mirror of
https://github.com/gbowne1/ClassicOS.git
synced 2025-10-13 05:05:07 -07:00
fixing the keyboard and bootloader so that its 2 stage again
This commit is contained in:
@@ -1,67 +1,230 @@
|
||||
; ==============================================================================
|
||||
; boot.asm - First Stage Bootloader (CHS Based)
|
||||
; ==============================================================================
|
||||
|
||||
[BITS 16]
|
||||
[ORG 0x7C00]
|
||||
|
||||
start:
|
||||
cli
|
||||
cli ; Disable interrupts
|
||||
|
||||
mov [bootdev], dl ; Save boot device number (from BIOS in DL)
|
||||
|
||||
; Setup stack safely below EBDA area (choose 0x0000:0x7A00)
|
||||
xor ax, ax ; AX = 0
|
||||
mov ss, ax ; Stack segment = 0x0000
|
||||
mov sp, 0x7A00 ; Stack offset = 0x7A00
|
||||
|
||||
; Initialize DS, ES for zero-based segments
|
||||
xor ax, ax
|
||||
mov ds, ax
|
||||
mov es, ax
|
||||
mov ss, ax
|
||||
mov sp, 0x7C00
|
||||
|
||||
; Load second-stage bootloader (boot1.asm) to 0x7E00
|
||||
mov si, 0x7E00 ; Destination offset (ES already zero, so physical 0x7E00)
|
||||
mov al, 1 ; Number of sectors to read (adjust if needed)
|
||||
mov cl, 1 ; Starting sector (CHS - sector number, 1-based)
|
||||
call read_chs
|
||||
jc disk_error ; Jump if carry set (read error)
|
||||
|
||||
; Load kernel to 0x100000 (1 MB)
|
||||
mov si, 0x0000 ; Destination offset
|
||||
mov ax, 0x1000 ; ES = 0x1000 (0x1000:0x0000 = 1 MB)
|
||||
mov es, ax
|
||||
xor bx, bx
|
||||
mov al, 16 ; Number of sectors for kernel (example)
|
||||
mov cl, 2 ; Starting sector (adjust as per your disk layout)
|
||||
call read_chs
|
||||
jc disk_error
|
||||
|
||||
; Memory Validation: Verify checksum of second stage bootloader
|
||||
mov si, 0x7E00 ; Start of second stage
|
||||
mov cx, 512 ; Size in bytes (adjust if more sectors loaded)
|
||||
call verify_checksum
|
||||
jc disk_error ; Jump if checksum fails
|
||||
|
||||
; Enable A20 line
|
||||
call enable_a20
|
||||
jc a20_error ; Jump if A20 enable fails
|
||||
|
||||
; Setup Global Descriptor Table
|
||||
call setup_gdt
|
||||
|
||||
; Switch to protected mode and jump to second stage at 0x08:0x7E00
|
||||
call switch_to_pm
|
||||
|
||||
; ----------------------
|
||||
; A20 Gate Enable (Fast method)
|
||||
disk_error:
|
||||
mov si, disk_error_msg
|
||||
call print_string_16
|
||||
jmp halt
|
||||
|
||||
a20_error:
|
||||
mov si, a20_error_msg
|
||||
call print_string_16
|
||||
jmp halt
|
||||
|
||||
; ----------------------------------------------------------------
|
||||
; Verify Checksum Routine
|
||||
; Uses SI = start address, CX = byte count
|
||||
; Simple XOR checksum over bytes, expects result 0
|
||||
|
||||
verify_checksum:
|
||||
push ax
|
||||
push bx
|
||||
push di
|
||||
mov di, si
|
||||
xor al, al
|
||||
xor bx, bx
|
||||
|
||||
.verify_loop:
|
||||
lodsb
|
||||
xor bl, al
|
||||
loop .verify_loop
|
||||
|
||||
test bl, bl
|
||||
jz .checksum_ok
|
||||
stc ; Set carry on checksum error
|
||||
jmp .done
|
||||
|
||||
.checksum_ok:
|
||||
clc ; Clear carry on success
|
||||
|
||||
.done:
|
||||
pop di
