Initial commit of FoolOS

FoolOS - the most useless OS in history.

8 files changed, 566 insertions, 0 deletions

diff --git a/boot/GDT.asm b/boot/GDT.asm
new file mode 100644
index 0000000..27514de
--- /dev/null
+++ b/boot/GDT.asm
@@ -0,0 +1,36 @@
+gdt_start:
+
+gdt_null:   ;null descriptor (2 x 4 bytes)
+    dd 0x0
+    dd 0x0
+
+gdt_code:
+    ; flags:
+    ; present: 1 / privilege: 00 / type: 1
+    ; code: 1 / conforming: 0 / readable: 1 / accessed: 0
+    ; granularity: 1 / 32-bit default: 1 / 64-bit seg: 0 / AVL: 0
+    dw 0xffff	    ;limit
+    dw 0x0	    ;base
+    db 0x0	    ;base
+    db 10011010b    ;flags
+    db 11001111b    ;flags & seg.limit
+    db 0x0	    ;base
+
+gdt_data:
+    ; flags:
+    ; code: 0 / expand down: 0 / writable: 1 / accessed: 0
+    dw 0xffff
+    dw 0x0
+    db 0x0
+    db 10010010b
+    db 11001111b
+    db 0x0
+
+gdt_end:
+
+gdt_descriptor:
+    dw gdt_end-gdt_start-1
+    dd gdt_start
+
+CODE_SEG equ gdt_code - gdt_start
+DATA_SEG equ gdt_data - gdt_start
diff --git a/boot/common.asm b/boot/common.asm
new file mode 100644
index 0000000..02e1a0b
--- /dev/null
+++ b/boot/common.asm
@@ -0,0 +1,105 @@
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;;;;;;; Miguel's FoolOS Helper Functions ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+[bits 16]
+
+
+;global data
+STR_HEX_OUT:
+    db "0x0000",0
+
+;print_string routine ([bx])
+;this routine will print a null terminated string at [bx] to the screen.
+print_string:
+
+    pusha			;push all registers
+    mov ah,0x0e
+
+    print_string_loop:
+
+	;check if value at [bx] is "\0" (end of string)
+	mov cl,[bx]
+	cmp cl,0
+	je print_string_finish
+
+	;otherwise instruct BIOS to print the current char
+	mov al,cl
+	int 0x10
+
+	;proceed with next char
+        inc bx
+	jmp print_string_loop
+
+    print_string_finish:
+
+    popa			;pop all registers
+    ret				;return to caller
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+;print_hex routine (dx)
+;will print the value of the bx register as hex to the screen
+print_hex:
+
+    pusha
+
+    ;begin with last hex val (hex_out[5])
+    mov bx,STR_HEX_OUT+5
+
+    ;lets loop throuth all 4 'digits'
+    print_hex_loop:
+
+    ;get least significan hex digit to cx
+    mov cx,dx
+    and cx,0x000F
+
+    ;check range (0-9 vs a-f)
+    cmp cx,10
+    jl print_hex_setnum
+
+    ;set hex a-f
+    mov al,'A'-10		
+    add al,cl
+    jmp print_hex_al
+
+    ;set hex 0-9
+    print_hex_setnum:
+    mov al,'0'		
+    add al,cl
+
+    ; set hex_out[bx] to al
+    print_hex_al:
+    mov [bx],al
+
+    ;proceed with the next significant hex 'digit'
+    dec bx
+    shr dx,4
+
+    ;check if finished (otherwise loop)
+    cmp bx,STR_HEX_OUT+1
+    jne print_hex_loop
+
+    ;output complete hex string and return to caller
+    mov bx,STR_HEX_OUT
+    call print_string
+    popa
+    ret
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+;disk_load routune (load dh sectors from drive dl to es:bx)
+disk_load:
