diff options
Diffstat (limited to 'src/core')
| -rw-r--r-- | src/core/paging.c | 98 | ||||
| -rw-r--r-- | src/core/paging.h | 17 | ||||
| -rw-r--r-- | src/core/scheduler.c | 0 | ||||
| -rw-r--r-- | src/core/scheduler.h | 5 |
4 files changed, 108 insertions, 12 deletions
diff --git a/src/core/paging.c b/src/core/paging.c index b1f462f..c32a3bc 100644 --- a/src/core/paging.c +++ b/src/core/paging.c @@ -1,21 +1,43 @@ #include "paging.h" +#include "libc/stdio.h" + +/// Use a bitmap to keep track of allocated pages +char pages_status[PAGING_MAX_PAGES/8]; +/// Kernel page directory (ATTENTION need to be 4096) +u32 k_pd[PAGING_MAX_DIR_ENTRY] __attribute__((aligned(4096))); +/// Kernel page table +u32 k_pt[PAGING_MAX_DIR_ENTRY][1024] __attribute__((aligned(4096))); void paging_enable(){ - int *page_dir=(int*)PAGING_DIR_LOCATION; - int *page_table=(int*)PAGING_TABLE_LOCATION; + // Init pages status + for(int i=0;i<PAGING_MAX_PAGES/8;i++) + pages_status[i]=0; // Init page directory - for(int i=0;i<1024;i++) - page_dir[i]=0; - page_dir[0]=(int)page_table; - page_dir[0] |=7; // Permissions + for(int i=0;i<PAGING_MAX_DIR_ENTRY;i++){ + k_pd[i]=0; + } + k_pd[0]=((int)&k_pt[0][0]); + k_pd[0]|=7; // Permissions // Init page table 0 int addr_offset=0; for(int i=0;i<1024;i++){ - page_table[i]=addr_offset; - page_table[i]|=7; // Permission - addr_offset+=4096; // 4Ko pages + k_pt[0][i]=addr_offset; + k_pt[0][i]|=7; // Permission + paging_set_usage(addr_offset,1); // Mark addr as used + addr_offset+=PAGING_PAGE_SIZE; // 4Ko pages + } + + // Allow access to more ram + for(int i=1;i<PAGING_MAX_DIR_ENTRY;i++){ + k_pd[i]=((int)&k_pt[i][0]); + k_pd[i]|=7; // Permissions + for(int j=0;j<1024;j++){ + k_pt[i][j]=addr_offset; + k_pt[i][j]|=7; // Permission + addr_offset+=PAGING_PAGE_SIZE; // 4Ko pages + } } // Turns on paging @@ -25,7 +47,63 @@ void paging_enable(){ "movl %%cr0, %%eax \n\t" "orl %1, %%eax \n\t" "movl %%eax, %%cr0 \n\t" // Turn on paging - :: "i" (PAGING_DIR_LOCATION), "i" (PAGING_CR0_BIT) + :: "b" (k_pd), "i" (PAGING_CR0_BIT) ); +} +void paging_set_usage(int addr,char state){ + char bytes=pages_status[addr/PAGING_PAGE_SIZE/8]; + char bit=addr/PAGING_PAGE_SIZE%8; + if(state=0) + pages_status[addr/PAGING_PAGE_SIZE/8]=~(1<<bit)&bytes; + else + pages_status[addr/PAGING_PAGE_SIZE/8]=(1<<bit)|bytes; +} + +void paging_dump(int min,int max){ + for(int i=0;i<(PAGING_MAX_PAGES/8);i++){ + for(int j=0;j<8;j++){ + char status=(pages_status[i]>>j)&0x1; + if((i*8+j)>=min){ + if((i*8+j)<max || max<0) + printi(status); + } + } + } +} + +char* paging_allocate_next_page(){ + for(int i=0;i<(PAGING_MAX_PAGES/8);i++){ + char bytes=pages_status[i]; + for(int j=0;j<8;j++){ + char state=(bytes>>j)&1; + if(state!=1){ + int page_id=i*8+j; + int page_addr=PAGING_PAGE_SIZE*page_id; + paging_set_usage(page_addr,1); + return((char*)page_addr); + } + } + } + print("Could not allocate anymore pages! Stopping..."); + asm("hlt"); +} + +char *paging_allocate(int p){ + int *page_dir=(int*)paging_allocate_next_page(); + int *page_table; + int current_page_entry=0; + int current_dir_entry=0; + while(current_page_entry<p){ + if(current_page_entry%1024 == 0){ + current_dir_entry++; + page_table=(int*)paging_allocate_next_page(); + page_dir[current_dir_entry]=(int)page_table; + } + int entry=current_page_entry%1024; + page_table[current_page_entry]=(int)paging_allocate_next_page(); + current_page_entry++; + print("Jean\n"); + } + print("end"); }
\ No newline at end of file diff --git a/src/core/paging.h b/src/core/paging.h index 1e8f4e3..ad3671e 100644 --- a/src/core/paging.h +++ b/src/core/paging.h @@ -2,12 +2,25 @@ #define PAGING_H #define PAGING_CR0_BIT 0x80000000 -#define PAGING_DIR_LOCATION 0x1000 -#define PAGING_TABLE_LOCATION 0x5000 +#define PAGING_PAGE_SIZE 4096 +#define PAGING_MAX_PAGES 2048 +#if PAGING_MAX_PAGES%1024>0 + #define PAGING_MAX_DIR_ENTRY PAGING_MAX_PAGES/1024+1 +#else + #define PAGING_MAX_DIR_ENTRY PAGING_MAX_PAGES/1024 +#endif /* * Configure and enable paging */ void paging_enable(); +char* paging_allocate_next_page(); +void paging_set_usage(int addr,char state); +/** + * Create a new page directory containing + * p pages. + */ +char *paging_allocate(int p); +void paging_dump(int min,int max); #endif
\ No newline at end of file diff --git a/src/core/scheduler.c b/src/core/scheduler.c new file mode 100644 index 0000000..e69de29 --- /dev/null +++ b/src/core/scheduler.c diff --git a/src/core/scheduler.h b/src/core/scheduler.h new file mode 100644 index 0000000..f15168b --- /dev/null +++ b/src/core/scheduler.h @@ -0,0 +1,5 @@ +#ifndef SCHEDULER_H +#define SCHEDULER_H + + +#endif
\ No newline at end of file |