|
||||
pop bx
|
||||
pop ax
|
||||
ret
|
||||
|
||||
; ----------------------------------------------------------------
|
||||
; CHS Disk Read Routine
|
||||
; AL = number of sectors
|
||||
; CL = starting sector (1-based)
|
||||
; SI = destination offset (Segment:ES already set)
|
||||
read_chs:
|
||||
pusha
|
||||
push dx
|
||||
mov cx, 5
|
||||
.retry:
|
||||
mov ah, 0x02 ; BIOS read sector
|
||||
mov dl, [bootdev] ; Drive number
|
||||
int 0x13
|
||||
|
||||
jc .error ; Carry flag set = error
|
||||
pop dx
|
||||
popa
|
||||
ret
|
||||
|
||||
.error:
|
||||
dec cx
|
||||
jz disk_error
|
||||
xor ah, ah
|
||||
int 0x13
|
||||
jmp .retry
|
||||
|
||||
; ----------------------------------------------------------------
|
||||
enable_a20:
|
||||
; Fast A20 gate method
|
||||
in al, 0x92
|
||||
or al, 0x02
|
||||
out 0x92, al
|
||||
; Fallback method (keyboard controller)
|
||||
jc .fallbackenable_a20:
|
||||
; Fast A20 method
|
||||
in al, 0x92
|
||||
or al, 0x02
|
||||
and al, 0xFE ; Clear bit 0 to avoid fast A20 issues on some systems
|
||||
out 0x92, al
|
||||
; Verify A20
|
||||
call check_a20
|
||||
jnc .done
|
||||
; Fallback method
|
||||
mov al, 0xAD
|
||||
out 0x64, al
|
||||
; ... (rest of keyboard controller code)
|
||||
.done:
|
||||
ret
|
||||
|
||||
; ----------------------
|
||||
; Set up a minimal GDT
|
||||
check_a20:
|
||||
in al, 0x64 ; Read keyboard controller status
|
||||
test al, 0x02 ; Check if input buffer is full
|
||||
jnz check_a20 ; Wait until empty
|
||||
|
||||
mov al, 0xD0 ; Command: read output port
|
||||
out 0x64, al
|
||||
|
||||
.wait_output:
|
||||
in al, 0x60 ; Read output port value
|
||||
test al, 0x02 ; Check A20 gate bit (bit 1)
|
||||
jnz .a20_enabled ; If set, A20 enabled
|
||||
|
||||
xor al, al ; Clear carry to indicate failure
|
||||
stc ; Set carry for failure, jc will jump
|
||||
|
||||
ret
|
||||
|
||||
.a20_enabled:
|
||||
clc ; Clear carry flag to indicate success
|
||||
ret
|
||||
|
||||
.fallback:
|
||||
mov al, 0xAD
|
||||
out 0x64, al
|
||||
mov al, 0xD0
|
||||
out 0x64, al
|
||||
in al, 0x60
|
||||
or al, 0x02
|
||||
mov al, 0xD1
|
||||
out 0x64, al
|
||||
mov al, 0xAE
|
||||
out 0x64, al
|
||||
ret
|
||||
|
||||
; ----------------------------------------------------------------
|
||||
gdt_start:
|
||||
dq 0x0000000000000000 ; null descriptor
|
||||
dq 0x00CF9A000000FFFF ; code segment descriptor
|
||||
dq 0x00CF92000000FFFF ; data segment descriptor
|
||||
dq 0x0000000000000000 ; Null descriptor
|
||||
dq 0x00CF9A000000FFFF ; 32-bit code segment (selector 0x08)
|
||||
dq 0x00CF92000000FFFF ; 32-bit data segment (selector 0x10)
|
||||
dq 0x00009A000000FFFF ; 16-bit code segment for real mode (selector 0x18)
|
||||
|
||||
gdt_descriptor:
|
||||
dw gdt_end - gdt_start - 1 ; size of GDT
|
||||
dd gdt_start ; address of GDT
|
||||
|
||||
dw gdt_end - gdt_start - 1
|
||||
dd gdt_start
|
||||
gdt_end:
|
||||
|
||||
setup_gdt:
|
||||
lgdt [gdt_descriptor]
|
||||
ret
|
||||
|
||||
; ----------------------
|
||||
; Switch to Protected Mode
|
||||
; ----------------------------------------------------------------
