48 lines
1.4 KiB
C
Executable File
48 lines
1.4 KiB
C
Executable File
#include <Library/BaseLib.h>
|
|
#include <Library/MemoryAllocationLib.h>
|
|
#include <Library/PrintLib.h>
|
|
#include <Library/UefiLib.h>
|
|
#include <Uefi.h>
|
|
|
|
#include "io.h"
|
|
|
|
UINT64 SegmentDescriptors[] = {
|
|
0x0000000000000000, // NULL Descriptor
|
|
0x00AF9A000000FFFF, // BaseAddress 0 Granularity 1
|
|
// SegmentSize 1048575*4069=4294963200(4GB) Segment Present
|
|
// Plivilege 0 Code Segment Read+Exec
|
|
0x00CF93000000FFFF // BaseAddress 0 Granularity 1
|
|
// SegmentSize 1048575*4069=4294963200(4GB) Segment
|
|
// Present Plivilege 0 Data Segment Read+Write
|
|
};
|
|
IA32_DESCRIPTOR Descriptor;
|
|
|
|
void sendparallelstub(UINT8 byte) {
|
|
mapped_io_write(0x378, byte);
|
|
UINT8 control = mapped_io_read(0x37a);
|
|
mapped_io_write(0x37a, control | 1);
|
|
int a;
|
|
for (int i = 0; i < 200; i++) a += control;
|
|
mapped_io_write(0x37a, control);
|
|
}
|
|
|
|
void GDT_init() {
|
|
Descriptor.Limit = (UINT16)(sizeof(UINT64) * 3 - 1);
|
|
Descriptor.Base = (UINT32)(UINTN)(VOID *)SegmentDescriptors;
|
|
AsmWriteGdtr(&Descriptor);
|
|
asm volatile(
|
|
"mov $16, %ax\n"
|
|
"mov %ax, %ss\n"
|
|
"mov %ax, %ds\n"
|
|
"mov %ax, %es\n"
|
|
"mov %ax, %fs\n"
|
|
"mov %ax, %gs\n"
|
|
"sub $16,%rsp\n"
|
|
"leaq end(%rip),%rax\n"
|
|
"mov %rax,(%rsp)\n"
|
|
"mov $8,%ax\n"
|
|
"mov %ax,4(%rsp)\n"
|
|
"ljmp *(%rsp)\n"
|
|
"end:\n"
|
|
"add $16,%rsp");
|
|
} |