilliam/.gdbinit" auto-loading has been declined by your `auto-load safe-path' set to "$debugdir:$datadir/auto-load".
> To enable execution of this file add
>         add-auto-load-safe-path /home/tambewilliam/.gdbinit
> line to your configuration file "/root/.config/gdb/gdbinit".
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>         set auto-load safe-path /
> line to your configuration file "/root/.config/gdb/gdbinit".
> For more information about this security protection see the
> "Auto-loading safe path" section in the GDB manual.  E.g., run from the shell:
>         info "(gdb)Auto-loading safe path"
> buildroot-build/staging/usr/share/buildroot/gdbinit: No such file or directory.
> Remote debugging using /dev/ttyUSB2
> (gdb) set remote exec-file /bin/ls
> (gdb) r -l /
> Starting program:  -l /
> Reading /usr/bin/busybox from remote target...
> warning: File transfers from remote targets can be slow. Use "set sysroot" to access files locally instead.
> Reading /usr/bin/busybox from remote target...
> Reading symbols from target:/usr/bin/busybox...
> (No debugging symbols found in target:/usr/bin/busybox)
> warning: Target-supplied registers are not supported by the current architecture
> PC register is not available
> (gdb) info registers
> r0             <unavailable>
> r1             <unavailable>
> r2             <unavailable>
> r3             <unavailable>
> r4             <unavailable>
> r5             <unavailable>
> r6             <unavailable>
> r7             <unavailable>
> r8             <unavailable>
> r9             <unavailable>
> r10            <unavailable>
> r11            <unavailable>
> r12            <unavailable>
> r13            <unavailable>
> r14            <unavailable>
> r15            <unavailable>
> pc             <unavailable>
> (gdb)
> # gdbserver --debug --remote-debug --multi /dev/ttyS1 &
> [2] 94
> root@buildroot:~
> # sigchld_handler
> sigchld_handler
> sigchld_handler
> sigchld_handler
> sigchld_handler
> Remote debugging using /dev/ttyS1
>
> root@buildroot:~
> #
> root@buildroot:~
> #
> root@buildroot:~
> #
> root@buildroot:~
> # handling possible serial event
> [getpkt: discarding char '+']
> getpkt ("qSupported:multiprocess+;swbreak+;hwbreak+;qRelocInsn+;fork-events+;vfork-events+;exec-events+;vContSupported+;QThreadEvents+;no-resumed+;memory-tagging+");  [sending ack]
> [sent ack]
> putpkt ("$PacketSize=47ff;QPassSignals+;QProgramSignals+;QStartupWithShell+;QEnvironmentHexEncoded+;QEnvironmentReset+;QEnvironmentUnset+;QSetWorkingDir+;qXfer:libraries-svr4:read+;augmented-libraries-svr4-read+;qXfer:auxv:read+;qXfer:siginfo:read+;qXfer:siginfo:write+;qXfer:features:read+;qXfer:osdata:read+;multiprocess+;fork-events+;vfork-events+;exec-events+;QNonStop+;QDisableRandomization+;qXfer:threads:read+;ConditionalBreakpoints+;BreakpointCommands+;QAgent+;Qbtrace:bts+;Qbtrace-conf:bts:size+;Qbtrace:pt+;Qbtrace-conf:pt:size+;Qbtrace:off+;qXfer:btrace:read+;qXfer:btrace-conf:read+;swbreak+;hwbreak+;qXfer:exec-file:read+;vContSupported+;QThreadEvents+;no-resumed+#21"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("vMustReplyEmpty");  [sending ack]
> [sent ack]
> putpkt ("$#00"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("!");  [sending ack]
> [sent ack]
> putpkt ("$OK#9a"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("QProgramSignals:0;1;3;4;6;7;8;9;a;b;c;d;e;f;10;11;12;13;14;15;16;17;18;19;1a;1b;1c;1d;1e;1f;20;21;22;23;24;25;26;27;28;29;2a;2b;2c;2d;2e;2f;30;31;32;33;34;35;36;37;38;39;3a;3b;3c;3d;3e;3f;40;41;42;43;44;45;46;47;48;49;4a;4b;4c;4d;4e;4f;50;51;52;53;54;55;56;57;58;59;5a;5b;5c;5d;5e;5f;60;61;62;63;64;65;66;67;68;69;6a;6b;6c;6d;6e;6f;70;71;72;73;74;75;76;77;78;79;7a;7b;7c;7d;7e;7f;80;81;82;83;84;85;86;87;88;89;8a;8b;8c;8d;8e;8f;90;91;92;93;94;95;96;97;");  [sending ack]
