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Simba/Units/PascalScript/arm.inc
2010-03-12 18:10:10 +01:00

313 lines
10 KiB
PHP

{ implementation of the arm procedure call standard for function calls in pascal script
Copyright (c) 2008 by Henry Vermaak (henry.vermaak@gmail.com)
todo: add eabi (define FPC_ABI_EABI) and wince support
notes:
most arm cpus don't allow unaligned access. by default (?) the linux kernel
is set up to try and correct unaligned access, which can lead to strange behaviour.
to turn this off, try (as root):
echo 4 > /proc/cpu/alignment
if you have an alignment problem, you will now get a crash with a backtrace like this:
(make sure you compile with -O- -gl)
An unhandled exception occurred at $0006C014 :
EBusError : Bus error or misaligned data access
$0006C014 PROCESSREPEAT, line 9670 of upscompiler.pas
$00068AAC TPSPASCALCOMPILER__PROCESSSUB, line 10459 of upscompiler.pas
$0007D0B4 TPSPASCALCOMPILER__COMPILE, line 11704 of upscompiler.pas
you can fix this by using the "unaligned" keyword around the pointer operation.
search for occurances of "unaligned" to see how this is done,
(use $ifdef FPC_REQUIRES_PROPER_ALIGNMENT).
for more information, visit:
http://www.aleph1.co.uk/oldsite/armlinux/book/afaq.html
}
const
rtINT = 0;
rtINT64 = 1;
rtFLOAT = 2;
type
Trint = array[1..4] of dword;
Trfloat = array[1..4] of double;
{$goto on}
{ define labels }
label
stack_loop,
load_regs,
asmcall_end,
int_result,
int64_result,
float_result;
{ call a function from a pointer }
{ resulttype: 0 = int, 1 = int64, 2 = float }
function armasmcall(rint: Trint; rfloat: Trfloat; proc, stack: pointer; stacksize, resulttype: integer): pointer; assembler; nostackframe;
asm
mov r12, r13
stmfd r13!, {r4, r5, r6, r7, r8, r9, r10, r11, r12, r14, r15}
sub r11, r12, #4
mov r4, #80 (* space for preserved registers and parameters *)
ldr r5, [r11, #4] (* stacksize we need for subroutine *)
add r4, r4, r5
sub r13, r13, r4 (* create stack space *)
(* store parameters on stack *)
str r0, [r11, #-44] (* rint *)
str r1, [r11, #-48] (* rfloat *)
str r2, [r11, #-52] (* proc *)
str r3, [r11, #-56] (* stack *)
ldr r0, [r11, #4]
str r0, [r11, #-60] (* stacksize *)
ldr r0, [r11, #8]
str r0, [r11, #-64] (* resulttype *)
(* store params for sub-routine that don't fit into r0-r3 at start of stack *)
ldr r0, [r11, #-60] (* stacksize *)
cmp r0, #0
beq load_regs (* skip if no stack *)
mov r1, r13 (* this points to the bottom now *)
ldr r2, [r11, #-56] (* stack pointer *)
stack_loop:
ldmia r2!, {r4} (* get stack + update pos *)
stmia r1!, {r4} (* store stack + update pos *)
subs r0, r0, #4
bne stack_loop
load_regs:
(* load general regs *)
ldr r4, [r11, #-44] (* rint *)
ldr r0, [r4]
ldr r1, [r4, #4]
ldr r2, [r4, #8]
ldr r3, [r4, #12]
{$ifdef FPUFPA}
(* load float regs *)
ldr r4, [r11, #-48] (* rfloat *)
ldfd f0, [r4]
ldfd f1, [r4, #8]
ldfd f2, [r4, #16]
ldfd f3, [r4, #24]
{$endif}
(* branch to the proc pointer *)
ldr r4, [r11, #-52]
mov r14, r15
mov r15, r4
(* blx r4 *)
ldr r4, [r11, #-64] (* get resulttype *)
cmp r4, #1
blt int_result
beq int64_result
bgt float_result
int_result:
str r0, [r11, #-72]
b asmcall_end
int64_result:
str r0, [r11, #-72]
str r1, [r11, #-68]
b asmcall_end
float_result:
{$ifdef FPUFPA}
stfd f0, [r11, #-72]
{$else}
b int64_result
{$endif}
b asmcall_end
asmcall_end:
sub r0, r11, #72 (* return pointer to result on stack *)
ldmea r11,{r4,r5,r6,r7,r8,r9,r10,r11,r13,r15}
end;
function TPSExec.InnerfuseCall(_Self, Address: Pointer; CallingConv: TPSCallingConvention; Params: TPSList; res: PPSVariantIFC): Boolean;
var
rint: Trint; { registers r0 to r3 }
rfloat: Trfloat; { registers f0 to f3 }
st: packed array of byte; { stack }
i, j, rindex, findex, stindex: integer;
fvar: PPSVariantIFC;
IsConstructor: Boolean;
{ add a dword to stack }
procedure addstackdword(value: dword);
begin
setlength(st, stindex+4);
pdword(@st[stindex])^ := value;
inc(stindex, 4);
end;
{ add a float to stack }
procedure addstackfloat(value: pointer; size: integer);
begin
setlength(st, stindex + (size * 4));
if size = 1
then psingle(@st[stindex])^ := single(value^)
else pdouble(@st[stindex])^ := double(value^);
inc(stindex, size*4);
end;
{ add to the general registers or overflow to stack }
procedure addgen(value: dword);
begin
if rindex <= 4
then begin
rint[rindex] := value;
inc(rindex);
end
else begin
addstackdword(value);
end;
end;
