Thanks Maarten,
I think I understand the cause of the misordering in the linker now.
The object file containing the main routine was brought in from a
library file instead of listed on the link command line. I have it
working now by listing the main on the link command.
I am using a commerical programmer called flashpro-cc. I will contact
their support to find out if they can handle the unsorted/extended intel
hex files.
Maarten Brock wrote:
Hi Anthony,
It seems bankswitching is broken. And you also found why
already: the startup routine should be at 0x0000 and
__sdcc_banked_call at some higher address. Does it help
if you put the .rel which contains main() as the first
object to link?
Programmers that cannot handle unsorted hex-files are
too restrictive. There is nothing about sorting in the
definition of the standard.
Parameter passing should be taken care of correctly.
Sorry for the late reply. I had a busy weekend.
Maarten
Based on the lack of responses, and the branches of sdcc with
modifications to fix bank switching, I believe the banking in the
official version is broken. The documentation should be updated to
indicate this so future users don't waste their time trying to use it.
The branched version are not keeping up with the latest sdcc releases,
they only support 2.7.0 and 2.8.0.
If you are curious you should look at this sdcc branch, modified "with
banking"
http://sourceforge.net/projects/ccflasher/files/
If there is any way to make the bank switching work in the mainline
code, I am willing to help test and document it.
Anthony
Anthony Asterisk wrote:
Hello SDCC-users,
From reading the sdcc documentation, bank switching for the mcs51 is
supported through the sdcc specific keyword __banked, a codeseg
command line switch (or inline pragma) and the trampoline calls
__sdcc_banked_call and __sdcc_banked_ret. The cc2430 chip that I am
using provides a bank switching SFR called FMAP that is functionally
similar to the crtbank.asm examples PSBANK, therefore I expect the
crtbank.asm trampoline should work with no changes. However when I
mark any routine as banked, even if it is in the HOME bank, the code
does not work...
Changes that I notice when using banking:
The trampoline functions get added to final map file (demo.map)
Area Addr Size Decimal Bytes
(Attributes)
-------------------------------- ---- ---- ------- -----
------------
HOME 0000 00AC = 172. bytes
(REL,CON,CODE)
Value Global
-------- --------------------------------
0C:0000 __sdcc_banked_call
0C:0016 __sdcc_banked_ret
0C:009F __sdcc_program_startup
0C:00A4 __sdcc_call_dptr
0C:00A6 _hello_world
** Is the location of __sdcc_banked_call at address 0000 in the HOME
segment a problem? I expected the start up routines would normally go
at 0000.
** From discussions with some other users of the cc2430/sdcc, it seems
the banked mode does not work as described in the documentation.
Specifically, I have been informed of some undocumented requirements...
- generated hex file is in an unusual format that is not compatible
with "commercial" programmers and must converted somehow
- all code must be assigned to a bank, it will not work if any code
is unassigned
- all banks must have some code assigned to it
** Does anyone have the documented approach to bank switching
working? Is there some source code online that I can study?
** If the documented method does not work, I would be willing to help
update the documentation if someone can explain the current
requirements and implementation.
Here are the bank switching assembly routines...
.area HOME (CODE)
__sdcc_banked_call::
push _PSBANK ;save return bank
xch a,r0 ;save Acc in r0, do not assume any
register bank
push acc ;push LSB address
mov a,r1
push acc ;push MSB address
mov a,r2 ;get new bank
anl a,#0x0F ;remove storage class indicator
anl _PSBANK,#0xF0
orl _PSBANK,a ;select bank
xch a,r0 ;restore Acc
ret ;make the call
__sdcc_banked_ret::
pop _PSBANK ;restore bank
ret ;return to caller
Generated assembly code for a banked call:
; demo.c:82: abc=hello_world();
mov r0,#_hello_world
mov r1,#(_hello_world>> 8)
mov r2,#(_hello_world>> 16)
lcall __sdcc_banked_call
mov r2,dpl
mov r3,dph
; hello_world.c:15: return 123;
mov dptr,#0x007B
ljmp __sdcc_banked_ret
Questions:
- the parameters passed on the stack to banked routine would come
before _PSBANK. Will the banked routine skip over the stored _PSBANK
to reach them? So far I have only attempted to routines without
parameters.
------------------------------------------------------------------------------
Return on Information:
Google Enterprise Search pays you back
Get the facts.
http://p.sf.net/sfu/google-dev2dev
_______________________________________________
Sdcc-user mailing list
Sdcc-user@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/sdcc-user
------------------------------------------------------------------------------
Return on Information:
Google Enterprise Search pays you back
Get the facts.
http://p.sf.net/sfu/google-dev2dev
_______________________________________________
Sdcc-user mailing list
Sdcc-user@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/sdcc-user
------------------------------------------------------------------------------
This SF.Net email is sponsored by the Verizon Developer Community
Take advantage of Verizon's best-in-class app development support
A streamlined, 14 day to market process makes app distribution fast and easy
Join now and get one step closer to millions of Verizon customers
http://p.sf.net/sfu/verizon-dev2dev
_______________________________________________
Sdcc-user mailing list
Sdcc-user@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/sdcc-user
