[Sdcc-user] SDCC DS390 Port and _sdcc_external_startup

[Arif M. <Ari...@sd...>]

Hello,

I have a hardware board with 80390 core. I want to use SDCC in ds390
flat42 (24 bit address) memory mode.

But I don't want to use tinibios and its startup code (tinibios has
_sdcc_external_startup, clock and serial port initialization).

I modified <SDCC>/device/examples/ds390/hello390.c to include my own
_sdcc_external_startup  (and clock and serial port ISRs for satisfying
linker dependencies).

The above mentioned hello390.c is compiled/linked using the following
command
------------------------------------------------------------------------
----------------------

sdcc --verbose -mds390 --xram-loc 0x00 --code-loc 0x00 \
		-Wl-r hello390.c --nostdlib
-l../../../lib/build/ds390/liblong.lib
-l../../../lib/build/ds390/libsdcc.lib
-l../../../lib/build/ds390/libfloat.lib
------------------------------------------------------------------------
----------------------

It generates hello390.ihx, which I am able to burn to my hw board's
flash (after converting to binary using hex2bin tool), but nothing
happens.

BTW, my main function in hello390.c is empty and I removed the printf
call as it was dependent on correct serial port initialization while I
am one step behind that for now.

All I want to know If my  _sdcc_external_startup   is called. This
function has nothing but clock init and controlling a LED using P1 SFR
output pin.
The assembly listing of the program shows that  _sdcc_external_startup
is linked but the debug LED mentioned in previous line does not glow
(actually nothing happens at all).

I hope somebody could point me in right direction.
Thank you.

PS:
I am new to micro controller programming though have been working with
ARM arch for some time.

Arif M
Singapore