static uint16
alloc_idle_TSS (int cpu_num)
{
int i;
descriptor *ad = (descriptor *)KERN_GDT;
quest_tss *pTSS = (quest_tss *) (&idleTSS[cpu_num]);
void idle_task (void);
/* Search 2KB GDT for first free entry */
for (i = 1; i < 256; i++)
if (!(ad[i].fPresent))
break;
if (i == 256)
panic ("No free selector for TSS");
ad[i].uLimit0 = sizeof (idleTSS[cpu_num]) - 1;
ad[i].uLimit1 = 0;
ad[i].pBase0 = (u32) pTSS & 0xFFFF;
ad[i].pBase1 = ((u32) pTSS >> 16) & 0xFF;
ad[i].pBase2 = (u32) pTSS >> 24;
ad[i].uType = 0x09; /* 32-bit tss */
ad[i].uDPL = 0; /* Only let kernel perform task-switching */
ad[i].fPresent = 1;
ad[i].f0 = 0;
ad[i].fX = 0;
ad[i].fGranularity = 0; /* Set granularity of tss in bytes */
u32 *stk = map_virtual_page (alloc_phys_frame () | 3);
pTSS->CR3 = (u32) get_pdbr ();
pTSS->initial_EIP = (u32) & idle_task;
stk[1023] = pTSS->initial_EIP;
pTSS->EFLAGS = F_1 | F_IOPL0;
pTSS->ESP = (u32) &stk[1023];
pTSS->EBP = pTSS->ESP;
/* Return the index into the GDT for the segment */
return i << 3;
}
/**
* Prints memory info
*/
void print_meminfo() {
printk("Total mem: %d MB\nFree mem: %d MB\n", get_mem_size() / 1024, (get_max_blocks() - get_used_blocks()) * 4 / 1024);
printk("Heap size: %d KB Free heap: %d KB\n", get_heap_size() / 1024, (get_heap_size() - get_used_heap()) / 1024);
printk("cr0: %x cr2: %x cr3: %x\n", get_cr0(), get_cr2(), get_pdbr());
}
/* Create an address space for boot modules */
static uint16
load_module (multiboot_module * pmm, int mod_num)
{
uint32 *plPageDirectory = get_phys_addr (pg_dir[mod_num]);
uint32 *plPageTable = get_phys_addr (pg_table[mod_num]);
void *pStack = get_phys_addr (ul_stack[mod_num]);
/* temporarily map pmm->pe in order to read pph->p_memsz */
Elf32_Ehdr *pe, *pe0 = map_virtual_page ((uint) pmm->pe | 3);
Elf32_Phdr *pph = (void *) pe0 + pe0->e_phoff;
void *pEntry = (void *) pe0->e_entry;
int i, c, j;
uint32 *stack_virt_addr;
uint32 page_count = 1;
/* find out how many pages for the module */
for (i = 0; i < pe0->e_phnum; i++) {
if (pph->p_type == PT_LOAD)
page_count += (pph->p_memsz >> 12);
pph = (void *) pph + pe0->e_phentsize;
}
/* now map the entire module */
pe = map_contiguous_virtual_pages ((uint) pmm->pe | 3, page_count);
unmap_virtual_page (pe0);
pph = (void *) pe + pe->e_phoff;
/* Populate ring 3 page directory with kernel mappings */
memcpy (&plPageDirectory[1023], (void *) (((uint32) get_pdbr ()) + 4092),
4);
/* LAPIC/IOAPIC mappings */
memcpy (&plPageDirectory[1019], (void *) (((uint32) get_pdbr ()) + 4076),
4);
/* Populate ring 3 page directory with entries for its private address
space */
plPageDirectory[0] = (uint32) plPageTable | 7;
plPageDirectory[1022] = (uint32) get_phys_addr (kls_pg_table[mod_num]) | 3;
kls_pg_table[mod_num][0] = (uint32) get_phys_addr (kl_stack[mod_num]) | 3;
/* Walk ELF header */
for (i = 0; i < pe->e_phnum; i++) {
if (pph->p_type == PT_LOAD) {
/* map pages loaded from file */
c = (pph->p_filesz + 0xFFF) >> 12; /* #pages to load for module */
for (j = 0; j < c; j++)
plPageTable[((uint32) pph->p_vaddr >> 12) + j] =
(uint32) pmm->pe + (pph->p_offset & 0xFFFFF000) + (j << 12) + 7;
/* zero remainder of final page */
memset ((void *) pe + pph->p_offset + pph->p_filesz,
0, (pph->p_memsz - pph->p_filesz) & 0x0FFF);
/* map additional zeroed pages */
c = (pph->p_memsz + 0xFFF) >> 12;
/* Allocate space for bss section. Use temporary virtual memory for
* memset call to clear physical frame(s)
*/
for (; j <= c; j++) {
uint32 page_frame = (uint32) alloc_phys_frame ();
void *virt_addr = map_virtual_page (page_frame | 3);
memset (virt_addr, 0, 0x1000);
plPageTable[((uint32) pph->p_vaddr >> 12) + j] = page_frame + 7;
unmap_virtual_page (virt_addr);
}
}
pph = (void *) pph + pe->e_phentsize;
}