> [sent ack]
> putpkt ("$OK#9a"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("Hgp0.0");  [sending ack]
> [sent ack]
> putpkt ("$E01#a6"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("qXfer:features:read:target.xml:0,1000");  [sending ack]
> [sent ack]
> putpkt ("$E01#a6"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("QNonStop:0");  [sending ack]
> [sent ack]
> linux_async (0), previous=0
> [all-stop mode enabled]
> putpkt ("$OK#9a"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("qTStatus");  [sending ack]
> [sent ack]
> putpkt ("$#00"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("?");  [sending ack]
> [sent ack]
>>>>> entering void linux_process_target::stop_all_lwps(int, lwp_info*)
> stop_all_lwps (stop, except=none)
> wait_for_sigstop: pulling events
> LWFE: waitpid(-1, ...) returned -1,
> LLW: exit (no unwaited-for LWP)
> stop_all_lwps done, setting stopping_threads back to !stopping
> <<<< exiting void linux_process_target::stop_all_lwps(int, lwp_info*)
> putpkt ("$W00#b7"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("QDisableRandomization:1");  [sending ack]
> [sent ack]
> [address space randomization disabled]
> putpkt ("$OK#9a"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("QStartupWithShell:1");  [sending ack]
> [sent ack]
> [Inferior will be started with shell]putpkt ("$OK#9a"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("QEnvironmentReset");  [sending ack]
> [sent ack]
> putpkt ("$OK#9a"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("QSetWorkingDir:2f");  [sending ack]
> [sent ack]
> [Set the inferior's current directory to /]
> putpkt ("$OK#9a"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("vRun;2f62696e2f6c73;2d6c;2f");  [sending ack]
> [sent ack]
> args: -l /
>>>>> entering ptid_t linux_process_target::wait_1(ptid_t, target_waitstatus*, target_wait_flags)
> wait_1: [Process 97]
> LWFE: waitpid(-1, ...) returned 0, ERRNO-OK
> leader_pid=97, leader_lp!=NULL=1, num_lwps=1, zombie=0
> sigsuspend'ing
> sigchld_handler
> LWFE: waitpid(-1, ...) returned 97, ERRNO-OK
> LLW: waitpid 97 received SIGTRAP - Trace/breakpoint trap (stopped)
> LWFE: waitpid(-1, ...) returned 0, ERRNO-OK
> Hit a non-gdbserver trap event.
>>>>> entering void linux_process_target::stop_all_lwps(int, lwp_info*)
> stop_all_lwps (stop, except=none)
> wait_for_sigstop: pulling events
> LWFE: waitpid(-1, ...) returned 0, ERRNO-OK
> leader_pid=97, leader_lp!=NULL=1, num_lwps=1, zombie=0
> LLW: exit (no unwaited-for LWP)
> stop_all_lwps done, setting stopping_threads back to !stopping
> <<<< exiting void linux_process_target::stop_all_lwps(int, lwp_info*)
> Checking whether LWP 97 needs to move out of the jump pad...no
> wait_1 ret = LWP 97.97, 1, 5
> <<<< exiting ptid_t linux_process_target::wait_1(ptid_t, target_waitstatus*, target_wait_flags)
>>>>> entering virtual void linux_process_target::resume(thread_resume*, size_t)
> linux_resume:
> already continuing LWP 97 at GDB's request
> Resuming, no pending status or step over needed
> linux_resume done
> <<<< exiting virtual void linux_process_target::resume(thread_resume*, size_t)
>>>>> entering ptid_t linux_process_target::wait_1(ptid_t, target_waitstatus*, target_wait_flags)
> wait_1: [Process 97]
> LWFE: waitpid(-1, ...) returned 0, ERRNO-OK
> RSRL: resuming stopped-resumed LWP LWP 97.97 at 0: step=0
> Resuming lwp 97 (continue, signal 0, stop not expected)
> leader_pid=97, leader_lp!=NULL=1, num_lwps=1, zombie=0
> sigsuspend'ing
> sigchld_handler
> LWFE: waitpid(-1, ...) returned 97, ERRNO-OK
> LLW: waitpid 97 received SIGTRAP - Trace/breakpoint trap (stopped)
> LWFE: waitpid(-1, ...) returned 0, ERRNO-OK
> Hit a non-gdbserver trap event.
