...

src/interrupts.c

@@ -1,6 +1,4 @@
 #include "interrupts.h"
-#include "vga.h"
-#include "kernel.h"
 #include "util.h"
 
 #define PIC1_COMMAND 0x20
@@ -8,24 +6,6 @@
 #define PIC2_COMMAND 0xA0
 #define PIC2_DATA 0xA1
 
-void pic_remap()
-{
-    outb(PIC1_COMMAND, 0x11);
-	outb(PIC2_COMMAND, 0x11);
-
-	outb(PIC1_DATA, 32);
-	outb(PIC2_DATA, 40);
-
-	outb(PIC1_DATA, 4);
-	outb(PIC2_DATA, 2);
-
-	outb(PIC1_DATA, 1);
-	outb(PIC2_DATA, 1);
-
-	outb(PIC1_DATA, 0);
-	outb(PIC2_DATA, 0);
-}
-
 static const char* exception_messages[32] = {
     "divide by zero",
     "debug",
@@ -61,14 +41,52 @@ static const char* exception_messages[32] = {
     "reserved",
 };
 
+static irq_handler_t irq_handlers[16] = {0};
+
+bool cpu_has_apic() {
+    uint32_t eax, edx;
+    cpuid(1, &eax, &edx);
+    return (edx & CPUID_FEAT_EDX_APIC) != 0;
+}
+
+void enable_apic() {
+    uint64_t apic_base = rdmsr(0x1B);
+    apic_base |= (1 << 11);
+    wrmsr(0x1B, apic_base);
+    kprintf("APIC enabled\n");
+}
+
+void remap_pic()
+{
+    outb(PIC1_COMMAND, 0x11);
+	outb(PIC2_COMMAND, 0x11);
+
+	outb(PIC1_DATA, 32);
+	outb(PIC2_DATA, 40);
+
+	outb(PIC1_DATA, 4);
+	outb(PIC2_DATA, 2);
+
+	outb(PIC1_DATA, 1);
+	outb(PIC2_DATA, 1);
+
+	outb(PIC1_DATA, 0);
+	outb(PIC2_DATA, 0);
+    kprintf("PIC remapped\n");
+}
+
+void disable_pic() {
+    outb(PIC1_DATA, 0xFF);
+    outb(PIC2_DATA, 0xFF);
+    kprintf("PIC disabled\n");
+}
+
 void handle_exception(const isr_frame_t* frame)
 {
     kprintf("exception[%d]: %s, error code: %d\n", frame->int_no, exception_messages[frame->int_no], frame->err_code);
     kpanic();
 }
 
-static irq_handler_t irq_handlers[16] = {0};
-
 void register_irq_handler(uint8_t irq, irq_handler_t handler)
 {
     if (irq >= 16)
@@ -78,6 +96,7 @@ void register_irq_handler(uint8_t irq, irq_handler_t handler)
     else
     {
         irq_handlers[irq] = handler;
+        kprintf("Registered irq handler at vector %d\n", irq);
     }
 }
 

src/interrupts.h

@@ -1,5 +1,6 @@
 #pragma once
 
+#include "kernel.h"
 #include <stdint.h>
 
 typedef struct
@@ -13,16 +14,22 @@ typedef struct
 
 typedef void (*irq_handler_t)(const isr_frame_t*);
 
-void pic_remap();
+void remap_pic();
+void disable_pic();
+
+bool cpu_has_apic();
+void enable_apic();
 
 void register_irq_handler(uint8_t irq, irq_handler_t handler);
 
 static inline void enable_interrupts()
 {
     __asm__ volatile("sti");
+    kprintf("Interrupts enabled\n");
 }
 
 static inline void disable_interrupts()
 {
     __asm__ volatile("cli");
+    kprintf("Interrupts disabled\n");
 }

src/kernel.c

@@ -4,7 +4,7 @@
 #include "string.h"
 #include "vga.h"
 #include <stdarg.h>
-#include <stddef.h>
+#include "multiboot.h"
 
 void handle_keypress(const keyboard_event_t* event)
 {
@@ -14,12 +14,18 @@ void handle_keypress(const keyboard_event_t* event)
     }
 }
 
