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-rw-r--r--boot/boot16_entry.asm11
-rw-r--r--boot/common.asm115
-rw-r--r--boot/mbr.asm93
-rw-r--r--boot/mbr16.asm79
-rw-r--r--boot/print16.asm28
-rw-r--r--boot/test.asm48
6 files changed, 35 insertions, 339 deletions
diff --git a/boot/boot16_entry.asm b/boot/boot16_entry.asm
deleted file mode 100644
index e8d63be..0000000
--- a/boot/boot16_entry.asm
+++ /dev/null
@@ -1,11 +0,0 @@
-;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-;;;;;;; Miguel's FoolOS Helper Functions ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-;
-; this will be compiled to an object file and linked with the boot loader
-; to simplify the entrance!
-;
-;
-[bits 16]
-[extern boot_main]
-call boot_main ; jumps in the world of C
diff --git a/boot/common.asm b/boot/common.asm
deleted file mode 100644
index 323b54f..0000000
--- a/boot/common.asm
+++ /dev/null
@@ -1,115 +0,0 @@
-;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-;;;;;;; Miguel's FoolOS Helper Functions ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-;
-;print_string
-;print_hex
-;disk_load
-;
-;
-;
-;
-
-[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/mbr.asm b/boot/mbr.asm
index 32f1a6f..2beac7b 100644
--- a/boot/mbr.asm
+++ b/boot/mbr.asm
@@ -6,12 +6,31 @@
;
; we have just been loaded by the BIOS and are in 16-bits real mode!
;
-; THIS IS THE CENTRAL FILE OF THE BOOTLOADER, after we finished we
-; are inside the C kernel!
+; THIS IS THE CENTRAL FILE OF THE BOOTLOADER,
+;
+; after we are through,
+; the following work has been accomplished (chronologically):
+;
+; * BOOT_DRIVE is set
+;
+; * 50 sectors of our kernel are loaded at KERNEL_OFFSET from floppy
+;
+; * memoru map is available at MEMMAP_OFFSET
+; (look at MEMMEP_SIZE_OFFSET for number of entries)
+;
+; * the vesa mode specified by VESA_MODE_SELECT is set up
+; (at VESA_MODES, and VESA_MODE_INFO additional info structs are available)
+;
+; * 32-bit protected mode was set up.
+;
+; * A20 gate is open
+;
+; * PICs are configured
+;
+; * we are inside the C kernel!
;
;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-;we want 16-bit instructions, before we switch to 32-bit protected mode.
;define origin of boot record in memory: 0x7c00
;this is where the BIOS per definition will put the first
@@ -19,42 +38,34 @@
;The Boot record is identified by the last 2 magic bytes: 0xaa55 (?)
[org 0x7c00]
-;define where we will load our kernel into memory
+;define where we will load our kernel into memory and some
+;other memory locations
KERNEL_OFFSET equ 0x1000
MEMMAP_SIZE_OFFSET equ 0x7c00+0x600
MEMMAP_OFFSET equ 0x7c00+0x400
VESA_MODES equ 0x8300
VESA_MODE_INFO equ 0x8400
VESA_MODE_SELECT equ 0x4114
-;VESA_MODE_SELECT equ 0x411A
+;we want 16-bit instructions, before we switch to 32-bit protected mode.
[bits 16]
jmp boot_16 ;start boot process
+;SOME Global Data, mainly strings
BOOT_DRIVE:
db 0xff
-
-;SOME Global Data, mainly strings
STR_VERSION:
db "v0.2~",0
VESA_CHECK:
db "vesa check.",0
-;STR_PROT:
-; db "32-bit PM",0
-;STR_LOADED:
-; db "loaded",0
-
;lets put our temporary GDT (Global Descriptor Table) here
%include "boot/GDT.asm"
;include 16-bit real mode routines (print_string, disk_load)
-%include "boot/common.asm"
-%include "boot/print16.asm"
-
-;include 32-bit Protected Mode routines (print_string_pm,print_hex_pm)
-;%include "boot/common_pm.asm"
+%include "boot/disk_load_16.asm"
+%include "boot/print_string_16.asm"
;include our routines for switching to 32-bit protected mode
%include "boot/pm.asm"
@@ -62,7 +73,7 @@ VESA_CHECK:
;pic mapping
%include "boot/pic.asm"
-;memory map
+;get memory map
%include "boot/memmap.asm"
;;;;;;;; BOOT 16-bit real ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
@@ -82,21 +93,12 @@ boot_16:
;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
+ ;Load the KERNEL (50 sectors starting at sector 2)
mov bx,KERNEL_OFFSET
mov dh, 50 ;50 sectors!
mov dl, [BOOT_DRIVE]
call disk_load
- ;print info message that kernel was loaded
-; mov bx, STR_LOADED
-; call print_string
-
-
;get memory map from bios before we enter 32 bit protected mode
mov ax,0 ; set target address in es:di (0:offset)
mov es,ax
@@ -104,7 +106,8 @@ boot_16:
call BiosGetMemoryMap ; this will also put the number of entries
; of the memory map at MEMMAP_SIZE_OFFSET
- ;get vesa modes!
