Current status of the code

build.bash

@@ -1,12 +1,58 @@
-#!/bin/env bash
+#!/bin/bash
 
-cd bootsector
+echo "|==== Building the NightLoader with Build-Script v0.1 ====|"
-./build.sh
+echo " "
-cd ../
 
-cd stage_2
-./build.sh
-cd ../
 
-cat bootsector/stage_1.bin > nightloader.bin
+
-# cat stage_2/stage_2.bin >> nightloader.bin
+# Legacy Bootloader for old BIOS-platforms
+echo "STARTING TO BUILD LEGACY-BIOS LOADER!"
+
+# Build the stage-1 bootloader; the first disk-sector.
+cd code/legacy-bios/bootsector
+bash build.sh $1 $2
+mv bootsector.bin ../../../
+cd ..
+
+# Build the stage 2 - starter; it is just there to jump
+# to the *executable file* which the UEFI-codepath also uses.
+cd starter
+bash build.sh $1 $2
+mv starter.bin ../../../
+cd ../../../
+
+mv bootsector.bin       build/objects/
+mv starter.bin          build/objects/
+
+echo "FINISHED BUILDING LEGACY-BIOS LOADER"
+echo " "
+echo " "
+echo " "
+
+
+
+echo "Creating disk image for a basic NightLoader-installation"
+
+# Create the partition's image-file by allocating 256MB and
+# creating a FAT32 - partition which then resides there. 
+truncate -s 256M partition.bin
+mkfs.fat -F32 -nNIGHT partition.bin
+
+# Mount the partition-image to a specific directory (needs
+# root-permissions), copy over the freshly built binaries to
+# the path they belobng to and unmount the partition. 
+mount partition.bin partition/
+mkdir -p partition/nightloader/
+cp starter.bin partition/
+umount partition.bin
+mv partition.bin build/objects/
+
+# Create a disk image by including the first disk sector.
+cat build/objects/bootsector.bin        >   nightloader.bin
+cat build/objects/partition.bin         >>  nightloader.bin
+
+echo " "
+echo " "
+echo "Finished building the NightLoader!"
+echo " "
+

code/legacy-bios/bootsector/build.sh

@@ -1,3 +1,2 @@
-#!/bin/env bash
 
-nasm -fbin start.asm -o stage_1.bin
+nasm -fbin start.asm -o bootsector.bin

code/legacy-bios/bootsector/fat32.asm

@@ -1,4 +1,65 @@
 ; TODO: Read FAT32 filesystem and load raw binary from path nightloader/stage_2.bin
 
+FAT32_HEADER_ROOT_DIRECTORY_FAT_INDEX equ 0x2c
+
+find_stage_2:
+    
+    ; Set extra-segment to the address where the Stage 2 - partition is located.
+    mov bx, 0x2000
+    mov es, bx
+    mov ds, bx
+    
+    
+    
+    ; PART 1: FIND THE STAGE 2 - FILE'S OFFSET IN THE PARTITION
+    
+    ; Read cluster size (in bytes) into dx
+    mov bx, 0x000b
+    mov ax, [bx]
+    add bx, 2
+    mov di, [bx]
+    mul di
+    mov dx, ax
+    
+    ; Read the root directory's first cluster's index into si:di (si: upper, di: lower)
+    mov bx, FAT32_HEADER_ROOT_DIRECTORY_FAT_INDEX
+    mov di, [bx]
+    add bx, 2
+    mov si, [bx]
+    
+    push si
+    push di
+    
+    ; Put address of root directory into ds:bx
+    
+    ; Part 1: Get the overflow
+    ; mov bx, 
+    
+    
+    
+    
+    ; Loop through the root directory's entries
+.root_directory_loop: ; Loops through all the root directory's clusters
+    
+    mov di, [bx]
+    add bx, 2
+    mov si, [bx]
+    
+    
+    
+    ; Test for the root directory's "Last Cluster" - marker.
+    mov ax, [bx]
+    ; cmp 
+    jmp .root_directory_loop
+
+; Arguments:
+;   bx: 
+; Return Values:
+;   ax: The index of the FAT-entry in which the searched file was found.
+find_file_in_directory:
+    
+    
+    
+    
     