{ add to the float registers or overflow to stack }
{ size = 1 for single, 2 for double }
procedure addfloat(value: pointer; size: integer);
begin
if findex <= 4
then begin
if size = 1
then rfloat[findex] := single(value^)
else rfloat[findex] := double(value^);
inc(findex);
end
else begin
addstackfloat(value, size);
end;
end;
begin
if (Integer(CallingConv) and 64) <> 0 then begin
IsConstructor := true;
CAllingConv := TPSCallingConvention(Integer(CallingConv) and not 64);
end else IsConstructor := false;
rindex := 1;
findex := 1;
stindex := 0;
setlength(st, stindex);
Result := False;
{ the pointer of the result needs to be passed first in the case of some result types }
if assigned(res)
then begin
case res.atype.basetype of
btStaticArray, btRecord: addgen(dword(res.dta));
end;
end;
{ process all parameters }
for i := 0 to Params.Count-1 do begin
if Params[i] = nil
then Exit;
fvar := Params[i];
{ cook dynamic arrays - fpc stores size-1 at @array-4 }
if (fvar.aType.BaseType = btArray)
then dec(pdword(pointer(fvar.dta^)-4)^);
if fvar.varparam
then begin { var param }
case fvar.aType.BaseType of
{ add var params here }
btArray, btVariant, btSet, btStaticArray, btRecord, btInterface, btClass, {$IFNDEF PS_NOWIDESTRING} btUnicodeString, btWideString, btWideChar, {$ENDIF}
btU8, btS8, btU16, btS16, btU32, btS32, btSingle, btDouble, btExtended, btString, btPChar, btChar, btCurrency
{$IFNDEF PS_NOINT64}, bts64{$ENDIF}: addgen(dword(fvar.dta));
else begin
writeln(stderr, 'Parameter type not recognised!');
Exit;
end;
end; { case }
end else begin { not a var param }
case fvar.aType.BaseType of
// btArray, btVariant, btSet, btStaticArray, btRecord, btInterface, btClass, {$IFNDEF PS_NOWIDESTRING} btWideString, btWideChar, {$ENDIF}
// btU8, btS8, btU16, btS16, btU32, btS32, btSingle, btDouble, btExtended, btString, btPChar, btChar, btCurrency
// {$IFNDEF PS_NOINT64}, bts64{$ENDIF}: writeln('normal param');
{ add normal params here }
btString: addgen(dword(pstring(fvar.dta)^));
btU8, btS8: addgen(dword(pbyte(fvar.dta)^));
btU16, BtS16: addgen(dword(pword(fvar.dta)^));
btU32, btS32: addgen(dword(pdword(fvar.dta)^));
btSingle: {$ifdef FPUFPA}
addfloat(fvar.dta, 1);
{$else}
addgen(dword(psingle(fvar.dta)^));
{$endif}
btDouble{, btExtended}: {$ifdef FPUFPA}
addfloat(fvar.dta, 2);
{$else}
begin
addgen(lo(qword(pdouble(fvar.dta)^)));
addgen(hi(qword(pdouble(fvar.dta)^)));
end;
{$endif}
btPChar: addgen(dword(ppchar(fvar.dta)^));
btChar: addgen(dword(pchar(fvar.dta)^));
{$IFNDEF PS_NOINT64}bts64:{$ENDIF} begin
addgen(dword(pint64(fvar.dta)^ and $ffffffff));
addgen(dword(pint64(fvar.dta)^ shr 32));
end;
btStaticArray: addgen(dword(fvar.dta));
btRecord: for j := 0 to (fvar.atype.realsize div 4)-1 do
addgen(pdword(fvar.dta + j*4)^);
btArray: addstackdword(dword(fvar.dta^)); { this is a bit weird }
{ btVariant, btSet, btInterface, btClass }
else begin
writeln(stderr, 'Parameter type not implemented!');
Exit;
end;
end; { case }
end; { else }
end; { for }
if not assigned(res)
then begin
armasmcall(rint, rfloat, address, st, stindex, rtINT); { ignore return }
end
else begin
case res.atype.basetype of
{ add result types here }
btString: pstring(res.dta)^ := pstring(armasmcall(rint, rfloat, address, st, stindex, rtINT))^;
btU8, btS8: pbyte(res.dta)^ := byte(pdword(armasmcall(rint, rfloat, address, st, stindex, rtINT))^);
btU16, btS16: pword(res.dta)^ := word(pdword(armasmcall(rint, rfloat, address, st, stindex, rtINT))^);
btU32, btS32: pdword(res.dta)^ := pdword(armasmcall(rint, rfloat, address, st, stindex, rtINT))^;
btSingle: psingle(res.dta)^ := pdouble(armasmcall(rint, rfloat, address, st, stindex, rtFLOAT))^;
btDouble{, btExtended}: pdouble(res.dta)^ := pdouble(armasmcall(rint, rfloat, address, st, stindex, rtFLOAT))^;
btPChar: ppchar(res.dta)^ := pchar(pdword(armasmcall(rint, rfloat, address, st, stindex, rtINT))^);
btChar: pchar(res.dta)^ := char(pdword(armasmcall(rint, rfloat, address, st, stindex, rtINT))^);
btStaticArray, btRecord: armasmcall(rint, rfloat, address, st, stindex, rtINT);
btArray: res.dta := armasmcall(rint, rfloat, address, st, stindex, rtINT);
else begin
writeln(stderr, 'Result type not implemented!');
exit;
end; { else }
end; { case }
end;
{ cook dynamic arrays - fpc stores size-1 at @array-4 }
for i := 0 to Params.Count-1 do begin
fvar := Params[i];
if (fvar.aType.BaseType = btArray)
then inc(pdword(pointer(fvar.dta^)-4)^);
end;
Result := True;
end;