static void virtual_init(struct proc *target, struct proc *source)
{
/* Create pml4 */
target->cr3 = page_phys_addr(get_zeroed_page(ZONE_1GB));
/* For now, only map the kernel 512 Gbyte segment */
*((struct pml4e *)VIRT(target->cr3) + pml4_index(KERN_PAGE_OFFSET)) =
*((struct pml4e *)VIRT(source->cr3) + pml4_index(KERN_PAGE_OFFSET));
}
/**
* Called when a pagefault occurs, is in charge of fixing the fault and swapping
* if necessary.
*/
void cPageFault(isrVal_t registers)
{
addr_t page = getCR2();
addr_t page_addr = page & ~(0xFFF);
#ifdef PAGEDBG
printf("PG!\n");
printf("Fault addr: %X\nPage index: %X\n", page, page_addr);
printf("Fault type: %X\n", registers.errCode);
printf("EIP: %X\nESP: %X\nESP: %X\n",
registers.eip, registers.procesp, registers.esp);
printf("eax: %X\tebx: %X\necx: %X\tedx: %X\n",
registers.eax, registers.ebx, registers.ecx, registers.edx);
#endif
if (registers.cs != 0x8 && registers.cs != 0x18)
panic("Incorrect frame!");
if (USER(registers.errCode))
panic("Userspace isn't implemented yet!");
if (RESERVED(registers.errCode))
panic("A reserved bit has been set!\n");
if (PRESENT(registers.errCode))
panic("Illegal operation!");
addr_t pd = getPageDir();
/**
* The data bit only works if a specific bit is set. See intel docs volume 3
* for more information.
*/
if (DATA(registers.errCode))
{
#ifdef PAGEDBG
printf("Trying to access unimplemented data!\n");
#endif
if (WRITE(registers.errCode))
{
#ifdef PAGEDBG
printf("Faulted a write attempt!\n");
printf("Adding page!\n");
#endif
if (USER(registers.errCode))
{
//Add a user page!
}
else
{
#ifdef PAGEDBG
printf("Adding a kernel page!\n");
#endif
if (idx_kernel_space == MAP_NOMAP)
panic("Kernel page map not correctly initialised!");
int ret = page_alloc_page
(idx_kernel_space, page_addr, (void*)pd, FALSE);
if (ret != -E_SUCCESS)
{
printf("ERRCODE: %X\n", -ret);
panic("Couldn't alloc page!");
}
#ifdef PAGEDBG
printf("Phys of %X = %X\n", page, page_phys_addr(page, (void*)pd));
#endif
}
}
else
{
#ifdef PAGEDBG
printf("Faulted a read attempt!\n");
#endif
// Assume the page may be read!
if (idx_kernel_space == MAP_NOMAP)
panic("Kernel page map not correctly initialised!");
int ret = page_alloc_page(idx_kernel_space, page_addr,
(void*)pd, FALSE);
if (ret != -E_SUCCESS)
{
printf("ERRCODE: %X\n", -ret);
panic("Couldn't alloc page!");
}
#ifdef PAGEDBG
printf("Phys of %X = %X\n", page, page_phys_addr(page, (void*)pd));
#endif
}
}
else
{
#ifdef PAGEDBG
panic("Trying to run unimplemented code!\n");
#endif
}
#ifdef UNDEFINED
printf("Page faults currently under construction!\n");
#endif
}