RE: [ECOS] Building rommable images for the AEB-1C

[Gary Thomas <gthomas@cygnus.co.uk>]

On 06-Jan-00 Nicholas_Clarey@ivesco.co.uk wrote:
> Howdy all,
> 
> I've been trying to create an image that I can put into the Arm Evaluation 
> 
> Board flash rom so that I can take over the serial port and play with it. 
> Unfortunately, it's not working.
> 
> I have managed the first stage of producing the CVS gdb stubs and flashed 
> them successfully, and have written test programs, downloaded them and 
> played with them fine. I followed all the necessary instructions in the 
> documentation to do this.
> 
> Here's what I've done so far;
> 
> - produced the build directory with the following command;
> 
> tclsh BASE_DIR/packages/pkgconf.tcl --target=arm 
> --platform=aebC--startup=rom
> 
> which I figured would do what was necessary to give me libraries and stuff 
> 
> I could link with and place in ROM rather than RAM.
> 
> - edited the pkgconf/serial_io.h header file to enable the serial port(s) 
> by #defining the aeb serial port stuff
> - run "make"
> - wrote a simple c program that opened the serial port and dumped some 
> trivial data to it
> 
> When I try to compile the c program in the last step, I did the following;
> 
> arm-elf-gcc -Iinstall/include testfile.c -Linstall/lib -Ttarget.ld 
> -nostdlib
> 
> and I get two errors and two warnings;
> 
> testfile.c: In function `cyg_user_start':
> testfile.c:32: warning: passing arg 4 of `cyg_io_set_config' makes pointer 
> 
> from integer without a cast
> testfile.c:37: warning: passing arg 3 of `cyg_io_write' makes pointer from 
> 
> integer without a cast

I'd have to see your sources to know exactly why you get these warnings.
However, they are from the compiler, telling you that you are apparently not
passing the correct "type" of information to the cyg_io_XXX() functions.

The severity of such missuse can range from being totally benign to complete
failure.  In particular, the second warning says that you've passed an integer
and not a pointer as the third parameter to 'cyg_io_write()'.  This parameter
must be a pointer to the length, not the length itself.  This is because the
function returns the actual number of bytes written in the variable, in case
it differed for some reason from the requested number.

> /usr/cygnus/ecosSWtools-arm-990321/i686-pc-linux-gnu/lib/gcc-lib/arm-elf/2.9 
> 
> -ecosSWtools-arm-990321/../../../../arm-elf/bin/ld: address 0x40219ac of 
> a.out section .text is not within region rom
> /usr/cygnus/ecosSWtools-arm-990321/i686-pc-linux-gnu/lib/gcc-lib/arm-elf/2.9 
> 
> -ecosSWtools-arm-990321/../../../../arm-elf/bin/ld: address 0x4021c34 of 
> a.out section .rodata is not within region rom

If you look at the ROM layout, you'll see that it is only set up to handle
small programs in the flash/ROM.  The default setup is for 32K (0x8000) bytes
at the end of the flash.  The flash on that board is quite limited (128K) and
we didn't want to destroy what was already there (the boot loader, etc).

> /usr/cygnus/ecosSWtools-arm-990321/i686-pc-linux-gnu/lib/gcc-lib/arm-elf/2.9 
> 
> -ecosSWtools-arm-990321/../../../../arm-elf/bin/ld: warning: no memory 
> region specified for section `.glue_7'
> /usr/cygnus/ecosSWtools-arm-990321/i686-pc-linux-gnu/lib/gcc-lib/arm-elf/2.9 
> 
> -ecosSWtools-arm-990321/../../../../arm-elf/bin/ld: warning: no memory 
> region specified for section `.glue_7t'

I don't understand these warnings at all [yes, I know what they mean, I just
don't know how you created them].  

What compiler/toolset are you using?
Did you use any special compiler options when building the program?

The other thing to note about running programs in flash/ROM on the AEB is that
eCos assumes that the ARM bootloader is in place, even for these.  This means
that you'll need to set up a flash image "module" which follows the ARM rules.
This is a rather tricky process and not terribly simple to automate.  You
can look at ".../hal/arm/aeb/XXX/misc/PKGconf.mak" to see how it is done for
the GDB stubs.