did simplify multiboot header because loader may not be trusted

README.md

@@ -1,10 +1,10 @@
 # rOSka
 
  - Probably useless hobby OS project
- - Targets 32bit legacy systems with graphical framebuffer
+ - Targets 32bit legacy systems with graphical framebuffer (VESA VBE 2)
  - Boots with multiboot compatible bootloader, such as GRUB
  - Assembles with FASM
- - We'll probably use ext2 filesystem
+ - We'll probably use ext2/4 filesystem
 
 ## GRUB disk creation
  

roska.fasm

@@ -2,35 +2,27 @@ format binary
 use32
 org 0x100000
 
-MB_HEADER_MAGIC      equ 0x1BADB002
-MB_PAGE_ALIGN        equ (1 shl 0)
-MB_MEMORY_INFO       equ (1 shl 1)
-MB_VIDEO_REQUEST     equ (1 shl 2)
-MB_AOUT_KLUDGE       equ (1 shl 16)
-MB_HEADER_FLAGS      equ MB_PAGE_ALIGN or MB_MEMORY_INFO or MB_VIDEO_REQUEST
-MB_HEADER_FLAGS      equ MB_PAGE_ALIGN or MB_MEMORY_INFO or MB_VIDEO_REQUEST or MB_AOUT_KLUDGE
-MB_CHECKSUM          equ -(MB_HEADER_MAGIC + MB_HEADER_FLAGS)
-
-;; safe modes according to https://wiki.osdev.org/VESA_Video_Modes
-VWIDTH  equ 80 ; 640/720
-VHEIGHT equ 25 ; 480
-VDEPTH  equ 0  ; 24/32, zero in textmode
-
+; multiboot skips us to 32bit mode
+; 16bit mode required to set video mode
+; multiboot might not set our video mode (looking at you, syslinux!)
+; TODO: make the own bootloader and ditch multiboot
+; users can(will) have inexpensive small harddrives or usbs dedicated to this shit
 multiboot:
-	dd MB_HEADER_MAGIC
-	dd MB_HEADER_FLAGS
-	dd MB_CHECKSUM
-	dd multiboot	; header address
+	dd 0x1BADB002 ; magic
+	dd 00000000000000010000000000000000b ; aout kludge flag
+	dd 0xE4514FFE ; mboot checksum
+	dd 0x100000 ; header address
 	dd 0x100000 ; load address
-	dd bss_start	; load end address
-	dd bss_end	; bss end address
-	dd start	; entry address
-
-	dd 1	; video mode_type (0:fb, 1:txt) (set flags[2]!)
-	dd VWIDTH	; video width
-	dd VHEIGHT	; video height
-	dd VDEPTH	; video depth
+	dd 0 ; load end address, 0=assume whole file
+	dd 0 ; bss end address,   0=don't zero-init
+	dd 0x100030	; entry address
 
+	; we don't ask for video mode really as it's too unreliable
+	; but here's it zeroed-out anyway
+	dd 0 ; videomode 0=linear 1=ega text
+	dd 0 ; width  0=no pref
+	dd 0 ; height 0=no pref
+	dd 0 ; depth  0=no pref
 start:
 	; Setup stack
 	mov ebp, stack_top