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Debug paging

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This commit is contained in:
Loic Guegan 2021-04-17 16:31:45 +02:00
parent 1e397041c2
commit dcadede2d4
3 changed files with 14 additions and 22 deletions
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6
src/bringelle.c
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@ -8,7 +8,7 @@
extern void interrupt_enable(); extern void interrupt_enable();
void utask(){ void utask(){
char *msg=(char*)4206592+300; char *msg=(char*)PAGING_ENTRY_POINT_VIRT+300;
msg[0]='A'; msg[0]='A';
msg[1]='\0'; msg[1]='\0';
while(1){ while(1){
@ -20,7 +20,7 @@ void utask(){
} }
void utask2(){ void utask2(){
char *msg=(char*)4206592+300; char *msg=(char*)PAGING_ENTRY_POINT_VIRT+300;
msg[0]='B'; msg[0]='B';
msg[1]='\0'; msg[1]='\0';
while(1){ while(1){
@ -53,8 +53,6 @@ void bringelle(){
int* page_dir=paging_allocate(2); int* page_dir=paging_allocate(2);
task_create(page_dir, utask,100, 0xFF); task_create(page_dir, utask,100, 0xFF);
int* page_dir2=paging_allocate(2); int* page_dir2=paging_allocate(2);
task_create(page_dir2, utask2,100,0xFF); task_create(page_dir2, utask2,100,0xFF);

26
src/core/paging.c
View file

@ -89,42 +89,36 @@ char* paging_allocate_next_page(){
asm("hlt"); asm("hlt");
} }
// TODO: Take p into account
int *paging_allocate(int p){ int *paging_allocate(int p){
// ----- Allow kernel access during interruption // ----- Populate kernel adresses (to be able to execute interrupts codes)
int *page_dir=(int*)paging_allocate_next_page(); int *page_dir=(int*)paging_allocate_next_page();
int *k_page_table=(int*)paging_allocate_next_page(); int *k_page_table=(int*)paging_allocate_next_page();
// Init page directory // Kernel is located in the first 4Mb (page dir entry 0)
page_dir[0]=(int)k_page_table|3; page_dir[0]=(int)k_page_table|3;
// Init page table 0
int addr_offset=0; int addr_offset=0;
for(int i=0;i<1024;i++){ for(int i=0;i<1024;i++){
k_page_table[i]=addr_offset; k_page_table[i]=addr_offset;
k_page_table[i]|=3; // Permission k_page_table[i]|=3; // Permissions
addr_offset+=PAGING_PAGE_SIZE; // 4Ko pages addr_offset+=PAGING_PAGE_SIZE; // 4Ko pages
} }
// ----- Task table // ----- Populate task adresses
int *u_page_table=(int*)paging_allocate_next_page(); int *u_page_table=(int)paging_allocate_next_page();
page_dir[1]=(int)u_page_table|7; page_dir[1]=(int)u_page_table|7;
u_page_table[0]=(int)page_dir|7; // Virtual address is 1024*4096/4 int dir_entry=1; // Entry point is at 1024*4096=4194304 (page dir entry 1 and page table entry 0)
u_page_table[1]=(int)k_page_table|7; int pt_entry=0;
u_page_table[2]=(int)u_page_table|7;
int dir_entry=1;
int pt_entry=3;
int p_current=max(1,p); // Allocate at least 1 page int p_current=max(1,p); // Allocate at least 1 page
while(p_current!=0){ while(p_current!=0){
u_page_table[pt_entry]=(int)paging_allocate_next_page()|7;
p_current--;
pt_entry++;
if(pt_entry%1024==0){ if(pt_entry%1024==0){
dir_entry++; dir_entry++;
pt_entry=0; pt_entry=0;
u_page_table=(int*)paging_allocate_next_page(); u_page_table=(int*)paging_allocate_next_page();
page_dir[dir_entry]=(int)u_page_table|7; page_dir[dir_entry]=(int)u_page_table|7;
} }
u_page_table[pt_entry]=(int)paging_allocate_next_page()|7;
p_current--;
} }
return page_dir; return page_dir;
} }

4
src/core/paging.h
View file

@ -10,8 +10,8 @@
#define PAGING_MAX_DIR_ENTRY PAGING_MAX_PAGES/1024 #define PAGING_MAX_DIR_ENTRY PAGING_MAX_PAGES/1024
#endif #endif
#define PAGING_PADDR(entry) ((int*)(((u32)entry)&0xFFFFF000)) #define PAGING_PADDR(entry) ((int*)(((u32)entry)&0xFFFFF000))
#define PAGING_ENTRY_POINT_VIRT (1024*PAGING_PAGE_SIZE+3*PAGING_PAGE_SIZE) #define PAGING_ENTRY_POINT_VIRT (1024*PAGING_PAGE_SIZE)
#define PAGING_ENTRY_POINT_PHY(page_dir) ((int*)(((int*)((((int*)page_dir)[1])&0xFFFFF000))[3]&0xFFFFF000)) #define PAGING_ENTRY_POINT_PHY(page_dir) ((int*)(((int*)((((int*)page_dir)[1])&0xFFFFF000))[0]&0xFFFFF000))
/** /**
* Configure and enable paging * Configure and enable paging