Re: [ECOS] loading application on redboot

["Michael Anburaj" <embeddedeng at hotmail dot com>]

I use GDB at 115200.

In one of your earlier emails you said that Redboot/GDB did not respond to 
"$#00". If this does not work, then there is no way that GDB could work.

I faced the same problem earlier. When Redboot sees the 1st ?$?, its gona 
load the context for trampoline() using hal_thread_load_context() os 
arm/arch/src/context.S

code form /redboot/src/main.c:

HAL_THREAD_INIT_CONTEXT((CYG_ADDRESS)workspace_end, breakpoint, trampoline, 
0); // switch context to trampoline (get GDB stubs started) 
HAL_THREAD_SWITCH_CONTEXT(&saved_context, &workspace_end);

The last instruction at hal_thread_load_context(),
movs    pc,lr

is going to load the CPSR with SPSR, which has the I ? bit set. So if you 
have any pending unattached (or not configured), unexpected interrupts, then 
the processor will branch to an ISR that?s not there (in my case I had the 
RTC ISR pending ? if you need more info. check the emails by me 2 months 
earlier on this forum). I advice you to investigate all the key registers 
just before this last instruction ?movs    pc,lr? is taken. & Follow the 
flow further down using a JTAG probe.

Cheers,
-Mike.

-Mike.


> From: Satish Kumar <satish@bvt.sc.sanyo.co.jp>
> To: "Michael Anburaj" <embeddedeng@hotmail.com>
> CC: ecos-discuss@sources.redhat.com
> Subject: Re: [ECOS] loading application on redboot
> Date: Fri, 01 Aug 2003 17:36:22 +0900
>
> i was just wondering if gdb fails to work on 115200 baudrate, coz the
> gdb fails to connect even after setting the baudrate to 115200.
>
> satish
>
>
> On Fri, 01 Aug 2003 08:31:36 +0000
> "Michael Anburaj" <embeddedeng@hotmail.com> wrote:
>
> > Yea,
> >
> > open gdb with -w (insight) & you can set the baud rate at target 
> settings,
> >
> > $ arm-elf-gdb -w hello
> >
> > or if you open the text gdb
> >
> > gdb> set remotebaud 115200
> >
> > -Mike.
> >
> > >From: Satish Kumar <satish@bvt.sc.sanyo.co.jp>
> > >To: Jonathan Larmour <jifl@eCosCentric.com>
> > >CC: Michael Anburaj
> > ><embeddedeng@hotmail.com>,ecos-discuss@sources.redhat.com
> > >Subject: Re: [ECOS] loading application on redboot
> > >Date: Fri, 01 Aug 2003 17:22:50 +0900
> > >
> > >well, actually my serial driver is set to baudrate 115200..
> > >will the GDB work on this baudrate..?
> > >
> > >satish
> > >
> > >
> > >On Fri, 01 Aug 2003 05:34:08 +0100
> > >Jonathan Larmour <jifl@eCosCentric.com> wrote:
> > >
> > > > Satish Kumar wrote:
> > > > > Hi,
> > > > >
> > > > >     using hyperteminal i have downloaded hello.srec at 0x40000 and
> > >this
> > > > > time when i tried "go 0x40040" redboot hangs..i see no output on 
> the
> > > > > hyper terminal.
> > > > >
> > > > > btw, i tried another method i.e using arm-elf-gdb..after powering 
> on
> > >my
> > > > > system, on "arm-elf-gdb -nw hello" ;i get the following output:
> > > > >
> > > > > $ arm-elf-gdb -nw hello
> > > > > GNU gdb 5.3 (eCosCentric)
> > > > > Copyright 2002 Free Software Foundation, Inc.
> > > > > GDB is free software, covered by the GNU General Public License, 
> and
> > >you are
> > > > > welcome to change it and/or distribute copies of it under certain
> > >conditions.
> > > > > Type "show copying" to see the conditions.
> > > > > There is absolutely no warranty for GDB.  Type "show warranty" for
> > >details.
> > > > > This GDB was configured as "--host=i686-pc-cygwin 
> --target=arm-elf"...
> > > > > (gdb) target remote com1
> > > > > Remote debugging using com1
> > > > > Ignoring packet error, continuing...
> > > > > Ignoring packet error, continuing...
> > > > > Ignoring packet error, continuing...
> > > > > Couldn't establish connection to remote target
> > > > > Malformed response to offset query, timeout
> > > > > (gdb) quit
> > > > >
> > > > > i m not sure if the problem is with building  application or with
> > > > > the redboot_ROM monitor.
> > > >
> > > > This probably means your application isn't built for the right 
> address
> > >in
> > > > RAM. Do arm-elf-objdump -h on the (ELF) executable to see what the 
> load
> > > > address is, and compare that against your memory map.
> > > >
> > > > Jifl
> > > > --
> > > > eCosCentric    http://www.eCosCentric.com/    The eCos and RedBoot
> > >experts
> > > > --[ "You can complain because roses have thorns, or you ]--
> > > > --[  can rejoice because thorns have roses." -Lincoln   ]--
> > >Opinions==mine
> > >
> > >--
> > >Satish Kumar <satish@bvt.sc.sanyo.co.jp>
> > >
> >
> > _________________________________________________________________
> > MSN 8 helps eliminate e-mail viruses. Get 2 months FREE*.
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>
> --
> Satish Kumar <satish@bvt.sc.sanyo.co.jp>
>
>
> --
> Before posting, please read the FAQ: http://sources.redhat.com/fom/ecos
> and search the list archive: http://sources.redhat.com/ml/ecos-discuss

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