The Place to Start for Operating System Developers
http://f.osdev.org/
There's also prebuilt toolchains available for some platforms at the bottom of the cross-compiler page. If you want help building a cross toolchain, you can post a topic and ask for help (I wouldn't know if you already did this), or show up in #osdev on freenode IRC and see if people can't help you out.thehardcoreOS wrote:Hey sortie, I am not using gcc cross-compiler because it refused to build, I was getting some strange errors while building it...
It is a real pain to make it work since you need to manually move and install all those binutils.
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init(mboot->framebuffer_addr, mboot->framebuffer_pitch, mboot->framebuffer_width, mboot->framebuffer_height, mboot->framebuffer_bpp, 1024, 768);
That doesn't switch video mode (and I'd assume it only configures the kernel to suit whatever video mode GRUB happened to set); and the values being passed look a little redundant to me (it has width and height from multi-boot that should be correct even if GRUB couldn't find 1024*768 and chose something else, and then the "1024, 768" at the end that looks both unnecessary and potentially wrong).ch3ll0v3k wrote:Can you please share the implementation of this:
I cant, switch video mode.Code: Select all
init(mboot->framebuffer_addr, mboot->framebuffer_pitch, mboot->framebuffer_width, mboot->framebuffer_height, mboot->framebuffer_bpp, 1024, 768);
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intV86(0x10, "ax,cx,es:di", 0x4F01, modes[i], 0, modeInfo);
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; // MODE RESOLUTION BITS PER PIXEL MAXIMUM COLORS
; // 0x0100 640x480 4 16
; // 0x0101 640x480 8 256
; // 0x0102 800x600 4 16
; // 0x0103 800x600 8 256
; // 0x010D 320x200 15 32k
; // 0x010E 320x200 16 64k
; // 0x010F 320x200 24/32* 16m
; // 0x0110 640x480 15 32k
; // 0x0111 640x480 16 64k
; // 0x0112 640x480 24/32* 16m
; // 0x0113 800x600 15 32k
; // 0x0114 800x600 16 64k
; // 0x0115 800x600 24/32* 16m
; // 0x0116 1024x768 15 32k
; // 0x0117 1024x768 16 64k
; // 0x0118 1024x768 24/32* 16m
loader:
mov ax, 0x4F02
mov bx, 0x4100
int 0x10
cmp ax, 0x004F
jne error:
cli ; Clear interrupt flag [IF = 0]; 0xFA
mov esp, kernel_stack ; set stack pointer
push ebx ; info (ram-size, ... ) [multiboot structure]
push eax ; MAGIC
call kernel_main ; controll to kernel_main(); in kernelc.c
hlt ; HLT Enter halt state 0xF4
I have no idea what that is (the name "intV86" implies that it might be a function that uses virtual80x86 mode to execute an interrupt but I've seen misleading/wrong names too often to make assumptions like that and it could be switching back to real mode instead).ch3ll0v3k wrote:I see sometimes people talk about this function:so thay can make call to BIOS in real mode to switch or get info.Code: Select all
intV86(0x10, "ax,cx,es:di", 0x4F01, modes[i], 0, modeInfo);
It's part of something that you'd need to write or copy or steal.ch3ll0v3k wrote:Do i need implement this function or is it part of something that i can just use?
Then you should probably let GRUB choose a video mode for you (by telling GRUB what you want in you're kernel's "multiboot header"), so you don't need to deal with any assembly.ch3ll0v3k wrote:I use GRUB and my system runs direct in protected mode. My skils in assembly is very basic.
That's because the BIOS functions (and the BIOS "IVT/Interrupt Vector Table") are designed for real mode and you aren't in real mode.ch3ll0v3k wrote:If i execute assembly instruction before i clear all interruprs, my system kips rebooting.
I use this,
ch3ll0v3k wrote:Code: Select all
; // MODE RESOLUTION BITS PER PIXEL MAXIMUM COLORS ; // 0x0100 640x480 4 16 ; // 0x0101 640x480 8 256 ; // 0x0102 800x600 4 16 ; // 0x0103 800x600 8 256 ; // 0x010D 320x200 15 32k ; // 0x010E 320x200 16 64k ; // 0x010F 320x200 24/32* 16m ; // 0x0110 640x480 15 32k ; // 0x0111 640x480 16 64k ; // 0x0112 640x480 24/32* 16m ; // 0x0113 800x600 15 32k ; // 0x0114 800x600 16 64k ; // 0x0115 800x600 24/32* 16m ; // 0x0116 1024x768 15 32k ; // 0x0117 1024x768 16 64k ; // 0x0118 1024x768 24/32* 16m[/quote] Note that "fixed mode numbers" (what you've listed here) were deprecated by VBE2.0 in 1994 and should not be relied on (unless you know the video card's ROM doesn't support VBE2.0 but does support VBE1.x). Cheers, Brendan
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[BITS 32]
align 4
; // ======================================================================
; // http://www.osdever.net/bkerndev/Docs/basickernel.htm
; // https://www.gnu.org/software/grub/manual/multiboot/multiboot.html#Boot-information-format
MBALIGN equ 1<<0 ; // align loaded modules on page boundaries
MEMINFO equ 1<<1 ; // provide memory map
VIDMOD equ 1<<2 ; // information about the video mode table must be available to the kernel.
;ELF_OR equ 1<<16 ; // must be providet if kernel is not ELF
FLAGS equ MBALIGN | MEMINFO | VIDMOD
MAGIC equ 0x1BADB002 ; // 'magic number' lets bootloader find the header
CHECKSUM equ -(MAGIC + FLAGS) ; // checksum of above, to prove we are multiboot
section .multiboot
dd MAGIC
dd FLAGS
dd CHECKSUM
dd 0 ; 12 u32 header_addr if flags[16] is set
dd 0 ; 16 u32 load_addr if flags[16] is set
dd 0 ; 20 u32 load_end_addr if flags[16] is set
dd 0 ; 24 u32 bss_end_addr if flags[16] is set
dd 0 ; 28 u32 entry_addr if flags[16] is set
dd 0 ; 32 u32 mode_type if flags[2] is set
dd 800 ; 36 u32 width if flags[2] is set
dd 600 ; 40 u32 height if flags[2] is set
dd 32 ; 44 u32 depth if flags[2] is set
;//======================================================================
global loader
extern kernel_main
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dd 1 // 1== is text mode
dd 80 // == width in chars
dd 24 // == height in chars
dd 0 // if mode "1" then this is "0"
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dd 0 // 0== is graphic mode
dd 1024 // == width in PX
dd 768 // == height in PX
dd 32 // depth