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
