/**************************************************************************************
Copyright (c) 2002
The UbixOS Project
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$Id: paging.c,v 1.24 2003/04/24 00:16:30 reddawg Exp $
**************************************************************************************/
#include <vmm/paging.h>
#include <vmm/memory.h>
#include <sys/idt.h>
#include <sys/gdt.h>
#include <ubixos/types.h>
#include <ubixos/schedule.h>
#include <ubixos/panic.h>
#include <lib/kmalloc.h>
uLong *pageDirectory = 0x0;
uLong memoryStart = 0x100000;
uLong *kernelPageDirectory = 0x0;
/************************************************************************
Function: void initPageSystem()
Description: This Function Will Initialize The Ubix Paging Sytem
Notes:
07/29/02 - I Started The Rewrite Of This Function Hopefully All Goes Well
This Is The Startup Routine To Build The Initial VM Space.
Also Note I May Switch The Page Fault To A Task Gate.
07/30/02 - I Decided That To Save On Performance All Page Tables Will Be
Mapped In At BFC00000 So That Memory Does Not Need To Be Relocated
To Alter Page Tables.
Also Put Page Index At 0x100000
************************************************************************/
void initPagingSystem() {
int i=0,x=0;
uLong *pageTable;
struct tssStruct *doubleFaultTSS = (struct tssStruct *)0x4000;
//Allocate A Page For The Kernels VM Space Page Directory
kernelPageDirectory = (uLong *)findFreePage(_current->id);
//Make Sure The Page Directory Is Clean
for (i=0;i<pageEntries;i++) {
kernelPageDirectory[i] = (uLong)0x0;
}
//Allocate A Page For The First 4MB Of Memory
pageTable = (uLong *)findFreePage(_current->id);
kernelPageDirectory[0] = (uLong)((uLong)(pageTable) | pagePresent|pageWrite|pageUser);//pageDefault);
//Make Sure The Page Table Is Clean
for (i=0;i<pageEntries;i++) {
pageTable[i] = (uLong)0x0;
}
//Map The First 1MB Of Memory To The Kernel VM Space
for (i=0;i<(pageEntries/4);i++) {
if ((i*0x1000) < 0xC0000) {
pageTable[i] = (uLong)((i*0x1000) | pagePresent|pageWrite|pageUser);// pageDefault);
}
else {
pageTable[i] = (uLong)((i*0x1000) | pagePresent|pageUser);// pageDefault);
}
}
//Create Page Tables For The Top 1GB Of VM Space This Is To Be Shared With All VM Spaces
for (i=768;i<pageEntries;i++) {
pageTable = (uLong *)findFreePage(-1);
//Make Sure The Page Table Is Clean
for (x=0;x<pageEntries;x++) {
pageTable[x] = (uLong)0x0;
}
//Map In The Page Directory
kernelPageDirectory[i] = (uLong)((uLong)(pageTable) | pagePresent|pageWrite|pageUser);//pageDefault);
}
//Set Up Memory To Be All The Allocated Page Directories
pageTable = (uLong *)findFreePage(-1);
kernelPageDirectory[767] = ((uLong)pageTable | pagePresent|pageWrite|pageUser);//pageDefault);
for (i=0;i<pageEntries;i++) {
pageTable[i] = kernelPageDirectory[i];
}
//Also Set Up Page Directory To Be The The First Page In 0xE0400000
pageTable = (uLong *)(kernelPageDirectory[0] & 0xFFFFF000);
pageTable[256] = (uLong)((uLong)(kernelPageDirectory) | pagePresent|pageWrite|pageUser);//pageDefault);
//Now Lets Turn On Paging With This Initial Page Table
asm(
"movl %0,%%eax \n"
"movl %%eax,%%cr3 \n"
"movl %%cr0,%%eax \n"
