192d4f04ed
a null pointer - due to optimization breaking.
113 lines
2.8 KiB
C
113 lines
2.8 KiB
C
#include <stdint.h>
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#include "print.h"
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#include "interrupt.h"
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#include "tss.c"
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typedef unsigned short word;
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char check_apic() {
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uint32_t eax, ebx, ecx, edx;
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asm("cpuid" : "=a"(eax), "=b"(ebx), "=c"(ecx), "=d"(edx) : "a"(1));
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return (edx & (1 << 9)) != 0;
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}
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char check_sse() {
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uint32_t eax, ebx, ecx, edx;
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asm("cpuid" : "=a"(eax), "=b"(ebx), "=c"(ecx), "=d"(edx) : "a"(1));
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return (edx & (1 << 25)) != 0;
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}
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void enable_sse() {
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asm volatile(
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"mov %%cr0, %%eax\n"
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"and $0xFFFB, %%ax\n"
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"or $0x2, %%ax\n"
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"mov %%eax, %%cr0\n"
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"mov %%cr4, %%eax\n"
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"or $0x600, %%ax\n"
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"mov %%eax, %%cr4\n"
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: : : "%eax"
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);
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}
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void print_flags() {
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uint32_t flags;
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asm volatile("pushfd\npop %%eax":"=a"(flags));
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printDword(flags, 0xB8000 + (160*4) + 50);
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}
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void print_cr0() {
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uint32_t reg;
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asm volatile("mov %%cr0, %%eax":"=a"(reg));
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printDword(reg, 0xB8000 + (160*5) + 50);
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}
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void print_cr3() {
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uint32_t reg;
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asm volatile("mov %%cr3, %%eax":"=a"(reg));
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printDword(reg, 0xB8000 + (160*5) + 50 + 8*2 + 2);
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}
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void print_cr4() {
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uint32_t reg;
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asm volatile("mov %%cr4, %%eax":"=a"(reg));
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printDword(reg, 0xB8000 + (160*5) + 50 + 8*4 + 4);
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}
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extern void enter_v86(uint32_t ss, uint32_t esp, uint32_t cs, uint32_t eip);
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extern void v86Code();
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extern void jmp_usermode_test();
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/*
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Real Mode Accessible (First MB)
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00000 - 02000 IVT
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01000 - 04000 Paging
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04000 - 07C00 Free
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07C00 - 08000 Boot
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08000 - 20000 Kernel Code
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20000 - 22080 TSS
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80000 - 90000 Real Mode Stack
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90000 - A0000 Free
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A0000 - FFFFF BIOS Area
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Protected Only (1MB+)
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100000 - Free
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*/
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void start() {
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word *vga_text = (word *)0xb8000;
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char h[] = "LuciaOS";
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for (int i = 0; i < sizeof(h); i++)
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*(char *)&vga_text[i] = h[i];
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uint32_t o;
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asm("mov %%esp, %%eax" : "=a"(o) : :);
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printDword(o, (uint16_t *)&vga_text[80]);
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asm("mov %%ebp, %%eax" : "=a"(o) : :);
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printDword(o, (uint16_t *)&vga_text[160]);
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//char c[] = "APIC support: ";
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//char apic;
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//printByte(apic = check_apic(), (short*)&vga_text[80*3 + sizeof(c) - 1]);
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//for (int i = 0; i < sizeof(c); i++)
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// *(char *)&vga_text[i+(80*3)] = c[i];
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//if (!apic) return;
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char sse_str[] = "SSE support: ";
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char sse;
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printByte(sse = check_sse(), (uint16_t*)&vga_text[80*4 + sizeof(sse_str) - 1]);
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for (int i = 0; i < sizeof(sse_str); i++)
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*(char *)&vga_text[i+(80*4)] = sse_str[i];
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if (!sse) return;
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enable_sse();
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// edit
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setup_interrupts();
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setup_tss();
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print_flags();
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print_cr0();
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print_cr3();
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print_cr4();
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FARPTR v86_entry = i386LinearToFp(v86Code);
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enter_v86(0x8000, 0xFF00, FP_SEG(v86_entry), FP_OFF(v86_entry));
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//jmp_usermode_test();
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}
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