|
||||
switch_to_pm:
|
||||
cli
|
||||
mov eax, cr0
|
||||
or eax, 1
|
||||
mov cr0, eax
|
||||
jmp 0x08:protected_mode_entry
|
||||
; ----------------------
|
||||
; 32-bit Protected Mode Entry Point
|
||||
[BITS 32]
|
||||
protected_mode_entry:
|
||||
mov ax, 0x10 ; data segment selector
|
||||
mov ds, ax
|
||||
mov es, ax
|
||||
mov fs, ax
|
||||
mov gs, ax
|
||||
mov ss, ax
|
||||
mov esp, 0x90000
|
||||
jmp 0x08:0x7E00
|
||||
|
||||
; Kernel is assumed to be loaded at 0x100000
|
||||
jmp 0x08:0x100000
|
||||
; ----------------------------------------------------------------
|
||||
print_string_16:
|
||||
.loop:
|
||||
lodsb
|
||||
or al, al
|
||||
jz .done
|
||||
mov ah, 0x0E
|
||||
int 0x10
|
||||
jmp .loop
|
||||
.done:
|
||||
ret
|
||||
|
||||
disk_error_msg db "Disk error!", 0
|
||||
a20_error_msg db "A20 error!", 0
|
||||
|
||||
halt:
|
||||
cli
|
||||
hlt
|
||||
|
||||
bootdev db 0
|
||||
sectors_per_track dw 63
|
||||
heads_per_cylinder dw 255
|
||||
|
||||
; ----------------------
|
||||
; Boot signature
|
||||
times 510 - ($ - $$) db 0
|
||||
dw 0xAA55
|
||||
|
||||
Binary file not shown.
182
bootloader/boot1.asm
Normal file
182
bootloader/boot1.asm
Normal file
@@ -0,0 +1,182 @@
|
||||
; ==============================================================================
|
||||
; boot1.asm - Second Stage Bootloader (Fixed Real Mode Transition)
|
||||
; ==============================================================================
|
||||
|
||||
[BITS 32]
|
||||
global _start
|
||||
extern kmain
|
||||
|
||||
_start:
|
||||
; Set up segments
|
||||
mov ax, 0x10
|
||||
mov ds, ax
|
||||
mov es, ax
|
||||
mov fs, ax
|
||||
mov gs, ax
|
||||
mov ss, ax
|
||||
|
||||
; Stack (must be identity-mapped)
|
||||
mov esp, 0x90000
|
||||
|
||||
; CPU Feature Detection: check CPUID support
|
||||
pushfd ; Save flags
|
||||
pop eax
|
||||
mov ecx, eax
|
||||
xor eax, 1 << 21 ; Flip ID bit
|
||||
push eax
|
||||
popfd
|
||||
pushfd
|
||||
pop eax
|
||||
xor eax, ecx
|
||||
jz .no_cpuid ; CPUID unsupported if no change
|
||||
|
||||
; CPUID supported, verify features
|
||||
mov eax, 1
|
||||
cpuid
|
||||
; Check for paging support (bit 31 of edx)
|
||||
test edx, 1 << 31
|
||||
jz .no_paging_support
|
||||
|
||||
; Additional CPU feature checks could be added here
|
||||
|
||||
jmp .cpuid_check_done
|
||||
|
||||
.no_cpuid:
|
||||
mov si, no_cpuid_msg
|
||||
call print_string_16
|
||||
jmp halt
|
||||
|
||||
.no_paging_support:
|
||||
mov si, no_paging_msg
|
||||
call print_string_16
|
||||
jmp halt
|
||||
|
||||
.cpuid_check_done:
|
||||
|
||||
; Temporarily switch back to real mode
|
||||
cli
|
||||
mov eax, cr0
|
||||
and eax, 0x7FFFFFFE ; Clear PE & PG bits
|
||||
mov cr0, eax
|
||||
jmp 0x18:real_mode_entry
|
||||
|
||||
; ----------------------------------------------------------------
|
||||
[BITS 16]
|
||||
real_mode_entry:
|
||||
; Real mode for BIOS access (E820, VESA)
|
||||
xor ax, ax
|
||||
mov es, ax
|
||||
|
||||
; VESA call
|
||||
mov di, VbeControllerInfo
|
||||
mov ax, 0x4F00
|
||||
int 0x10
|
||||
jc vesa_error
|
||||
|
||||