>>>>> entering void linux_process_target::stop_all_lwps(int, lwp_info*)
> stop_all_lwps (stop, except=none)
> wait_for_sigstop: pulling events
> LWFE: waitpid(-1, ...) returned 0, ERRNO-OK
> leader_pid=97, leader_lp!=NULL=1, num_lwps=1, zombie=0
> LLW: exit (no unwaited-for LWP)
> stop_all_lwps done, setting stopping_threads back to !stopping
> <<<< exiting void linux_process_target::stop_all_lwps(int, lwp_info*)
> Checking whether LWP 97 needs to move out of the jump pad...no
> wait_1 ret = LWP 97.97, 1, 5
> <<<< exiting ptid_t linux_process_target::wait_1(ptid_t, target_waitstatus*, target_wait_flags)
> Process /bin/ls created; pid = 97
> Writing resume reply for LWP 97.97:1
> putpkt ("$T0500:0*"00;0e:0*"00;0f:0*"00;10:0*"00;thread:p61.61;core:0;#90"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("qAttached:61");  [sending ack]
> [sent ack]
> putpkt ("$0#30"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("qXfer:exec-file:read:61:0,1000");  [sending ack]
> [sent ack]
> putpkt ("$l/usr/bin/busybox#98"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("vFile:setfs:0");  [sending ack]
> [sent ack]
> putpkt ("$F0#76"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("vFile:open:6a7573742070726f62696e67,0,1c0");  [sending ack]
> [sent ack]
> putpkt ("$F-1,2#02"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("vFile:setfs:61");  [sending ack]
> [sent ack]
> putpkt ("$F0#76"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("vFile:open:2f7573722f62696e2f62757379626f78,0,0");  [sending ack]
> [sent ack]
> putpkt ("$F4#7a"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("vFile:pread:4,47ff,0");  [sending ack]
> [sent ack]
> putpkt ("$F4734;ELF"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("vFile:pread:4,47ff,1ce288");  [sending ack]
> [sent ack]
> putpkt ("$F370;"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("vFile:fstat:4");  [sending ack]
> [sent ack]
> putpkt ("$F40;"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("vFile:pread:4,47ff,34");  [sending ack]
> [sent ack]
> putpkt ("$F4733;"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("vFile:pread:4,47ff,1ce1a1");  [sending ack]
> [sent ack]
> putpkt ("$F457;"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("vFile:pread:4,47ff,b4");  [sending ack]
> [sent ack]
> putpkt ("$F4733;"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("vFile:fstat:4");  [sending ack]
> [sent ack]
> putpkt ("$F40;"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("vFile:open:2f7573722f62696e2f62757379626f78,0,0");  [sending ack]
> [sent ack]
> putpkt ("$F5#7b"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("vFile:pread:5,47ff,0");  [sending ack]
> [sent ack]
> putpkt ("$F4734;ELF"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("vFile:pread:5,47ff,1ce288");  [sending ack]
> [sent ack]
> putpkt ("$F370;"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("vFile:fstat:5");  [sending ack]
> [sent ack]
> putpkt ("$F40;"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("vFile:pread:5,47ff,34");  [sending ack]
> [sent ack]
> putpkt ("$F4733;"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("vFile:pread:5,47ff,1ce1a1");  [sending ack]
> [sent ack]
> putpkt ("$F457;"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("vFile:pread:5,47ff,b4");  [sending ack]
> [sent ack]
> putpkt ("$F4733;"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("vFile:fstat:5");  [sending ack]
> [sent ack]
> putpkt ("$F40;"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("qSymbol::");  [sending ack]
> [sent ack]
> Trying host libthread_db library: libthread_db.so.1.
> dlopen failed: libthread_db.so.1: cannot open shared object file: No such file or directory.
> thread_db_load_search returning 0
> putpkt ("$OK#9a"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("qSymbol::");  [sending ack]
> [sent ack]
> Trying host libthread_db library: libthread_db.so.1.
> dlopen failed: libthread_db.so.1: cannot open shared object file: No such file or directory.