"orl $0x80010000,%%eax \n" //Flags To Enable Paging With Protection
"movl %%eax,%%cr0 \n"
: : "d" ((uLong *)(kernelPageDirectory))
);
//Now Add The IDT Entry For Page Faults
setVector(_pageFault,14,dPresent + dInt + dDpl3);
//Remap The Memory List
for (i=0x101000;i<=(0x101000+(numPages*sizeof(mMap)));i+=0x1000) {
remapPage(i,(0xE6667000+(i-0x101000)));
}
memoryMap = (mMap *)0xE6667000;
doubleFaultTSS->back_link = 0x0;
doubleFaultTSS->esp0 = (uInt32)kmalloc(4096,-2)+4095;
doubleFaultTSS->ss0 = 0x10;
doubleFaultTSS->esp1 = 0x0;
doubleFaultTSS->ss1 = 0x0;
doubleFaultTSS->esp2 = 0x0;
doubleFaultTSS->ss2 = 0x0;
doubleFaultTSS->cr3 = (unsigned int)kernelPageDirectory;
doubleFaultTSS->eip = (unsigned int)&doubleFault;
doubleFaultTSS->eflags = 0x206;
doubleFaultTSS->esp = 0x1BFFF;
doubleFaultTSS->ebp = 0x1BFFF;
doubleFaultTSS->esi = 0x0;
doubleFaultTSS->edi = 0x0;
doubleFaultTSS->es = 0x10;
doubleFaultTSS->cs = 0x08;
doubleFaultTSS->ss = 0x10;
doubleFaultTSS->ds = 0x10;
doubleFaultTSS->fs = 0x10;
doubleFaultTSS->gs = 0x10;
doubleFaultTSS->ldt = 0x0;
doubleFaultTSS->trace_bitmap = 0x0000;
doubleFaultTSS->io_map = 0x8000;
}
void *mapFromTask(pidType pid,void *ptr,uInt32 size) {
kTask_t *child = 0x0;
uLong i = 0x0,x = 0x0,y = 0x0,count = ((size+4095)/0x1000),c = 0x0;
uShort dI = 0x0,tI = 0x0;
uInt32 baseAddr = 0x0,offset = 0x0;
uInt32 *childPageDir = (uInt32 *)0x5A00000;
uInt32 *childPageTable = 0x0;
uInt32 *pageTableSrc = 0x0;
offset = (uInt32)ptr & 0xFFF;
baseAddr = (uInt32)ptr & 0xFFFFF000;
child = getTask(pid);
//Calculate The Page Table Index And Page Directory Index
dI = (baseAddr/(1024*4096));
tI = ((baseAddr-(dI*(1024*4096)))/4096);
remapPage(child->tss.cr3,0x5A00000);
for (i=0;i<0x1000;i++) {
remapPage(childPageDir[i],0x5A01000 + (i * 0x1000));
}
for (x=(_current->oInfo.vmStart/(1024*4096));x<1024;x++) {
pageTableSrc = (uInt32 *)(tablesBaseAddress + (4096*x));
for (y=0;y<1024;y++) {
//Loop Through The Page Table Find An UnAllocated Page
if ((uInt32)pageTableSrc[y] == (uInt32)0x0) {
if (count > 1) {
for (c=0;((c<count) && (y+c < 1024));c++) {
if ((uInt32)pageTableSrc[y+c] != (uInt32)0x0) {
c = -1;
break;
}
}
if (c != -1) {
for (c=0;c<count;c++) {
if ((tI + c) >= 0x1000) {
dI++;
tI = 0-c;
}
childPageTable = (uInt32 *)(0x5A01000 + (0x1000 * dI));
remapPage(childPageTable[tI+c],((x*(1024*4096))+((y+c)*4096)));
}
unmapPage(0x5A00000,1);
for (i=0;i<0x1000;i++) {
unmapPage((0x5A01000 + (i*0x1000)),1);
}
return((void *)((x*(1024*4096))+(y*4096)+offset));
}
}
else {
//Map A Physical Page To The Virtual Page
childPageTable = (uInt32 *)(0x5A01000 + (0x1000 * dI));
remapPage(childPageTable[tI],((x*(1024*4096))+(y*4096)));
//Return The Address Of The Mapped In Memory
unmapPage(0x5A00000,1);
for (i=0;i<0x1000;i++) {
unmapPage((0x5A01000 + (i*0x1000)),1);
}
return((void *)((x*(1024*4096))+(y*4096)+offset));
}
}
}
}
return(0x0);
}
void unmapPages(void *ptr,uInt32 size) {
uInt32 baseAddr = (uInt32)ptr & 0xFFFFF000;
uInt32 dI = 0x0,tI = 0x0;
uInt32 y = 0x0;
uInt32 *pageTable = 0x0;
dI = (baseAddr/(1024*4096));
tI = ((baseAddr-(dI*(1024*4096)))/4096);
pageTable = (uInt32 *)(tablesBaseAddress + (4096*dI));
for (y=tI;y<(tI+((size+4095)/4096));y++) {
pageTable[y] = 0x0;
}
return;
}
