1 /* 2 ** Copyright 2001-2002, Travis Geiselbrecht. All rights reserved. 3 ** Distributed under the terms of the NewOS License. 4 */ 5 #ifndef _KERNEL_ARCH_x86_KERNEL_H 6 #define _KERNEL_ARCH_x86_KERNEL_H 7 8 #ifndef _ASSEMBLER 9 # include <arch/cpu.h> 10 #endif 11 12 // memory layout 13 #define KERNEL_BASE 0x80000000 14 #define KERNEL_SIZE 0x80000000 15 #define KERNEL_TOP (KERNEL_BASE + (KERNEL_SIZE - 1)) 16 17 /* 18 ** User space layout is a little special: 19 ** The user space does not completely cover the space not covered by the kernel. 20 ** This is accomplished by starting user space at 1Mb and running to 64kb short of kernel space. 21 ** The lower 1Mb reserved spot makes it easy to find null pointer references and guarantees a 22 ** region wont be placed there. The 64kb region assures a user space thread cannot pass 23 ** a buffer into the kernel as part of a syscall that would cross into kernel space. 24 */ 25 #define USER_BASE 0x100000 26 #define USER_SIZE (0x80000000 - (0x10000 + 0x100000)) 27 #define USER_TOP (USER_BASE + USER_SIZE) 28 29 #define USER_STACK_REGION 0x70000000 30 #define USER_STACK_REGION_SIZE (USER_TOP - USER_STACK_REGION) 31 32 #endif /* _KERNEL_ARCH_x86_KERNEL_H */ 33