+
+    pusha
+
+    mov ah,0x02		;BIOS read sector func
+    mov al,dh		;read dh sectors (amount)
+    mov ch,0x00		;cyl 0
+    mov dh,0x00		;head 0
+    mov cl,0x02		;start at sector 2
+
+    int 0x13		;bios interrupt
+
+    popa
+    ret
+
diff --git a/boot/common_pm.asm b/boot/common_pm.asm
new file mode 100644
index 0000000..40bc32f
--- /dev/null
+++ b/boot/common_pm.asm
@@ -0,0 +1,76 @@
+[bits 32]
+
+VIDEO_MEM equ 0xb8000
+WHITE_ON_BLACK equ 0x0f
+
+;global data
+STR_HEX_OUT_PM:
+    db "0x0000",0
+
+; print [ebx] at ecx
+print_string_pm:
+    pusha
+    mov edx, VIDEO_MEM
+    add edx,ecx
+    print_string_pm_loop:
+    mov al,[ebx]
+    mov ah, WHITE_ON_BLACK
+    cmp al,0
+    je print_string_pm_done
+    mov [edx],ax
+    add ebx,1
+    add edx,2
+    jmp print_string_pm_loop
+
+print_string_pm_done:
+    popa
+    ret
+
+;print_hex_pm routine (dx) at ecx
+;will print the value of the bx register as hex to the screen
+print_hex_pm:
+
+    pusha
+   
+
+    ;begin with last hex val (hex_out[5])
+    mov bx,STR_HEX_OUT_PM+5
+
+    ;lets loop throuth all 4 'digits'
+    print_hex_pm_loop:
+
+    ;get least significan hex digit to cx
+    mov cx,dx
+    and cx,0x000F
+
+    ;check range (0-9 vs a-f)
+    cmp cx,10
+    jl print_hex_pm_setnum
+
+    ;set hex a-f
+    mov al,'A'-10		
+    add al,cl
+    jmp print_hex_pm_al
+
+    ;set hex 0-9
+    print_hex_pm_setnum:
+    mov al,'0'		
+    add al,cl
+
+    ; set hex_out[bx] to al
+    print_hex_pm_al:
+    mov [bx],al
+
+    ;proceed with the next significant hex 'digit'
+    dec bx
+    shr dx,4
+
+    ;check if finished (otherwise loop)
+    cmp bx,STR_HEX_OUT_PM+1
+    jne print_hex_pm_loop
+
+    ;output complete hex string and return to caller
+    popa
+    mov bx,STR_HEX_OUT_PM
+    call print_string_pm
+    ret
diff --git a/boot/fill.asm b/boot/fill.asm
new file mode 100644
index 0000000..1717006
--- /dev/null
+++ b/boot/fill.asm
@@ -0,0 +1 @@
+times 2000000 db 0xff
diff --git a/boot/kernel_entry.asm b/boot/kernel_entry.asm
new file mode 100644
index 0000000..77bb2a5
--- /dev/null
+++ b/boot/kernel_entry.asm
@@ -0,0 +1,10 @@
+[bits 32]
+
+[extern kernel_main]
+[extern int0]
+
+call kernel_main ; jumps in the world of C
+call int0 ; jumps in the world of C
+ret
+
+jmp $
diff --git a/boot/mbr.asm b/boot/mbr.asm
new file mode 100644
index 0000000..41568c4
--- /dev/null
+++ b/boot/mbr.asm
@@ -0,0 +1,255 @@
+;;;;;;;;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;
+;    FoolOS Boot Loader
+;    
+;    Copyright 2014 M.Idziorek  <m.i@gmx.at>
+;    
+;    we have just been loaded by the BIOS and are in 16-bits real mode!
+;
+;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+;we want 16-bit instructions, before we switch to 32-bit protected mode.
+[bits 16]
+
+;define origin of boot record in memory: 0x7c00
+;this is where the BIOS per definition will put the first 
+;512 bytes of data from the boot device
+;The Boot record is identified by the last 2 magic bytes: 0xaa55 (?)
