someone guide me to continue work on mips64el

[cai]

I use FPC Trunk & binutils 2.40 to build ppcross compiler, I know it is incompleted.
for now,  build rtl error info：
-----------------------------------------------------
H:/fpcupdeluxe/fpc/bin/i386-win32/ppcrossmips64el.exe -Ur -Tlinux -Pmips64el -XPmips64el-linux- -Ur -Xs -O2 -n -Fi../inc -Fi../mips64el -Fi../unix -Fimips64el -FDH:\fpcupdeluxe\cross\bin\mips64el-linux -FE. -FUH:/fpcupdeluxe/fpcsrc/rtl/units/mips64el-linux -Cg -vw-n-h-l-d-u-t-p-c- -dmips64el -dRELEASE -XPmips64el-linux- -Xd -FlH:\fpcupdeluxe\cross\lib\mips64el-linux  -Us -Sg system.pp
flt_core.inc(1567,1) Fatal: Internal error 2002122100
Fatal: Compilation aborted
=====================================
1. error 2002122100 related-code
------------------------------

Code: Pascal  [Select][+][-]

1. procedure TCGMIPS.a_load_reg_ref(list: tasmlist; FromSize, ToSize: TCGSize; reg: tregister; const Ref: TReference);
2. var
3.   op: tasmop;
4.   href: treference;
5. begin
6.   if (TCGSize2Size[fromsize] < TCGSize2Size[tosize]) then
7.     a_load_reg_reg(list,fromsize,tosize,reg,reg);
8.   if (ref.alignment<>0) and
9.      (ref.alignment<tcgsize2size[tosize]) then
10.     begin
11.       a_load_reg_ref_unaligned(list,FromSize,ToSize,reg,ref);
12.       exit;
13.     end;
14.   case tosize of
15.     OS_8,
16.     OS_S8:
17.       Op := A_SB;
18.     OS_16,
19.     OS_S16:
20.       Op := A_SH;
21.     OS_32,
22.     OS_S32:
23.       Op := A_SW;
24.     OS_64,
25.     OS_S64:
26.       Op := A_SD;
27.     else
28.       InternalError(2002122100);
29.   end;
30.   href:=ref;
31.   make_simple_ref(list,href);
32.   list.concat(taicpu.op_reg_ref(op,reg,href));
33. end;  
34.  

2. flt_core.inc(1567,1)
-------------------------------

Code: Pascal  [Select][+][-]

1.     one_e: integer;
2.     one_mask, f: dword;
3.     buf: TAsciiDigits;
4.  
5. begin // line 1567
6.  
7.     // Limit parameters
8.     if ( frac_digits > 216 ) then
9.         frac_digits := 216; // Delphi compatible
10.     if ( min_width <= C_NO_MIN_WIDTH ) then
11.         min_width := -1 // no minimal width
12.  

now my question is, How to proceed with the next modification work?
just a hobby in my spare time，thanks for any guide!