+ ;VESA: also setup vesa stuff before entering 32 bit protected mode
+ ;VESA: get all available vesa modes!
mov ax,0 ; set target address in es:di (0:offset)
mov es,ax
mov di,VESA_MODES
@@ -119,7 +122,7 @@ boot_16:
vesa_ok:
;
- ;get info on mode of interest
+ ;VESA: get vesa info on mode of interest
mov ax,0 ; set target address in es:di (0:offset)
mov es,ax
mov di,VESA_MODE_INFO
@@ -134,7 +137,7 @@ boot_16:
jmp vesa_err2
vesa_ok2:
- ;finally switch to the mode of choice!
+ ;VESA: finally switch to the mode of choice!
mov ax,0x4f02 ;vesa function: Set Mode
mov bx,VESA_MODE_SELECT
int 0x10
@@ -148,11 +151,6 @@ boot_32_pm:
; we could do ALL This inside the kernel!!!!!! TODO
- ;print info message that we are in protected mode!
-; 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
@@ -162,32 +160,11 @@ boot_32_pm:
;pic setup
call pic_setup
- call KERNEL_OFFSET ;jump into our Kernel it
-
-;idt_descriptor:
-; dw idt_end-idt_start-1
-; dd KERNEL_OFFSET
-;;;; DEBUGGING STUFF
-;times 8 db '@'
-;dw interrupt
-;times 8 db '@'
-;dw interrupt2
-;times 8 db '@'
+ call KERNEL_OFFSET ;jump into our Kernel!
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-
;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/mbr16.asm b/boot/mbr16.asm
deleted file mode 100644
index 1abc97d..0000000
--- a/boot/mbr16.asm
+++ /dev/null
@@ -1,79 +0,0 @@
-;;;;;;;;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;
-;
-; FoolOS Boot Loader for 16bit entry in C
-;
-; Copyright 2014 M.Idziorek <m.i@gmx.at>
-;
-; we have just been loaded by the BIOS and are in 16-bits real mode!
-;
-; THIS IS THE CENTRAL FILE OF THE 16bit BOOTLOADER, after we finished we
-; are inside 16bit C code!
-;
-;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-
-;we want 16-bit instructions, before we switch to 32-bit protected mode.
-
-;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 "C binary"
-BOOT_OFFSET equ 0x1000
-
-[bits 16]
-jmp boot_16 ;start boot process
-
-BOOT_DRIVE:
- db 0xff
-
-;SOME Global Data, mainly strings
-STR_VERSION:
- db "~ Fool Loader 16-bit, v0.1 ~",0
-
-;include 16-bit real mode routines (print_string, print_hex, disk_load)
-%include "boot/common.asm"
-%include "boot/print16.asm"
-
-;;;;;;;; BOOT 16-bit real ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-
-;lets start
-
-boot_16:
-
- ;print version info
- mov bx, STR_VERSION
- call print_string
-
- ;setup the stack
- mov bp,0x8000
- mov sp,bp
-
- ;remember BOOT_DRIVE (as was set by BIOS)
- mov [BOOT_DRIVE],dl
-
- ;Load BOOT LOADER from second sector (max 50 sectors)
- mov bx,BOOT_OFFSET ;destination in ram
- mov dh, 50 ;50 sectors
- mov dl, [BOOT_DRIVE] ;source drive
- call disk_load
-
- call BOOT_OFFSET ;jump into our C code
-
-;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-
-;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/print16.asm b/boot/print16.asm
deleted file mode 100644
index 5d8ad5c..0000000
--- a/boot/print16.asm
+++ /dev/null
@@ -1,28 +0,0 @@
-[bits 16]
-
-;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
diff --git a/boot/test.asm b/boot/test.asm
deleted file mode 100644
index 62110b6..0000000
--- a/boot/test.asm
+++ /dev/null
@@ -1,48 +0,0 @@
-[org 0x7c00]
-
-[bits 16]
-jmp boot_16 ;start boot process
-
-STR_VERSION:
-
- db "FoolOs~",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
-
-boot_16:
-
- mov bx, STR_VERSION
- call print_string
-
- jmp boot_16
-
-times 510-($-$$) db 0
-dw 0xaa55
-
-
-
generated by cgit v1.2.3 (git 2.25.1) at 2025-11-09 15:16:43 +0000