[ECOS]Debugger fails when I add kernel support

Sergei Gavrikov sergei.gavrikov@gmail.com
Tue Apr 7 16:44:00 GMT 2009

On Tue, Apr 07, 2009 at 04:40:42PM +0200, Robert Brusa wrote:
> On Tue, 07 Apr 2009 16:01:35 +0200, Sergei Gavrikov  
> <sergei.gavrikov@gmail.com> wrote:
>> On Tue, Apr 07, 2009 at 02:58:44PM +0200, Robert Brusa wrote:
>>> On Mon, 06 Apr 2009 23:39:24 +0200, Sergei Gavrikov
>>> <sergei.gavrikov@gmail.com> wrote:
>>> ..<cut>
>>> >>Robert, of course, the right way is to define own macro (= CDL 
>>> rule) in
>>> >>the plf's stuff. But, that's not possible without a tweaking plf's  
>>> code.
>>> >>I thought about a froud hack: to add something like the below in  
>>> >>
>>> >>    -D"HAL_IDLE_THREAD_ACTION(x)={}"
>>> >>
>>> >>Well, it's ugly, but, if you do not want to mess up 3.0 sources, it
>>> >>would
>>> >>be a way.
>>> >>
>>> >>Perhaps, eCos veterans know about another way.
>>> >>
>>> >
>>> >It's just for reference how it was done for lpc2xxx variants:
>>> >packages/hal/arm/lpc2xxx/var/current/include/var_arch.h:63
>>> >
>>> >So, I can use
>>> >
>>> >    user_value 0
>>> >};
>>> >
>>> >for my target to disable that "odd" mode. Certainly it can be disabled
>>> >with `configtool' too.
>>> >
>>> >Sergei
>>> Sergei, I did it with brutal force: I modified the lines inside  
>>> var_arch.h
>>> in directory ecos/packages/hal/arm/at91/var/current/include such that 
>>> the
>>> macro
>>> HAL_IDLE_THREAD_ACTION(_counter_) is no longer generated. Then I  
>>> created a
>>> new ecos and linked my little project with this new ecos. The results 
>>> are
>>> mixed:
>>> a) As before, when switching power on with no JTAG debugger (BDI2000)
>>> connected, the program launches and works fine.
>>> b) With the JTAG debugger connected, I am no longer in a position to
>>> launch it with the BDI go 0 command (via telnet). No output at all.
>> IMHO, it is a JTAG issue, jtag cannot halt CPU. Usually, they recommend
>> that your early startup has a loop in assembler during a few time to
>> give a chance JTAG halt CPU. A few ms it's enougth. You can put this in
>> your hal_platform_startup.s (before any initialization, it should be
>> just a loop in asm).
> ==> The BDI is configured to stop the target when it comes out of reset.  
> And that it does wunderfully. I then click the run button and that's were 
> the problems start :-(
>>> c) I can set breakpoints in cyg_user_start and the output of the
>>> diag_printf statement in this routine appear - but
>>>    the output of the diag_printf routines in the thread created and
>>> resumed from this reoutine do not appear - although I can catch
>>>    breakpoints in this thread.
>>> Not a very clear situation. Do you have a good idea? Thanks and regards
>>>    Robert
>> diag_printf() is good for asserts, diagnostic output, etc., i.e. for
>> debugging only. What is a reason to use it inside the threads?
>> every plf. diagnostic "putc" is something like this blocking loop:
>> 	do {
>> 	    // check UART status
>> 	} while (!can_send);
>> It's not good for multi-threads applications. It blocks eCos, so, use
>> printf() inside the threads, interrupt-driven and non-blocking serial
>> I/O. Use a mutex to share printf() between the threads. I do not think
>> that eCos's the floating-points-less printf() is heavy stuff. Robert,
>> that is just my thoughts about your implementation. This is not JTAG
>> related things.
>> Sergei
> Hi Sergei
> Well, I used to have printf-statements in all my programs. But since  
> working with the new arm-eabi toolchain, I found that all my programs  
> crash in this printf statement. I reported this in the arm_gnu forum, but 
> got no useful answer. :-(
> Right now I have kicked out all diag_printf statements in the thread and  
> put printf instead - No output in no case.
> Then I changed it to fprintf(... and already the statement
> fuser = fopen("/dev/ser1", "w");
> comes back with fuser == 0 - even so I enabled ser0 and ser1 - the  
> interrupt driven version at91serial - in configtool ...
> Something very basic must be wrong in my case. If only I knew what??????  
> :-(
>   Robert

I'm sure that is not "arm_gnu" related, something is wrong witch eCos
configuration. Forget about own application. You have to make work two
famous eCos examples for your target: these are `twotreads' and `serial'
(see $ECOS_REPOSITORY/../examples). Twothreads is exactly that what you
need. First, it's hardy help using a `configtool' way. I'm sorry. BUT, I
will try. What's your target's name exactly?  (It seems I missed the
name). As I could understand you use ROM startup and the target has at
the least two serial ports.

$ ecosconfig new <target> default

At least, you have to set the below options to get non-blocking serial

    user_value 1

    user_value 1

Put the above in serial.ecm and import this file then.

$ ecosconfig import serial.ecm

About printf() channel...

$ less -p 'DEFAULT_CONSOLE \{' ecos.ecc

cdl_option CYGDAT_LIBC_STDIO_DEFAULT_CONSOLE sets a device name which
will be used for printf(). Set it properly (edit ecos.ecc).

$ ecosconfig resolve && ecosconfig tree && make -s

cp -a $ECOS_REPOSITORY/../examples .

make -C examples INSTALL_DIR=`pwd`/install twothreads 
make -C examples INSTALL_DIR=`pwd`/install serial 

There will be your test stuff under examples directory. Make twothreads
works with JTAG.

Note: I do not know about your target, if your default startup RAM, it's
possible you have to import and the below before to build eCos examples

cdl_component CYG_HAL_STARTUP {
    user_value ROM

Robert, only if you will manage `twothreads' then you will manage own


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