My Kernel v0.1.0
Macros
Memory Constants - x86
Kernel functions and structures » Memory Constants | Kernel functions and structures » Arch - x86

Constants related to the kernel's memory layout on the x86 architecture. More...

Collaboration diagram for Memory Constants - x86:

Macros

#define PAGE_SHIFT   12
 Number of bits to shift one bit left to get the size of a page.
 
#define PAGE_SIZE   (1 << PAGE_SHIFT)
 The size of a single page.
 
#define PHYSICAL_MEMORY_START   0x500
 First usable physical address. More...
 
#define PHYSICAL_MEMORY_END   0xFFFFFFFF
 Last usable physical address.
 
#define ADDRESS_SPACE_SIZE   (0x100000000UL)
 The size of the virtual address space 32-bit address bus -> 4GiB of addressable memory.
 

Detailed Description

Macro Definition Documentation

◆ PHYSICAL_MEMORY_START

#define PHYSICAL_MEMORY_START   0x500

The first 256KiB of physical memory contain the BIOS' code and real mode interrupt vectors table. It may still be used when switching back to real mode so we should not overwrite it.