; E820 memory map
|
||||
xor ebx, ebx
|
||||
mov edx, 0x534D4150
|
||||
mov di, MemoryMapBuffer
|
||||
mov [MemoryMapEntries], dword 0
|
||||
|
||||
.e820_loop:
|
||||
mov eax, 0xE820
|
||||
mov ecx, 24
|
||||
int 0x15
|
||||
jc e820_error
|
||||
add di, 24
|
||||
inc dword [MemoryMapEntries]
|
||||
test ebx, ebx
|
||||
jnz .e820_loop
|
||||
jmp .e820_done
|
||||
|
||||
e820_error:
|
||||
mov si, e820_error_msg
|
||||
call print_string_16
|
||||
jmp halt
|
||||
|
||||
vesa_error:
|
||||
mov si, vesa_error_msg
|
||||
call print_string_16
|
||||
|
||||
; Fallback: set VGA text mode 3 and continue
|
||||
mov ah, 0x00 ; BIOS Set Video Mode function
|
||||
mov al, 0x03 ; VGA 80x25 text mode
|
||||
int 0x10
|
||||
|
||||
; Clear screen
|
||||
mov ah, 0x06 ; Scroll up function
|
||||
mov al, 0 ; Clear entire screen
|
||||
mov bh, 0x07 ; Text attribute (gray on black)
|
||||
mov cx, 0 ; Upper-left corner
|
||||
mov dx, 0x184F ; Lower-right corner
|
||||
int 0x10
|
||||
|
||||
jmp .e820_done ; Continue booting without VESA graphics
|
||||
|
||||
.e820_done:
|
||||
; Back to protected mode
|
||||
cli
|
||||
mov eax, cr0
|
||||
or eax, 1
|
||||
mov cr0, eax
|
||||
jmp 0x08:protected_entry
|
||||
|
||||
; ----------------------------------------------------------------
|
||||
print_string_16:
|
||||
.loop:
|
||||
lodsb
|
||||
or al, al
|
||||
jz .done
|
||||
mov ah, 0x0E
|
||||
int 0x10
|
||||
jmp .loop
|
||||
.done:
|
||||
ret
|
||||
|
||||
e820_error_msg db "E820 Failed!", 0
|
||||
vesa_error_msg db "VESA Failed!", 0
|
||||
no_cpuid_msg db "No CPUID support detected!", 0
|
||||
no_paging_msg db "CPU lacks paging support!", 0
|
||||
|
||||
; ----------------------------------------------------------------
|
||||
[BITS 32]
|
||||
protected_entry:
|
||||
; Paging setup
|
||||
xor eax, eax
|
||||
mov edi, page_directory
|
||||
mov ecx, 1024
|
||||
rep stosd
|
||||
mov edi, page_table
|
||||
rep stosd
|
||||
|
||||
mov dword [page_directory], page_table | 0x3
|
||||
mov ecx, 1024
|
||||
mov edi, page_table
|
||||
mov eax, 0x00000003
|
||||
.fill_pages:
|
||||
mov [edi], eax
|
||||
add eax, 0x1000
|
||||
add edi, 4
|
||||
loop .fill_pages
|
||||
|
||||
mov eax, page_directory
|
||||
mov cr3, eax
|
||||
mov eax, cr0
|
||||
or eax, 0x80000000
|
||||
mov cr0, eax
|
||||
|
||||
jmp kmain
|
||||
|
||||
; ----------------------------------------------------------------
|
||||
; Data buffers and variables must be appropriately defined in your data section
|
||||
MemoryMapBuffer times 128 db 0 ; 128*24 bytes reserved for E820 memory map (adjust size as needed)
|
||||
MemoryMapEntries dd 0
|
||||
VbeControllerInfo times 512 db 0 ; Buffer for VESA controller info (adjust size as needed)
|
||||
|
||||
; Define page directory and page table aligned as needed (in your data section)
|
||||
align 4096
|
||||
page_directory times 1024 dd 0
|
||||
align 4096
|
||||
page_table times 1024 dd 0
|
||||
|
||||
@@ -1,10 +1,9 @@
|
||||
ENTRY(start)
|
||||
ENTRY(kmain)
|
||||
|
||||
SECTIONS {
|
||||
. = 1M;
|
||||
|
||||
.text : {
|
||||
*(.multiboot)
|
||||
*(.text*)
|
||||
}
|
||||
|
||||
|
