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#include "kernel.h"
enum PAGE_PTE_FLAGS {
I86_PTE_PRESENT = 1, //0000000000000000000000000000001
I86_PTE_WRITABLE = 2, //0000000000000000000000000000010
I86_PTE_USER = 4, //0000000000000000000000000000100
I86_PTE_WRITETHOUGH = 8, //0000000000000000000000000001000
I86_PTE_NOT_CACHEABLE = 0x10, //0000000000000000000000000010000
I86_PTE_ACCESSED = 0x20, //0000000000000000000000000100000
I86_PTE_DIRTY = 0x40, //0000000000000000000000001000000
I86_PTE_PAT = 0x80, //0000000000000000000000010000000
I86_PTE_CPU_GLOBAL = 0x100, //0000000000000000000000100000000
I86_PTE_LV4_GLOBAL = 0x200, //0000000000000000000001000000000
I86_PTE_FRAME = 0x7FFFF000 //1111111111111111111000000000000
};
enum PAGE_PDE_FLAGS {
I86_PDE_PRESENT = 1, //0000000000000000000000000000001
I86_PDE_WRITABLE = 2, //0000000000000000000000000000010
I86_PDE_USER = 4, //0000000000000000000000000000100
I86_PDE_PWT = 8, //0000000000000000000000000001000
I86_PDE_PCD = 0x10, //0000000000000000000000000010000
I86_PDE_ACCESSED = 0x20, //0000000000000000000000000100000
I86_PDE_DIRTY = 0x40, //0000000000000000000000001000000
I86_PDE_4MB = 0x80, //0000000000000000000000010000000
I86_PDE_CPU_GLOBAL = 0x100, //0000000000000000000000100000000
I86_PDE_LV4_GLOBAL = 0x200, //0000000000000000000001000000000
I86_PDE_FRAME = 0x7FFFF000 //1111111111111111111000000000000
};
//! page table entry
typedef uint32_t pt_entry;
//! a page directery entry
typedef uint32_t pd_entry;
////
//! virtual address
typedef uint32_t virtual_addr;
typedef uint32_t physical_addr;
typedef uint8_t bool;
//! i86 architecture defines 1024 entries per table--do not change
#define PAGES_PER_TABLE 1024
#define PAGES_PER_DIR 1024
#define PAGE_DIRECTORY_INDEX(x) (((x) >> 22) & 0x3ff)
#define PAGE_TABLE_INDEX(x) (((x) >> 12) & 0x3ff)
#define PAGE_GET_PHYSICAL_ADDRESS(x) (*x & ~0xfff)
//! page table represents 4mb address space
#define PTABLE_ADDR_SPACE_SIZE 0x400000
//! directory table represents 4gb address space
#define DTABLE_ADDR_SPACE_SIZE 0x100000000
//! page sizes are 4k
#define PAGE_SIZE 4096
//! page table
struct ptable {
pt_entry m_entries[PAGES_PER_TABLE];
};
//! page directory
struct pdirectory {
pd_entry m_entries[PAGES_PER_DIR];
};
void pt_entry_add_attrib (pt_entry* e, uint32_t attrib)
{
}
void pt_entry_del_attrib (pt_entry* e, uint32_t attrib)
{
}
void pt_entry_set_frame (pt_entry* e , physical_addr addr)
{
}
bool pt_entry_is_present (pt_entry e)
{
return 1;
}
bool pt_entry_is_writable (pt_entry e)
{
return 1;
}
physical_addr pt_entry_pfn (pt_entry e)
{
return 1;
}
void pd_entry_add_attrib (pd_entry* e, uint32_t attrib)
{
}
void pd_entry_del_attrib (pd_entry* e, uint32_t attrib)
{
}
void pd_entry_set_frame (pd_entry* e, physical_addr add)
{
}
bool pd_entry_is_present (pd_entry e)
{
return 1;
}
bool pd_entry_is_user (pd_entry e)
{
return 1;
}
bool pd_entry_is_4mb (pd_entry e)
{
return 1;
}
bool pd_entry_is_writable (pd_entry e)
{
return 1;
}
physical_addr pd_entry_pfn (pd_entry e)
{
return 1;
}
void pd_entry_enable_global (pd_entry e)
{
}
uint8_t vmmngr_alloc_page (pt_entry* e)
{
//! allocate a free physical frame
void* p = pmmngr_alloc_block ();
if (!p)
return 0;
//! map it to the page
pt_entry_set_frame (e, (physical_addr)p);
pt_entry_add_attrib (e, I86_PTE_PRESENT);
return 1;
}
void vmem_init()
{
}
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