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git-svn-id: https://spexeah.com:8443/svn/Asuro@18 6dbc8c32-bb84-406f-8558-d1cf31a0ab0c
This commit is contained in:
kieron
2017-05-15 19:52:31 +00:00
parent e33d8ad9eb
commit eebe77ad9b
19 changed files with 36 additions and 31 deletions
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67
src/gdt.pas
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@ -13,10 +13,11 @@ type
limit_n_flags : Byte;
base_high : Byte;
end;
PSegmentDescriptor = ^TSegmentDescriptor;
var
GDTarr : array[0..3] of TSegementDescriptor;
GDTptr : ^TSegementDescriptor;
GDTarr : array of TSegementDescriptor;
GDTptr : PSegmentDescriptor;
GDT_length : integer = 0;
procedure init();
@ -46,48 +47,52 @@ end;
procedure create(base : dword; limit : dword; flags : byte);
var
descriptor : array[0..8] of Byte;
descriptor_ptr : ^Byte = @descriptor[0];
s_descriptor : TSegementDescriptor;
descriptor : array[0..8] of Byte;
descriptor_ptr : ^Byte = @descriptor[0];
s_descriptor : TSegementDescriptor;
s_descriptor_ptr : ^TSegementDescriptor = @s_descriptor;
begin
if limit <= 65536 then
descriptor[6] := $40
else
if (limit and $FFF) <> $FFF then
limit := (limit >> 12) -1
else
limit := limit >> 12;
descriptor[6] := $C0;
if limit <= 65536 then begin
descriptor[6] := $40
end else begin
if (limit and $FFF) <> $FFF then begin
limit := (limit SHR 12) -1
end else begin
limit := limit SHR 12;
end;
end;
descriptor[6] := $C0;
descriptor[0] := limit and $FF;
descriptor[1] := (limit shr 8) and $FF;
descriptor[6] := limit or ((limit shr 16) and $F);
descriptor[0] := limit and $FF;
descriptor[1] := (limit shr 8) and $FF;
descriptor[6] := limit or ((limit shr 16) and $F);
descriptor[2] := base and $FF;
descriptor[3] := (base shr 8) and $FF;
descriptor[4] := (base shr 16) and $FF;
descriptor[7] := (base shr 24) and $FF;
descriptor[2] := base and $FF;
descriptor[3] := (base shr 8) and $FF;
descriptor[4] := (base shr 16) and $FF;
descriptor[7] := (base shr 24) and $FF;
descriptor[5] := flags;
descriptor[5] := flags;
asm
MOV EAX, descriptor_ptr
MOV s_descriptor_ptr, EAX
end;
asm
MOV EAX, descriptor_ptr
MOV s_descriptor_ptr, EAX
end;
descriptor_ptr = @descriptor[4];
descriptor_ptr = @descriptor[4];
asm
asm
MOV EAX, descriptor_ptr
MOV EBX, s_descriptor_ptr
ADD EBX, 1
MOV (EBX), EAX
end;
end;
GDTarr[GDT_length] := s_descriptor;
GDT_length := GDT_length + 1;
GDTarr[GDT_length] := s_descriptor;
GDT_length := GDT_length + 1;
end;
end.
end.