osdev

I am currently following this workbook on build an operating system. My intention is to write a 64-bit kernel. I have got as far as loading the "kernel" code and writing individual characters to the frame buffer while in text mode. My problem appears when I add a level of indirection to writing a single character to the frame buffer by wrapping the code in a function. It would appear that the char value passed into the function is being corrupted in some way. I have three files: bootloader.asm ; bootloader.asm [org 0x7c00] KERNEL_OFFSET equ 0x1000 mov bp, 0x9000 mov sp, bp ; load the kernel

How do I write a .bin file to be in the first sector of a floppy disk/virtual floppy disk/floppy image? I'm trying to boot a simple 512-byte bootloader. The size on everywhere says "512 bytes" so I should be good already. Additional Information: The bootloader simply displays a string, and I'm learning simple assembly. Some of the work is made in Windows and some in Ubuntu 14.04 (Trusty Tahr) (if this matters). It doesn't boot even though it has the bootloader sign. If you are on Linux you can do it with DD utility. There is a version of DD for Microsoft Windows as well. General DD usage If

I am developing a kernel in C and created something to print on screen on video memory. I expected that the first byte in video memory would be the character to print and the second byte tells the color. But my program has something different but it works!! It is very unexpected and unusual. My kernel code - #define VIDEO_MEM 0xb8000 void write_string( int colour, const unsigned char *string ); void main() { unsigned char *vid = (unsigned char*) VIDEO_MEM; int i=0; for (i = 0; i < 2000; i++) { *vid = ' '; *(vid+2) = 0x1f; vid += 2; } write_string(0x1f,"The Kernel has been loaded successfully!!