+[org 0x7c00]
+
+;define where we will load our kernel into memory
+KERNEL_OFFSET equ 0x1000
+
+jmp boot_16 ;start boot process
+
+;Global Data
+INT_COUNT:
+    db 0
+STR_VERSION:
+    db "_<-Fool-Loader~0.0.8~",0
+STR_PROT:
+    db "Entered 32-bit Protected Mode.",0
+STR_LOADED:
+    db "FoolOS Kernel Loaded.",0
+BOOT_DRIVE:
+    db 0
+
+[bits 32]
+; default interrupt handler
+interrupt:
+
+    mov	al, 0xA0	; set bit 4 of OCW 2
+    out	0xA0, al	; write to primary PIC command register
+
+    mov	al, 0x20	; set bit 4 of OCW 2
+    out	0x20, al	; write to primary PIC command register
+
+    iret
+
+;handle keyboard interrupt
+interrupt2:
+
+
+;    mov eax,[INT_COUNT]
+;    inc eax
+;    mov [INT_COUNT],eax
+
+    in al,0x60
+    mov	[INT_COUNT],al
+
+;    call KERNEL_OFFSET+(idt_end-idt_start)+1    ;jump into our Kernel it
+
+						; will follow our
+						; interrupt table
+
+   ; out 0x60,al
+
+
+    mov	al, 0x20	; set bit 4 of OCW 2
+    out	0x20, al	; write to primary PIC command register
+
+    iret
+
+;lets put our temporary GDT (Global Descriptor Table) here
+%include "boot/GDT.asm"
+
+;include 16-bit real mode routines (print_string, print_hex, disk_load)
+%include "boot/common.asm"
+
+;include 32-bit Protected Mode routines (print_string_pm,print_hex_pm)
+%include "boot/common_pm.asm"
+
+;include our routines for switching to 32-bit protected mode
+%include "boot/pm.asm"
+
+;;;;;;;; BOOT 16-bit real ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+;lets start
+[bits 16]
+boot_16:
+
+    ;setup the stack
+    mov bp,0x8000
+    mov sp,bp
+
+    ;remember BOOT_DRIVE (as was set by BIOS)
+    mov [BOOT_DRIVE],dl	
+    
+    ;print FoolOS version info
+    mov bx, STR_VERSION
+    call print_string
+
+    ;Load the KERNEL
+    mov bx,KERNEL_OFFSET
+    mov dh, 15
+    mov dl, [BOOT_DRIVE]
+    call disk_load
+
+    mov bx, STR_LOADED
+    call print_string
+
+    ;lets enter Protected mode!
+    call switch_to_pm
+
+;;;;;;;; BOOT 32-bit protected mode;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+[bits 32]
+boot_32_pm:
+
+    mov ecx,160
+    mov ebx,STR_PROT
+    call print_string_pm
+
+    ;enable A20
+    ;http://www.brokenthorn.com/Resources/OSDev9.html
+    ;Method 3.1: Enables A20 through keyboard controller
+    mov al, 0xdd	; command 0xdd: enable a20
+    out 0x64, al	; send command to controller
+
+    lidt [idt_descriptor]	;load descriptor table!
+
+    ;pollkb example
+;    pollkb:
+;	mov cx,320
+;	mov ax,0
+;	in al,0x60
+;	mov dx,ax
+;	call print_hex_pm
+;    jmp pollkb
+;
+    ;mov al,11111101b
+    ;out	0x61, al
+    
+
+    sti				;enable interrupts
+
+;************************************************************************
+; Map the 8259A PIC to use interrupts 32-47 within our interrupt table
+;************************************************************************
+ 
+%define ICW_1 0x11				; 00010001 binary. Enables initialization mode and we are sending ICW 4
+ 
+%define PIC_1_CTRL 0x20				; Primary PIC control register
+%define PIC_2_CTRL 0xA0				; Secondary PIC control register
+ 
+%define PIC_1_DATA 0x21				; Primary PIC data register
+%define PIC_2_DATA 0xA1				; Secondary PIC data register
+ 
+%define IRQ_0	0x20				; IRQs 0-7 mapped to use interrupts 0x20-0x27
+%define IRQ_8	0x28				; IRQs 8-15 mapped to use interrupts 0x28-0x36
+ 
+MapPIC:
+ 
+; Send ICW 1 - Begin initialization -------------------------
+ 
+	; Setup to initialize the primary PIC. Send ICW 1
+ 
+	mov	al, ICW_1
+	out	PIC_1_CTRL, al
+ 
+; Send ICW 2 - Map IRQ base interrupt numbers ---------------
+ 
+	; Remember that we have 2 PICs. Because we are cascading with this second PIC, send ICW 1 to second PIC command register