||||
@@ -20,34 +20,40 @@ static const char scancode_map[128] = {
|
||||
};
|
||||
|
||||
// Interrupt handler for IRQ1
|
||||
void keyboard_callback() {
|
||||
uint8_t scancode = inb(KEYBOARD_DATA_PORT);
|
||||
void keyboard_callback(void) {
|
||||
uint8_t scancode = inb(0x60);
|
||||
|
||||
// Ignore key releases (scancodes with high bit set)
|
||||
if (scancode & 0x80)
|
||||
return;
|
||||
|
||||
char c = scancode_map[scancode];
|
||||
if (c && buffer_index < sizeof(key_buffer) - 1) {
|
||||
key_buffer[buffer_index++] = c;
|
||||
terminal_putchar(c); // Echo to terminal (optional)
|
||||
// Only handle key press (ignore key release)
|
||||
if (!(scancode & 0x80)) {
|
||||
char c = scancode_map[scancode];
|
||||
if (c && buffer_index < sizeof(key_buffer) - 1) {
|
||||
key_buffer[buffer_index++] = c;
|
||||
terminal_putchar(c);
|
||||
}
|
||||
}
|
||||
|
||||
// Send End of Interrupt (EOI) to the PIC
|
||||
outb(0x20, 0x20);
|
||||
}
|
||||
|
||||
|
||||
void keyboard_init() {
|
||||
register_interrupt_handler(33, keyboard_callback); // IRQ1 = int 33 (0x21)
|
||||
}
|
||||
|
||||
// Blocking read (returns one char)
|
||||
char keyboard_get_char() {
|
||||
while (buffer_index == 0);
|
||||
char c = key_buffer[0];
|
||||
while (buffer_index == 0); // Busy wait
|
||||
|
||||
// Shift buffer left
|
||||
char c;
|
||||
__asm__ __volatile__("cli");
|
||||
c = key_buffer[0];
|
||||
for (uint8_t i = 1; i < buffer_index; i++) {
|
||||
key_buffer[i - 1] = key_buffer[i];
|
||||
}
|
||||
buffer_index--;
|
||||
__asm__ __volatile__("sti");
|
||||
|
||||
return c;
|
||||
}
|
||||
|
||||
|
||||
@@ -11,6 +11,7 @@
|
||||
#include "kmalloc.h"
|
||||
#include "timer.h"
|
||||
#include "utils.h"
|
||||
#include "keyboard.h"
|
||||
|
||||
#define LPT1 0x378
|
||||
|
||||
@@ -54,6 +55,10 @@ void kmain(void) {
|
||||
timer_init(100); // 100 Hz (10 ms interval)
|
||||
serial_write("Timer initialized.\n");
|
||||
|
||||
terminal_write("Initializing keyboard...\n");
|
||||
keyboard_init();
|
||||
serial_write("Keyboard initialized.\n");
|
||||
|
||||
terminal_write("Getting memory map...\n");
|
||||
memory_map_entry_t mmap[32];
|
||||
uint32_t mmap_size = get_memory_map(mmap, 32);
|
||||
|
||||
@@ -4,17 +4,20 @@
|
||||
#include "terminal.h"
|
||||
#include "stdio.h"
|
||||
|
||||
static uint32_t tick = 0;
|
||||
static volatile uint32_t tick = 0;
|
||||
|
||||
void timer_callback(void) {
|
||||
tick++;
|
||||
|
||||
// Print every 100 ticks for debugging purposes
|
||||
|
||||
if (tick % 100 == 0) {
|
||||
char tick_msg[50];
|
||||
snprintf(tick_msg, sizeof(tick_msg), "Tick count: %u\n", tick);
|
||||
terminal_write(tick_msg);
|
||||
char buf[16];
|
||||
itoa(tick, buf, 10);
|
||||
terminal_write("Tick count: ");
|
||||
terminal_write(buf);
|
||||
terminal_write("\n");
|
||||
}
|
||||
|
||||
outb(0x20, 0x20); // EOI to PIC
|
||||
}
|
||||
|
||||
void timer_init(uint32_t frequency) {
|
||||
@@ -29,4 +32,4 @@ void timer_init(uint32_t frequency) {
|
||||
|
||||
uint32_t timer_get_ticks(void) {
|
||||
return tick;
|
||||
}
|
||||
}
|
||||
|
||||
Reference in New Issue
Block a user