 

code/legacy-bios/bootsector/gdt.asm

@@ -0,0 +1,54 @@
+
+
+create_gdt:
+    mov bx, STAGE_1_GDT_MEMORY_ADDRESS
+    mov ds, bx
+    
+    mov bx, 8
+    mov di, 8
+.set_loop:
+    
+    mov ax, bx
+    and ax, 0b111
+    
+    mov [bx], byte 0xff
+    cmp ax, 0
+    je .set_loop_condition
+    
+    mov [bx], byte 0xff
+    cmp ax, 1
+    je .set_loop_condition
+    
+    mov [bx], byte 0xff
+    cmp ax, 2
+    je .set_loop_condition
+    
+    mov [bx], byte 0xff
+    cmp ax, 3
+    je .set_loop_condition
+    
+    mov [bx], byte 0xff
+    cmp ax, 4
+    je .set_loop_condition
+    
+    mov [bx], byte 0xff
+    cmp ax, 5
+    je .set_loop_condition
+    
+    mov [bx], byte 0xff
+    cmp ax, 6
+    je .set_loop_condition
+    
+    mov [bx], byte 0xff
+    cmp ax, 7
+    je .set_loop_condition
+    
+.set_loop_condition:
+    cmp bx, 48
+    jb .set_loop
+    
+    
+    
+    
+    ret
+

code/legacy-bios/bootsector/start.asm

@@ -2,7 +2,8 @@
 
 
 STAGE_1_CODE_MEMORY_ADDRESS                 equ 0x7c00
-STAGE_1_STACK_MEMORY_ADDRESS                equ 0x07e0
+STAGE_1_STACK_MEMORY_ADDRESS                equ 0x7e00  ; grows downwards
+STAGE_1_GDT_MEMORY_ADDRESS                  equ 0x7e00
 
 NIGHTLOADER_PARTITION_TYPE                  equ 0x9d
 
@@ -23,9 +24,9 @@ stage_0:
     
     mov bx, STAGE_1_STACK_MEMORY_ADDRESS
     mov ss, bx
-    mov bx, 0x0800
+    mov bx, 0x2000
-    mov bp, 256
+    mov bp, 512
-    mov sp, 256
+    mov sp, 512
     
     mov bx, 0x0000
     mov ds, bx
@@ -71,6 +72,8 @@ stage_0:
     
 .load_partition:
     
+    call create_gdt     ; TODO: Doesn't belong here!
+    
     mov si, cx          ; address of the partition table entry of the nightloader-partition
     
     ; TODO: Make this more flexible; that's urgent.
@@ -80,20 +83,22 @@ stage_0:
     mov     cl,     2               ; sector (starts at 1, max.: 63)
     mov     dx,     di              ; storage device id
     mov     dh,     0               ; head
-    mov     bx,     0x0800
+    mov     bx,     0x2000
     mov     es,     bx              ; read destination segment
     mov     bx,     0x0000          ; read destination address
     int 0x13
     
-    mov si, 0x8000
+    mov bx, 0x2000
+    mov ds, bx
+    
+    mov si, 0x0000
     mov cx, 8
     mov dh, 12
     mov dl, 36
     call print_string
     ; jmp .wait
     
-    jmp 0x0800:0x0000
+    jmp 0x2000:0x0000
-    
     
     
     
@@ -105,6 +110,8 @@ stage_0:
     mov dh, 12
     call print_string
     
+    
+    
 .wait:
     cli
     hlt
@@ -119,5 +126,6 @@ errors:
     db "0123456789abcdef"
 
 %include "utility.asm"
+%include "gdt.asm"
 %include "fat32.asm"
 %include "partition_table.asm"

code/legacy-bios/bootsector/utility.asm

@@ -1,4 +1,5 @@
 
+
 ; cx: len_buffer
 ; si: buffer
 ; dl: start_x       NOTE: Will contain the end of the text on-screen

code/legacy-bios/starter/build.sh

@@ -1,3 +1,3 @@
-#!/bin/env bash
+#!/bin/bash
 
 

run.bash

@@ -1,3 +1,3 @@
-#!/bin/env bash
+#!/bin/bash
 
 qemu-system-x86_64 nightloader.bin