get_framebuffer

On many architectures, the bootloader or kernel can create a naive framebuffer using a platform-specific method. This framebuffer can be used to render from userspace, if a better hardware driver is not available on the platform.

Parameters

• a should contain a mapped, writable, user-space address, to which information about the framebuffer will be written.

Returns

This system call returns three things:

• A status code
• A handle to a MemoryObject containing the framebuffer, if successful
• Information about the framebuffer, if successful, written into the address in a

The status codes used are:

• 0 means that the system call was successful
• 1 means that the calling task does not have the correct capability
• 2 means that a does not contain a valid address for the kernel to write to
• 3 means that the kernel did not create the framebuffer

The information written back to the address in a has the following structure:

#![allow(unused)]
fn main() {
#[repr(C)]
struct FramebufferInfo {
    width: u16,
    height: u16,
    stride: u16,
    /// 0 = RGB32
    /// 1 = BGR32
    pixel_format: u8,
}
}

Capabilities needed

Tasks need the GetKernelFramebuffer capability to use this system call.