Fuxin Zhang wrote on Fri, 25 May 2012:
And my progress and problems: I've got the source from subversion and tried to build it in ubuntu 11.10 x86-64 machine. With the following patch and commands, I can get a partly working ppcrossmipsel(it can at least build a helloworld and runnable): patch: Index: Makefile.fpc =================================================================== --- Makefile.fpc (版本 21354) +++ Makefile.fpc (工作副本)
[snip]
This is to fix various file not found errors. I am not sure whether it is 'right' fix.
No, definitely it's definitely not right. It's strange that you need those changes, since the Linux RTL Makefile is used daily. Did you need those changes even to compile it for i386?
commands: cd rtl/linux; patch Makefile.fpc; fpcmake -Ti386-linux,mipsel-linux
It's better to use -Tall (since there are more Linux targets than just i386 and mipsel).
/home/foxsen/fpc/rtl/units/mipsel-linux/sysutils.o: In function `SYSUTILS_$$_finalize': /home/foxsen/fpc/rtl/unix/sysutils.pp:1414: relocation truncated to fit: R_MIPS_PC16 against `SYSTEM$_$TINTERFACEDOBJECT_$__$$_QUERYINTERFACE$TGUID$formal$$LONGINT' /home/foxsen/fpc/rtl/unix/sysutils.pp:1414: relocation truncated to fit: R_MIPS_PC16 against `SYSTEM$_$TINTERFACEDOBJECT_$__$$__ADDREF$$LONGINT' /home/foxsen/fpc/rtl/unix/sysutils.pp:1414: relocation truncated to fit: R_MIPS_PC16 against `SYSTEM$_$TINTERFACEDOBJECT_$__$$__RELEASE$$LONGINT' pp.pas(224,36) Error: Error while linking pp.pas(224,36) Fatal: There were 1 errors compiling module, stopping Fatal: Compilation aborted> make[1]: *** [ppcmipsel] 错误 1 make[1]:正在离开目录 `/home/foxsen/fpc/compiler' make: *** [cycle] 错误 2 I know it is related to mips branch offset overflow.
A similar issue exists on PowerPC: conditional branches are limited to 16 bit offsets, while unconditional branches can reach up to 26 bits or so. As far as I can see, it's similar on MIPS (the B* opcodes versus the J opcode). If so, you may be able to create a MIPS version of the fixup_jmps procedure in compiler/ppcgen/aasmcpu.pas and add it to compiler/mips/aasmcpu.pas (it's called from psub.pas, you'll have to modify the ifdef there to also activate it for MIPS and MIPSEL). The actual errors you get are strange though. We never insert conditional branches from one routine to another (in the above case: from SYSUTILS_$$_finalize, or more likely from interface wrappers following that symbol, to various other routines). Looking at the code for tcgcpu.g_intf_wrapper in compiler/mips/cgcpu.pas, the code for interface wrappers uses the "B" as opposed to the "J" instruction to branch to the interface wrappers. Maybe that's a copy/paste error from another platform. I'm not sure what "B" means though, I don't see it listed at http://www.mrc.uidaho.edu/mrc/people/jff/digital/MIPSir.html Anyway, I guess this patch will solve the above error: Index: compiler/mips/cgcpu.pas =================================================================== --- compiler/mips/cgcpu.pas (revision 21359) +++ compiler/mips/cgcpu.pas (working copy) @@ -1722,7 +1722,7 @@ op_onr24methodaddr; end else - list.concat(taicpu.op_sym(A_B,current_asmdata.RefAsmSymbol(procdef.mangledname))); + list.concat(taicpu.op_sym(A_J,current_asmdata.RefAsmSymbol(procdef.mangledname))); { Delay slot } list.Concat(TAiCpu.Op_none(A_NOP));
After some research,I've found that ppc code support -fPIC.
PIC normally won't help with branch offset overflows.
But when I try to enable it,the other issue appears:
Yes, PIC requires cpu-specific support. It shouldn't be necessary to get an initial port up and running though. Jonas _______________________________________________ fpc-devel maillist - fpc-devel@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-devel
