Files
TempleOS-Rijn/Kernel/Mem/PageTables.HC
T
2018-09-08 21:47:50 +02:00

155 lines
3.3 KiB
HolyC

asm {
// $LK,"::/Doc/MemOverview.DD"$
USE32
SYS_INIT_PAGE_TABLES::
//Set page tables to identity map everything.
MOV EDI,SYS_FIXED_AREA
XOR EAX,EAX
MOV ECX,sizeof(CSysFixedArea)/4
REP_STOSD //Init entire SYS_FIXED_AREA to zero
MOV EAX,0x80000001
CPUID
BT EDX,26
JC @@15
MOV U8 [SYS_GIG_PAGES],FALSE
//PML2: Use 2Meg PAges
MOV EAX,0x87 //bit 7 is page size (2Meg)
XOR EDX,EDX
MOV EDI,SYS_FIXED_AREA+CSysFixedArea.pml2
MOV ECX,MEM_NUM_2MEG
@@05: MOV U32 [EDI],EAX
ADD EDI,4
MOV U32 [EDI],EDX
ADD EDI,4
ADD EAX,0x200000
ADC EDX,0
LOOP @@05
//PML3: Use 2Meg Pages
MOV EAX,SYS_FIXED_AREA+CSysFixedArea.pml2+7
XOR EDX,EDX
MOV EDI,SYS_FIXED_AREA+CSysFixedArea.pml3
MOV ECX,MEM_NUM_USED_1GIG
@@10: MOV U32 [EDI],EAX
ADD EDI,4
MOV U32 [EDI],EDX
ADD EDI,4
ADD EAX,0x1000
ADC EDX,0
LOOP @@10
JMP @@25
@@15: MOV U8 [SYS_GIG_PAGES],TRUE
//PML3: Use 1Gig Pages
MOV EAX,0x87 //bit 7 is page size (1Gig)
XOR EDX,EDX
MOV EDI,SYS_FIXED_AREA+CSysFixedArea.pml3
MOV ECX,MEM_NUM_USED_1GIG
@@20: MOV U32 [EDI],EAX
ADD EDI,4
MOV U32 [EDI],EDX
ADD EDI,4
ADD EAX,0x40000000
ADC EDX,0
LOOP @@20
//PML4
@@25: MOV EAX,SYS_FIXED_AREA+CSysFixedArea.pml3+7
XOR EDX,EDX
MOV EDI,SYS_FIXED_AREA+CSysFixedArea.pml4
MOV ECX,MEM_NUM_1GIG/(0x1000/8)
@@30: MOV U32 [EDI],EAX
ADD EDI,4
MOV U32 [EDI],EDX
ADD EDI,4
ADD EAX,0x1000
ADC EDX,0
LOOP @@30
MOV U32 [SYS_CODE_BP],SYS_FIXED_AREA+CSysFixedArea.adam_bp
MOV U32 [SYS_CODE_BP+4],0
MOV U32 [SYS_DATA_BP],0
MOV U32 [SYS_DATA_BP+4],0
XOR EAX,EAX
MOV AX,U16 [SYS_MEM_E801] //1 Kb blks between 1M and 16M
SHL EAX,10
ADD EAX,0x100000
MOV EBX,U32 [SYS_HEAP_BASE] //SYS_FIXED_AREA+sizeof(CSysFixedArea)
SUB EAX,EBX
/*$AN,"ExpandHeap",A="ExpandHeap"$
TempleOS initializes the heap to the val
of the BIOS E801 lowest 16Meg val. It
later adds the rest to the heap. There
are a few allocations which occur while
it is set to this small val.
At some point, it might be nice to
initialize to the full val but it is a
pain without MAlloc up-and-running.
*/
#define CONSERVATIVE_16MEG_SIZE 0xF00000
#define ESTIMATED_MISC_ALLOCS 0x100000
#assert CONSERVATIVE_16MEG_SIZE-
(SYS_FIXED_AREA+sizeof(CSysFixedArea))>MEM_ADAM_STK+
ESTIMATED_MISC_ALLOCS
//EBX=BASE EAX=SIZE
TEST U8 [SYS_MEM_INIT_FLAG],1
JZ @@35
PUSH EAX
MOV EDI,EBX
MOV ECX,EAX
MOV AL,U8 [SYS_MEM_INIT_VAL]
REP_STOSB
POP EAX
@@35: SHR EAX,MEM_PAGE_BITS
MOV ESI,SYS_FIXED_AREA+CSysFixedArea.adam_bp
MOV EDI,U32 CBlkPool.mem_free_lst[ESI]
MOV U32 CMemBlk.next[EBX],EDI
MOV U32 CMemBlk.next+4[EBX],0
MOV U32 CBlkPool.mem_free_lst[ESI],EBX
MOV U32 CBlkPool.mem_free_lst+4[ESI],0
MOV U32 CMemBlk.mb_signature[EBX],MBS_UNUSED_SIGNATURE_VAL
MOV U32 CMemBlk.pages[EBX],EAX
SHL EAX,MEM_PAGE_BITS
ADD U32 CBlkPool.alloced_u8s[ESI],EAX
RET
}
I64 *MemPageTable(U8 *a)
{//Point to page table entry for addr.
if (sys_gig_pages)
return SYS_FIXED_AREA+offset(CSysFixedArea.pml3)+a>>30*8;
else
return SYS_FIXED_AREA+offset(CSysFixedArea.pml2)+a>>21*8;
}
I64 MemPageSize(U8 *)
{//Page table entry size for addr.
if (sys_gig_pages)
return 1<<30; //1Gig
else
return 1<<21; //2Meg
}
Bool MemPagePresentMark(U8 *a,Bool val)
{//Mark an addr's page present or not-present.
I64 *pte=MemPageTable(a);
Bool res=*pte&1;
if (val)
*pte=*pte|1; //Mark present
else
*pte=*pte&~1; //Mark not present
InvlPg(a);
return res;
}