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Hi, I am trying to debug a multithreaded program running on an embedded MIPS 5Kc using gdb and gdbserver, connected via a serial port. My environment is as follows: MIPS kernel based on 2.4.18 gdb : 6.2.1, configured with --host=i686-pc-linux-gnu --target=mips-hardhat-linux --disable-sim --disable-tcl --enable-threads --enable-shared gdbserver: 6.2.1, configured with --target=mips-linux --enable-threads --enable-shared gcc : 3.2.3, } binutils : 2.13 } Built using crosstool glibc: 2.2.5 } My problems are as follows: 1) If I try to run the program from gdbserver (i.e. gdbserver /dev/ttyS0 wlsd), I get "readchar: Input/output error" messages, and nothing works. See attached file gdb_fail. What is going on here ? 2) If I first run the program, and then attach gdbserver to it (i.e. gdbserver /dev/ttyS0 --attach 80), I can debug it. However, debugging is amazingly slow !! For example, it can take 10 minutes for the "backtrace" (bt) command to complete !!! Also, I get messages saying "Cannot access memory at address 0x2c" whnever I try to look at the stack. See attached file gdb_trace. Why is it going so slow ? What is the cause of the "Cannot access memory at address 0x2c" messages ? 3) If I repeat the scenario described in 2), but with "set debug remote 1", it seems to work somewhat faster (e.g. bt takes about 1 minute to complete). I am seeing alot of "Packet instead of Ack, ignoring it" messages. See attached file gdb_trace_debug. What do these messages mean ? In general, what to I need to do to get gdb <-> gdbserver debugging working properly over a serial port? Thanks in advance for any tips !! -Yoni
<<gdb_fail>> <<gdb_trace_debug>> <<gdb_trace>>
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