4 files changed, 337 insertions, 0 deletions
diff --git a/xxx/boot1/Makefile b/xxx/boot1/Makefile
new file mode 100644
index 0000000..b9b2e24
--- /dev/null
+++ b/xxx/boot1/Makefile
@@ -0,0 +1,13 @@
+#master boot record
+
+include ../Makefile.common
+
+MBR=mbr.bin
+
+ASM_SOURCES=$(wildcard *.asm)
+
+$(MBR): $(ASM_SOURCES)
+
+clean: 
+	-rm $(MBR)
+
diff --git a/xxx/boot1/disk_load_16.asm b/xxx/boot1/disk_load_16.asm
new file mode 100644
index 0000000..6d1e4b3
--- /dev/null
+++ b/xxx/boot1/disk_load_16.asm
@@ -0,0 +1,103 @@
+;
+;disk_load_16
+;
+
+[bits 16]
+
+STR_LBA:
+    db "LBA Support Detected",0
+    
+STR_CHS:
+    db "No CHS Support!)",0
+
+STR_ERROR:
+    db "Disk Read Error",0
+
+STR_DONE:
+    db "Stage 2 Loaded",0
+
+disk_load_16:
+
+    pusha
+    
+   ; check if LBA is supported
+    mov    ah,0x41
+    mov    bx,0x55aa
+    int    0x13                                                    
+    jnc disk_load_lba
+    jmp disk_load_chs
+
+disk_load_lba:
+
+    mov bx, STR_LBA
+    call print_string
+    call print_nextline
+
+    mov dl,[BOOT_DRIVE]
+    xor ah,ah
+    mov ah,0x42
+
+    mov bx,0
+    mov ds,bx
+    lea si,[lba_adr]        
+
+    int 0x13  
+    jnc disk_load_finish
+    jmp disk_load_error
+
+disk_load_chs:
+
+    mov bx, STR_CHS
+    call print_string
+    call print_nextline
+    jmp $
+
+    mov bx,0		;target es:bx
+    mov es,bx
+    mov bx,0x7e00
+
+    mov al,50		;number of sectors to read
+    mov ah,0x02		;BIOS read sector func
+
+    mov cl,2 ; sector
+    mov ch,0 ; cylinder
+
+    mov dl,[BOOT_DRIVE]
+    mov dh,0 ;head
+
+    int 0x13		;bios interrupt
+
+    jnc disk_load_finish  
+
+disk_load_error:
+
+    call print_nextline
+    mov bx, STR_ERROR
+    call print_string
+    call print_nextline
+    jmp $
+
+disk_load_finish:
+
+    call print_nextline
+    mov bx, STR_DONE
+    call print_string
+    call print_nextline
+
+
+    popa
+    ret
+  
+
+;; here we hold the lba addr
+lba_adr:
+
+    dw 0x10	    ; size of packet ( 16 byte)
+    dw 16	    ; number of sectors to read
+
+    ; target is 0x7e00
+    dw 0x7e00	    ; target addr. offset
+    dw 0x0000	    ; target addr. sector
+
+    dd 1	    ; first sector to read
+    dd 0 
diff --git a/xxx/boot1/mbr.asm b/xxx/boot1/mbr.asm
new file mode 100644
index 0000000..c0a555d
--- /dev/null
+++ b/xxx/boot1/mbr.asm
@@ -0,0 +1,106 @@
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;
+; FOOL-OS Master Boot Record
+;
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;
+; This is the Master Boot Record for x86
+;
+; We are limited to 512 bytes  (one sector)
+;   minus 64 bytes for the partition table
+;   minus 2 bytes formagic number (0xaa55)
+; 
+; all we do here is :
+;   
+;   1. Put the Stack at 0x07bff (it is counting down)
+;   2. Remeber Boot Drive at [BOOT_DRIVE]
+;   3. Print PR message and Boot Drive number
+;   4. Load Second Stage Bootloader from Boot Drive at next sector
+;   5. Show Info Message after successfull loading
+;   6. Jump to 2nd Stage Boot Loader
+;
+; Refer to a memory map as needed:
+; http://wiki.osdev.org/Memory_Map_(x86)
+
+; Everything here is 16bit
+[bits 16]
+
+; Per definition this will be loaded by the BIOS at 0x7c00
+[org 0x7c00]
+
+; skip constants and includes
+jmp stage1
+
+; string constants (null terminated)
+STR_1:	    db "Fool Loader Stage 1. v0.1",0
+STR_2:	    db "Starting Stage 2",0
+STR_BOOT:   db "Boot drive: ",0
+
+; some space (one byte) to remember the Boot Drive
+BOOT_DRIVE: db 0xff
+
+; include print and disk load routines
+%include "print_string_16.asm"
+%include "disk_load_16.asm"
+
+; Here we start!
