19. April 2024, 01:40
Beiträge anzeigen
Diese Sektion erlaubt es dir alle Beiträge dieses Mitglieds zu sehen. Beachte, dass du nur solche Beiträge sehen kannst, zu denen du auch Zugriffsrechte hast.
Übersicht
Wiki
Hilfe
Suche
Einloggen
Registrieren
__attribute__((aligned(8))) verwende.Global Descriptor Table (base=0x001003c8, limit=39):
GDT[0x00]=??? descriptor hi=0x00000000, lo=0x00000000
GDT[0x01]=??? descriptor hi=0x00000000, lo=0x00000000
GDT[0x02]=??? descriptor hi=0x00000000, lo=0x00000000
GDT[0x03]=??? descriptor hi=0x00000000, lo=0x00000000
GDT[0x04]=Code segment, base=0x00000000, limit=0xffffffff, Execute/Read, 32-bit
struct gdt_mapping {
uint64_t segment0 : 16;
uint64_t base0 : 24;
uint64_t accessed : 1;
uint64_t segment_r_rw : 1;
uint64_t direction : 1;
uint64_t exec : 1;
uint64_t segment : 1;
uint64_t privilege : 2;
uint64_t present : 1;
uint64_t segment1 : 4;
uint64_t zero : 2;
uint64_t size : 1;
uint64_t granularity : 1;
uint64_t base1 : 8;
} packed;
union gdt_entry {
uint64_t value;
struct gdt_mapping mapping;
};
ENTRY(_start)
OUTPUT(elf32-i386)
OUTPUT_ARCH(i386:i386)
PAGE_SIZE = 0x1000;
PHYS_ADDR = 0x100000;
VIRT_ADDR = 0xC0000000;
SECTIONS
{
. = PHYS_ADDR;
__boot_start = .;
.boot.text : AT(ADDR(.boot.text))
{
*(.multiboot)
*(.boot.text)
. = ALIGN(4096);
*(.gdt)
}
.boot.data : AT(ADDR(.boot.data))
{
*(.boot.data);
__export_start = .;
*(.export)
__export_end = .;
}
. = ALIGN(PAGE_SIZE);
__boot_end = .;
OFFSET = VIRT_ADDR - .;
. = VIRT_ADDR;
__rodata_pm_start = . - OFFSET;
__rodata_vm_start = .;
.text : AT(ADDR(.text) - OFFSET)
{
*(.text)
*(.rodata)
}
. = ALIGN(PAGE_SIZE);
__rodata_vm_end = .;
__rodata_pm_end = . - OFFSET;
__data_vm_start = .;
__data_pm_start = . - OFFSET;
.data : AT(ADDR(.data) - OFFSET)
{
__idt__ = . - OFFSET;
*(.idt)
*(.data)
*(.bss)
}
. = ALIGN(PAGE_SIZE);
__data_vm_end = .;
__data_pm_end = . - OFFSET;
/DISCARD/ :
{
*(.comment)
*(.eh_frame)
}
}
#define __gdt __attribute__((section(".gdt")))
#define __idt __attribute__((section(".idt")))
union gdt_entry __gdt gdt[GDT_SIZE] = {
{ .value = 0x0 },
{ .value = 0x0 },
{ .value = 0x0 },
{ .value = 0x0 },
{ .value = 0x0 }
};
{{value = 0, mapping = {segment0 = 0, base0 = 0, accessed = 0,
segment_r_rw = 0, direction = 0, exec = 0, segment = 0, privilege = 0,
present = 0, segment1 = 0, zero = 0, size = 0, granularity = 0, base1 = 0}},
{value = 58434644969848831, mapping = {segment0 = 65535, base0 = 0,
accessed = 0, segment_r_rw = 1, direction = 0, exec = 1, segment = 1,
privilege = 0, present = 1, segment1 = 15, zero = 0, size = 1,
granularity = 1, base1 = 0}}, {value = 58425848876826623, mapping = {
segment0 = 65535, base0 = 0, accessed = 0, segment_r_rw = 1, direction = 0,
exec = 0, segment = 1, privilege = 0, present = 1, segment1 = 15, zero = 0,
size = 1, granularity = 1, base1 = 0}}, {value = 58540198086115327,
mapping = {segment0 = 65535, base0 = 0, accessed = 0, segment_r_rw = 1,
direction = 0, exec = 1, segment = 1, privilege = 3, present = 1,
segment1 = 15, zero = 0, size = 1, granularity = 1, base1 = 0}}, {
value = 58531401993093119, mapping = {segment0 = 65535, base0 = 0,
accessed = 0, segment_r_rw = 1, direction = 0, exec = 0, segment = 1,
privilege = 3, present = 1, segment1 = 15, zero = 0, size = 1,
granularity = 1, base1 = 0}}}
/*
* this function sets the flags of one entry correctly
*/
static inline void __boot mmu_set_flags(vmm_space_p entry, char rw, char big) {
entry->present = 0x1;
entry->no_tlb_flush = 0x1;
if (rw)
entry->writable = 0x1;
if (big)
entry->big_page = 0x1;
}
/*
* this function maps physical memory, while paging is inactive
*/
void __boot mmu_map_offline(vmm_space_p space, void* vmem,
void* pmem, size_t size, char rw) {
vmm_space_p l1_tbl;
uint32_t mapped;
size_t alloc;
void* frame;
int l2, l1;
while (size) {
l2 = MMU_L2_INDEX(vmem);
if (!space[l2].present &&
size >= MMU_PAGE_SIZE_BIG && pse_feature) {
space[l2].frame = (uint32_t)pmem;
mmu_set_flags(&space[l2], rw, 1);
mapped = MMU_PAGE_SIZE_BIG;
}
else {
l1 = MMU_L1_INDEX(vmem);
//generate a l1 table
if (!space[l2].present) {
alloc = 0x1000;
frame = boot_malloc(&alloc);
if (!alloc) {
//TODO call panic
while (1);
}
boot_memset(frame, 0x0, 0x1000);
space[l2].frame = (uint32_t)frame;
mmu_set_flags(&space[l2], 1, 0);
}
l1_tbl = (vmm_space_p)((uint32_t)space[l2].frame);
l1_tbl[l1].frame = (uint32_t)pmem;
mmu_set_flags(&l1_tbl[l1], rw, 0);
mapped = MMU_PAGE_SIZE_NORM;
}
vmem += mapped;
pmem += mapped;
size -= mapped;
}
}
struct l2_entry {
uint32_t present : 1;
uint32_t writable : 1;
uint32_t userspace : 1;
uint32_t write_through : 1;
uint32_t no_cache : 1;
uint32_t dirty : 1;
uint32_t dirty_page : 1;
uint32_t big_page : 1;
uint32_t no_tlb_flush : 1;
uint32_t free : 3;
uint32_t frame: 20;
} packed;
struct l1_entry {
uint32_t present : 1;
uint32_t writable : 1;
uint32_t userspace : 1;
uint32_t write_through : 1;
uint32_t no_cache : 1;
uint32_t dirty : 1;
uint32_t dirty_page : 1;
uint32_t zero : 1;
uint32_t no_tlb_flush : 1;
uint32_t free : 3;
uint32_t frame: 20;
} packed;