> thread_db_load_search returning 0
> putpkt ("$OK#9a"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("qXfer:exec-file:read:61:0,1000");  [sending ack]
> [sent ack]
> putpkt ("$l/usr/bin/busybox#98"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("qOffsets");  [sending ack]
> [sent ack]
> putpkt ("$#00"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("Hgp61.61");  [sending ack]
> [sent ack]
> putpkt ("$OK#9a"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("qXfer:features:read:target.xml:0,1000");  [sending ack]
> [sent ack]
> putpkt ("$l<?xml version="1.0"?>
> <!DOCTYPE target SYSTEM "gdb-target.dtd">
> <target>
>   <architecture>pu32</architecture>
>   <osabi>GNU/Linux</osabi>
>   <feature name="org.gnu.gdb.pu32.core">
>  * <reg name="sp" bitsize="32" type="uint32" regnum="0"/>
>  * <reg name="r1" bitsize="32" type="uint32" regnum="1"/>
>  * <reg name="r2" bitsize="32" type="uint32" regnum="2"/>
>  * <reg name="r3" bitsize="32" type="uint32" regnum="3"/>
>  * <reg name="r4" bitsize="32" type="uint32" regnum="4"/>
>  * <reg name="r5" bitsize="32" type="uint32" regnum="5"/>
>  * <reg name="r6" bitsize="32" type="uint32" regnum="6"/>
>  * <reg name="r7" bitsize="32" type="uint32" regnum="7"/>
>  * <reg name="r8" bitsize="32" type="uint32" regnum="8"/>
>  * <reg name="r9" bitsize="32" type="uint32" regnum="9"/>
>  * <reg name="r10" bitsize="32" type="uint32" regnum="10"/>
>  * <reg name="r11" bitsize="32" type="uint32" regnum="11"/>
>  * <reg name="r12" bitsize="32" type="uint32" regnum="12"/>
>  * <reg name="r13" bitsize="32" type="uint32" regnum="13"/>
>  * <reg name="r14" bitsize="32" type="uint32" regnum="14"/>
>  * <reg name="r15" bitsize="32" type="uint32" regnum="15"/>
>  * <reg name="pc" bitsize="32" type="uint32" regnum="16"/>
>   </feature>
> </target>
> #ef"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("vFile:pread:4,47ff,b4");  [sending ack]
> [sent ack]
> putpkt ("$F4733;"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("g");  [sending ack]
> [sent ack]
> putpkt ("$x*}x*C#04"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("qXfer:libraries-svr4:read::0,1000");  [sending ack]
> [sent ack]
> putpkt ("$E01#a6"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("qXfer:auxv:read::0,1000");  [sending ack]
> [sent ack]
> putpkt ("$l"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("m50000034,20");  [sending ack]
> [sent ack]
> putpkt ("$010*050*"050f9cb1c00f9cb1c00050*"0010*!#ce"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("m50000054,20");  [sending ack]
> [sent ack]
> putpkt ("$010*"fccb1c00fcdb1c50fcdb1c50a5150* 1c370*!60*"0010*!#1c"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("m50000074,20");  [sending ack]
> [sent ack]
> putpkt ("$040*"b40*"b40* 50b40* 5020*"020*"0040*"040*"#58"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("m50000094,20");  [sending ack]
> [sent ack]
> putpkt ("$070*"fccb1c00fcdb1c50fcdb1c50180*"540*"040*"040*"#ff"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("m50000034,20");  [sending ack]
> [sent ack]
> putpkt ("$010*050*"050f9cb1c00f9cb1c00050*"0010*!#ce"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("m50000054,20");  [sending ack]
> [sent ack]
> putpkt ("$010*"fccb1c00fcdb1c50fcdb1c50a5150* 1c370*!60*"0010*!#1c"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("m50000074,20");  [sending ack]
> [sent ack]
> putpkt ("$040*"b40*"b40* 50b40* 5020*"020*"0040*"040*"#58"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("m50000094,20");  [sending ack]
> [sent ack]
> putpkt ("$070*"fccb1c00fcdb1c50fcdb1c50180*"540*"040*"040*"#ff"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("m50000034,20");  [sending ack]
> [sent ack]
> putpkt ("$010*050*"050f9cb1c00f9cb1c00050*"0010*!#ce"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("m50000054,20");  [sending ack]
> [sent ack]
> putpkt ("$010*"fccb1c00fcdb1c50fcdb1c50a5150* 1c370*!60*"0010*!#1c"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("m50000074,20");  [sending ack]
> [sent ack]
> putpkt ("$040*"b40*"b40* 50b40* 5020*"020*"0040*"040*"#58"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("m50000094,20");  [sending ack]
> [sent ack]
> putpkt ("$070*"fccb1c00fcdb1c50fcdb1c50180*"540*"040*"040*"#ff"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("m50000034,20");  [sending ack]
> [sent ack]
> putpkt ("$010*050*"050f9cb1c00f9cb1c00050*"0010*!#ce"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("m50000054,20");  [sending ack]
> [sent ack]
> putpkt ("$010*"fccb1c00fcdb1c50fcdb1c50a5150* 1c370*!60*"0010*!#1c"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("m50000074,20");  [sending ack]
> [sent ack]
> putpkt ("$040*"b40*"b40* 50b40* 5020*"020*"0040*"040*"#58"); [looking for ack]
> [received '+' (0x2b)]
> handling possible serial event
> getpkt ("m50000094,20");  [sending ack]
> [sent ack]
> putpkt ("$070*"fccb1c00fcdb1c50fcdb1c50180*"540*"040*"040*"#ff"); [looking for ack]
> [received '+' (0x2b)]
>
> root@buildroot:~