+stage1:
+
+    ; first of all, setup the stack (right under our MBR)
+    ; ~30KB space guaranteed
+    mov bp,0x07bff
+    mov sp,bp
+
+    ; remember BOOT_DRIVE (as was set by BIOS in dl)
+    mov [BOOT_DRIVE],dl	
+
+    ; clear screen and print PR message
+    call print_clear
+    call print_nextline
+
+    mov bx, STR_1
+    call print_string
+    call print_nextline
+
+
+    ; print bootdrive number
+    mov bx, STR_BOOT
+    call print_string
+
+    mov al,[BOOT_DRIVE]
+    call print_hex_byte
+    call print_nextline
+
+
+    ; Actually Load the Second Stage Bootloader!
+    call disk_load_16
+
+
+    ; show info message that 2nd Stage was loaded
+    mov bx, STR_2
+    call print_string
+    call print_nextline
+    call print_nextline
+
+
+    ; save Boot Drive in dl for second stage
+    mov dl,[BOOT_DRIVE]
+
+
+    ; jump to the next sector where we loaded the 2nd stage
+    jmp 0x7e00
+
+
+    ; nothing essential under this line
+    ; we need this to follow some mbr standards
+
+    ; fill at least 4x16byte with zeroes. (partition table)
+    ; (otherwise my Acer Aspire will not boot)
+    times 64 db 0x0
+
+    ; fill rest with zeroes
+    times 510-($-$$) db 0x0
+
+    ; magic number so we get identified as MBR
+    dw 0xaa55
+
diff --git a/xxx/boot1/print_string_16.asm b/xxx/boot1/print_string_16.asm
new file mode 100644
index 0000000..9f81a87
--- /dev/null
+++ b/xxx/boot1/print_string_16.asm
@@ -0,0 +1,115 @@
+[bits 16]
+
+BLANK:
+    db 0x12
+
+SPACE:
+    db " ",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_clear:
+
+pusha
+    mov ah,0x6	    ;func
+    mov al,0	    ;scroll one line
+    mov bh,[BLANK]  ;blank char
+
+    mov ch,0	    ;upper left corner
+    mov cl,0
+    mov dh,20	    ;lower right corner
+    mov dl,40
+    int 0x10
+
+    mov ah,0x2
+    mov bh,0
+    mov dl,0
+    mov dh,20
+    int 0x10
+popa
+
+print_nextline:
+
+    pusha
+
+    mov ah,0x6	    ;func
+    mov al,1	    ;scroll one line
+    mov bh,[BLANK]  ;blank char
+
+    mov ch,0	    ;upper left corner
+    mov cl,0
+    mov dh,20	    ;lower right corner
+    mov dl,40
+    int 0x10
+
+
+    mov ah,0x3
+    mov bh,0
+    int 0x10
+
+
+    mov ah,0x2
+    mov dl,0
+    int 0x10
+
+    mov bx,SPACE
+    call print_string
+
+    popa
+    ret
+
+
+;print byte from al to screen
+ print_hex_byte: 
+
+ pusha
+
+   mov [.temp],al
+   shr al,4
+   cmp al,10
+   sbb al,69h
+   das
+ 
+   mov ah,0Eh
+   int 10h
+ 
+   mov al,[.temp]
+   ror al,4
+   shr al,4
+   cmp al,10
+   sbb al,69h
+   das
+ 
+   mov ah,0Eh
+   int 10h
+
+popa
+ 
+   ret
+ 
+ .temp db 0