-void kmain()
+void kmain(multiboot_info_t* multiboot_info)
 {
     vga_clear();
-    pic_remap();
+    remap_pic();
+
+    if (cpu_has_apic())
+    {
+        disable_pic();
+        enable_apic();
+    }
+
     enable_interrupts();
-    init_keyboard();
     register_keypress_handler(handle_keypress);
 
     kprintf("Welcome to nub OS\n");

src/multiboot.h

@@ -2,6 +2,18 @@
 
 #include <stdint.h>
 
+#define MULTIBOOT_FLAG_MEMIFO           0b0000000000001
+#define MULTIBOOT_FLAG_BOOT_DEVICE      0b0000000000010
+#define MULTIBOOT_FLAG_CMDLINE          0b0000000000100
+#define MULTIBOOT_FLAG_MODINFO          0b0000000001000
+#define MULTIBOOT_FLAG_MMAP             0b0000001000000
+#define MULTIBOOT_FLAG_DRIVES           0b0000010000000
+#define MULTIBOOT_FLAG_CONFIG_TABLE     0b0000100000000
+#define MULTIBOOT_FLAG_BOOTLOADER_NAME  0b0001000000000
+#define MULTIBOOT_FLAG_APM_TABLE        0b0010000000000
+#define MULTIBOOT_FLAG_VBEINFO          0b0100000000000
+#define MULTIBOOT_FLAG_FRAMEBUFFER_INFO 0b1000000000000
+
 typedef struct multiboot_info
 {
     uint32_t flags; // required

src/start.asm

@@ -14,7 +14,7 @@ section .multiboot
 
 section .bss
     align 16
-        resb 16384
+        resb 32768
     stack_top:
 
 section .bss
@@ -37,6 +37,11 @@ section .data
         dq gdt64
     .end:
 
+section .data
+    align 8
+    multiboot_info:
+        dq 0
+
 section .text
     bits 32
     _start:
@@ -48,6 +53,9 @@ section .text
         cmp eax, 0x2BADB002
         jne error
 
+        ; Save multiboot info pointer for later
+        mov [multiboot_info], ebx
+
         ; Check if cpuid is available by flipping bit 21
         ; in the eflags register and checking if the cpu flipped it back
         pushfd
@@ -93,10 +101,10 @@ section .text
         mov eax, pd
         or eax, 0x03
         mov [pdpt], eax
-        ; Fill pd with 2MB entries
+        ; Map first 32 2mb pages for the kernel for a total of 64mb
         mov edi, pd
         mov eax, 0x83
-        mov ecx, 512
+        mov ecx, 32
     .setup_pd:
         mov [edi], eax
         add eax, 0x200000
@@ -195,6 +203,7 @@ section .text
         lidt [idt64_descriptor]
 
         ; Finally, we call in to c
+        mov rdi, [multiboot_info]
         call kmain
     .hang:
         hlt

