0xE0000000 (3.5 GB) -- Drivers 0xC0001000 -- Kernel Page Table 0xC0000200 -- GDT 0xC0000000 (3 GB) -- IDT ----------------------- End of user space, start of kernel space --------------------- 0x00000000 (0 GB) -- User space Format of kernel.sys: Inital System (Multiboot header embedded into unused gdt slots, is replaced later) Text Data Start up code (Replaced by bss) 0x0000 - IDT 0x0200 - GDT (Multiboot header inside unused descriptors, cleared by start up code) 0x1000 - Page Table for 0xC0400000 - 0xC0800000 0x2000 - Text & Data