*very noob question* What is a very simple printf command?

[feare56]

Ok I am pretty much a noob at OS dev but am a good c/++ programmer. I am also a visual kinda guy so I can learn from the most basic of code. I plan to make a hybrid monolithic-micro kernel so all the drivers and the filesystem. I am just asking for a basic one where it simply displays a character so I can test kernel and boot loader

[Love4Boobies]

Have you checked the wiki? We have articles that explain this sort of stuff and the tutorials even offer some rudimentary examples.

[feare56]

Oh I haven't seen that on the wiki thank you

[andyharglesis]

If you want to print to the screen in the bootloader use BIOS int 0x10h(assuming this is x86-architecture).

Printf in C is absolutely nothing like writing to video memory, or more directly interfacing with hardware.

Printf is a written command to parse syntax into string data for a text terminal, or I/O stream console, which doesn't even exist on a bare-system unless you make one.

There's plenty of tutorials on printing to the screen using "Hello World" in x86 Real Mode 16-bit bootloaders, and they're not really that hard.

Using an x86 virtual machine you can test it pretty instantly as well, if in fear of using real hardware directly to execute it(and for other reasons).

[feare56]

Thank you that helped a lot

[feare56]

Windows and Mac and numerous others have that hybrid. And I think a monolithic is too much and a micro kernel is not enough

[ACcurrent]

Read barebones

[JamesParsons]

Heres something

Code: Select all

// note this example will always write to the top
// line of the screen
void write_string( int colour, const char *string )
{
    volatile char *video = (volatile char*)0xB8000;
    while( *string != 0 )
    {
        *video++ = *string++;
        *video++ = colour;
    }
}

this was on the wiki Printing To Screen

[feare56]

Thank you