[Fx2lib-devel] Setupdata at 0xe000

[Daniel O'C. <doc...@gs...>]

Hi,
I recently found myself running out of space on my FX2 firmware so I did a bit of remapping things to squeeze out some more room.

One thing I did was to put the descriptors at 0xe000 and this worked, however I found that string descriptors didn't work.

After bashing my head against the desk for a bit I realised it was because they are declared as __code rather than __xdata. The device descriptor still works because (I think) it uses SUDPTRH/L.

I have the following diff..
Index: lib/setupdat.c
===================================================================
RCS file: /usr/local/Genesis/cvs/micro/lib/fx2lib/lib/setupdat.c,v
retrieving revision 1.1.1.1
diff -u -p -r1.1.1.1 setupdat.c
--- lib/setupdat.c	26 Feb 2011 06:40:02 -0000	1.1.1.1
+++ lib/setupdat.c	16 Sep 2011 08:15:34 -0000
@@ -271,11 +271,14 @@ BOOL handle_set_feature() {
 /* these are devined in dscr.asm
    and need to be customized then
    linked in by the firmware manually */
-extern __code WORD dev_dscr;
-extern __code WORD dev_qual_dscr;
-extern __code WORD highspd_dscr;
-extern __code WORD fullspd_dscr;
-extern __code WORD dev_strings;
+#ifndef DSCR_ADDRSPACE
+#define DSCR_ADDRSPACE __code
+#endif
+extern DSCR_ADDRSPACE WORD dev_dscr;
+extern DSCR_ADDRSPACE WORD dev_qual_dscr;
+extern DSCR_ADDRSPACE WORD highspd_dscr;
+extern DSCR_ADDRSPACE WORD fullspd_dscr;
+extern DSCR_ADDRSPACE WORD dev_strings;
 
 WORD pDevConfig = (WORD)&fullspd_dscr;
 WORD pOtherConfig = (WORD)&highspd_dscr;

To go with this I have a local only diff to modify SDCCFLAGS in lib/Makefile to set it.

My earlier changes where to build code with..
CFLAGS=        -mmcs51 --code-size 0x3e00 --xram-size 0x0100 --xram-loc 0x3e00 --stack-auto
LDFLAGS=       -Wl"-b DSCR_AREA=0xe000" -Wl"-b INT2JT=0x3f00" 

ie I cut RAM in half after checking the SDCC report.

Also it seems that the 'default' (i.e. what's in the examples) --xram-loc is conservative.

--
Daniel O'Connor software and network engineer
for Genesis Software - http://www.gsoft.com.au
"The nice thing about standards is that there
are so many of them to choose from."
  -- Andrew Tanenbaum
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