src/util.h

@@ -2,6 +2,71 @@
 
 #include <stdint.h>
 
+enum {
+    CPUID_FEAT_ECX_SSE3         = 1 << 0,
+    CPUID_FEAT_ECX_PCLMUL       = 1 << 1,
+    CPUID_FEAT_ECX_DTES64       = 1 << 2,
+    CPUID_FEAT_ECX_MONITOR      = 1 << 3,
+    CPUID_FEAT_ECX_DS_CPL       = 1 << 4,
+    CPUID_FEAT_ECX_VMX          = 1 << 5,
+    CPUID_FEAT_ECX_SMX          = 1 << 6,
+    CPUID_FEAT_ECX_EST          = 1 << 7,
+    CPUID_FEAT_ECX_TM2          = 1 << 8,
+    CPUID_FEAT_ECX_SSSE3        = 1 << 9,
+    CPUID_FEAT_ECX_CID          = 1 << 10,
+    CPUID_FEAT_ECX_SDBG         = 1 << 11,
+    CPUID_FEAT_ECX_FMA          = 1 << 12,
+    CPUID_FEAT_ECX_CX16         = 1 << 13,
+    CPUID_FEAT_ECX_XTPR         = 1 << 14,
+    CPUID_FEAT_ECX_PDCM         = 1 << 15,
+    CPUID_FEAT_ECX_PCID         = 1 << 17,
+    CPUID_FEAT_ECX_DCA          = 1 << 18,
+    CPUID_FEAT_ECX_SSE4_1       = 1 << 19,
+    CPUID_FEAT_ECX_SSE4_2       = 1 << 20,
+    CPUID_FEAT_ECX_X2APIC       = 1 << 21,
+    CPUID_FEAT_ECX_MOVBE        = 1 << 22,
+    CPUID_FEAT_ECX_POPCNT       = 1 << 23,
+    CPUID_FEAT_ECX_TSC          = 1 << 24,
+    CPUID_FEAT_ECX_AES          = 1 << 25,
+    CPUID_FEAT_ECX_XSAVE        = 1 << 26,
+    CPUID_FEAT_ECX_OSXSAVE      = 1 << 27,
+    CPUID_FEAT_ECX_AVX          = 1 << 28,
+    CPUID_FEAT_ECX_F16C         = 1 << 29,
+    CPUID_FEAT_ECX_RDRAND       = 1 << 30,
+    CPUID_FEAT_ECX_HYPERVISOR   = 1 << 31,
+
+    CPUID_FEAT_EDX_FPU          = 1 << 0,
+    CPUID_FEAT_EDX_VME          = 1 << 1,
+    CPUID_FEAT_EDX_DE           = 1 << 2,
+    CPUID_FEAT_EDX_PSE          = 1 << 3,
+    CPUID_FEAT_EDX_TSC          = 1 << 4,
+    CPUID_FEAT_EDX_MSR          = 1 << 5,
+    CPUID_FEAT_EDX_PAE          = 1 << 6,
+    CPUID_FEAT_EDX_MCE          = 1 << 7,
+    CPUID_FEAT_EDX_CX8          = 1 << 8,
+    CPUID_FEAT_EDX_APIC         = 1 << 9,
+    CPUID_FEAT_EDX_SEP          = 1 << 11,
+    CPUID_FEAT_EDX_MTRR         = 1 << 12,
+    CPUID_FEAT_EDX_PGE          = 1 << 13,
+    CPUID_FEAT_EDX_MCA          = 1 << 14,
+    CPUID_FEAT_EDX_CMOV         = 1 << 15,
+    CPUID_FEAT_EDX_PAT          = 1 << 16,
+    CPUID_FEAT_EDX_PSE36        = 1 << 17,
+    CPUID_FEAT_EDX_PSN          = 1 << 18,
+    CPUID_FEAT_EDX_CLFLUSH      = 1 << 19,
+    CPUID_FEAT_EDX_DS           = 1 << 21,
+    CPUID_FEAT_EDX_ACPI         = 1 << 22,
+    CPUID_FEAT_EDX_MMX          = 1 << 23,
+    CPUID_FEAT_EDX_FXSR         = 1 << 24,
+    CPUID_FEAT_EDX_SSE          = 1 << 25,
+    CPUID_FEAT_EDX_SSE2         = 1 << 26,
+    CPUID_FEAT_EDX_SS           = 1 << 27,
+    CPUID_FEAT_EDX_HTT          = 1 << 28,
+    CPUID_FEAT_EDX_TM           = 1 << 29,
+    CPUID_FEAT_EDX_IA64         = 1 << 30,
+    CPUID_FEAT_EDX_PBE          = 1 << 31
+};
+
 static inline void outb(uint16_t port, uint8_t val)
 {
     __asm__ volatile("outb %0, %1" : : "a"(val), "Nd"(port));
@@ -18,3 +83,19 @@ static inline void io_wait()
 {
     outb(0x80, 0);
 }
+
+static inline void cpuid(uint32_t code, uint32_t* a, uint32_t* d) {
+    __asm__ volatile("cpuid" : "=a"(*a), "=d"(*d) : "a"(code) : "ecx", "ebx");
+}
+
+static inline uint64_t rdmsr(uint32_t msr) {
+    uint32_t lo, hi;
+    __asm__ volatile("rdmsr" : "=a"(lo), "=d"(hi) : "c"(msr));
+    return ((uint64_t)hi << 32) | lo;
+}
+
+static inline void wrmsr(uint32_t msr, uint64_t value) {
+    uint32_t lo = (uint32_t)value;
+    uint32_t hi = (uint32_t)(value >> 32);
+    __asm__ volatile("wrmsr" : : "c"(msr), "a"(lo), "d"(hi));
+}

src/vga.c

@@ -31,8 +31,8 @@ void vga_put_char(char character, uint8_t color)
     }
     case '\t':
     {
-        uint8_t remainter = cursor_col % 4;
+        uint8_t remainder = 4 - (cursor_col % 4);
-        cursor_col += remainter == 0 ? 4 : remainter;
+        cursor_col += remainder;
         break;
     }
     case '\b':
@@ -86,13 +86,13 @@ void vga_put_char(char character, uint8_t color)
         {
             for (size_t col = 0; col < COLUMNS; col++)
             {
-                vga_buffer[COLUMNS * row - 1 + col] = vga_buffer[COLUMNS * row + col];
+                vga_buffer[COLUMNS * (row - 1) + col] = vga_buffer[COLUMNS * row + col];
             }
         }
 
         for (size_t col = 0; col < COLUMNS; col++)
         {
-            vga_buffer[ROWS - 1 + col] = (vga_char_t){
+            vga_buffer[COLUMNS * (ROWS - 1) + col] = (vga_char_t){
                 .character = ' ',
                 .color = VGA_DEFAULT_COLOR,
             };
@@ -108,7 +108,7 @@ void vga_clear()
     {
         for (size_t col = 0; col < COLUMNS; col++)
         {
-            vga_buffer[COLUMNS * row - 1 + col] = (vga_char_t){
+            vga_buffer[COLUMNS * row + col] = (vga_char_t){
                 .character = ' ',
                 .color = VGA_DEFAULT_COLOR,
             };