+ 
+	out	PIC_2_CTRL, al
+ 
+	; send ICW 2 to primary PIC
+ 
+	mov	al, IRQ_0
+	out	PIC_1_DATA, al
+ 
+	; send ICW 2 to secondary controller
+ 
+	mov	al, IRQ_8
+	out	PIC_2_DATA, al
+ 
+; Send ICW 3 - Set the IR line to connect both PICs ---------
+ 
+	; Send ICW 3 to primary PIC
+ 
+	mov	al, 0x4			; 0x04 => 0100, second bit (IR line 2)
+	out	PIC_1_DATA, al		; write to data register of primary PIC
+ 
+	; Send ICW 3 to secondary PIC
+ 
+	mov	al, 0x2			; 010=> IR line 2
+	out	PIC_2_DATA, al		; write to data register of secondary PIC
+ 
+; Send ICW 4 - Set x86 mode --------------------------------
+ 
+	mov	al, 1			; bit 0 enables 80x86 mode
+ 
+	; send ICW 4 to both primary and secondary PICs
+ 
+	out	PIC_1_DATA, al
+	out	PIC_2_DATA, al
+ 
+; All done. Null out the data registers
+ 
+	mov	al, 0
+	out	PIC_1_DATA, al
+	out	PIC_2_DATA, al
+	
+	;mask
+in	al, 0x21		; read in the primary PIC Interrupt Mask Register (IMR)
+and	al, 0x00		; 0xEF => 11101111b. This sets the IRQ4 bit (Bit 5) in AL
+out	0x21, al		; write the value back into IMR
+
+
+in	al, 0xA1		; read in the primary PIC Interrupt Mask Register (IMR)
+and	al, 0x00		; 0xEF => 11101111b. This sets the IRQ4 bit (Bit 5) in AL
+out	0xA1, al		; write the value back into IMR
+
+
+
+    call KERNEL_OFFSET+(idt_end-idt_start)    ;jump into our Kernel it
+						; will follow our
+						; interrupt table
+
+idt_descriptor:
+    dw idt_end-idt_start-1
+    dd KERNEL_OFFSET
+
+
+;;;; DEBUGGING STUFF
+times 8 db '@'
+dw interrupt
+db '@'
+dw interrupt2
+
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+;so we get identified as MBR
+times 510-($-$$) db 0
+dw 0xaa55
+
+;interrupt descriptor table (hardcoded address of interrupts:)
+idt_start:
+times 33 db 0x50,0x7c,0x08,0x00,0x00,10001110b,0x0,0x0
+db 0x59,0x7c,0x08,0x00,0x00,10001110b,0x0,0x0
+times 253 db 0x50,0x7c,0x08,0x00,0x00,10001110b,0x0,0x0
+idt_end:
+
+
+
+
diff --git a/boot/old.asm b/boot/old.asm
new file mode 100644
index 0000000..a7a1b24
--- /dev/null
+++ b/boot/old.asm
@@ -0,0 +1,56 @@
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+;read data from disk
+;mov bx,0x9000		;destination(es:bx)
+;mov dh,1		;number of sectors
+;mov dl,[BOOT_DRIVE]	;source disk
+;call disk_load
+
+;print data loaded form disk
+;mov dx,[0x9000]
+;call print_hex
+
+;mov dx,[0x9000+256]
+;call print_hex
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+;;;;; COM1 infinite loop ;;;;;
+;
+;    COM1_PORT equ 0xD000
+;    mov dx,COM1_PORT
+;    mov ecx,160*2
+;
+;    ; loop and write all data other than 0x0
+;    com1_loop:
+;
+;	in ax,dx ; read port val
+;	
+;	cmp ax,0xffff
+;	je com1_skip
+;
+;	cmp ax,0x0
+;	je com1_skip
+;
+;	call print_hex_pm
+;	add ecx,14
+;    	pusha
+;	    mov dx,ax
+;	    call print_hex_pm
+;	popa
+;	add ecx,26
+;
+;	com1_skip:
+;    
+;	inc dx
+;	;call print_hex_pm
+;	cmp dx,COM1_PORT+0x300
+;	jne com1_loop
+;	mov dx,COM1_PORT
+;	mov ecx,160*2
+;	jmp com1_loop
+;
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
diff --git a/boot/pm.asm b/boot/pm.asm
new file mode 100644
index 0000000..c66ab4f
--- /dev/null
+++ b/boot/pm.asm
@@ -0,0 +1,27 @@
+[bits 16]
+switch_to_pm:
+
+    cli				;switch off interrupts!
+    lgdt [gdt_descriptor]	;load descriptor table!
+
+    ;switch on 32-bit protected mode
+    mov eax, cr0
+    or eax,0x1 
+    mov cr0, eax
+
+    jmp CODE_SEG:init_pm
+
+[bits 32]
+init_pm:
+
+    mov ax, DATA_SEG
+    mov ds, ax
+    mov ss, ax
+    mov es, ax
+    mov fs, ax
+    mov gs, ax
+
+    mov ebp, 0x90000
+    mov esp, ebp
+
+    call boot_32_pm	    ;continue booting in 32-bit protected mode