xref: /openbmc/u-boot/arch/x86/include/asm/cpu.h (revision b97cd681)
1 /*
2  * Copyright (c) 2014 The Chromium OS Authors.
3  *
4  * SPDX-License-Identifier:	GPL-2.0+
5  */
6 
7 #ifndef __X86_CPU_H
8 #define __X86_CPU_H
9 
10  /**
11  * cpu_enable_paging_pae() - Enable PAE-paging
12  *
13  * @pdpt:	Value to set in cr3 (PDPT or PML4T)
14  */
15 void cpu_enable_paging_pae(ulong cr3);
16 
17 /**
18  * cpu_disable_paging_pae() - Disable paging and PAE
19  */
20 void cpu_disable_paging_pae(void);
21 
22 /**
23  * cpu_has_64bit() - Check if the CPU has 64-bit support
24  *
25  * @return 1 if this CPU supports long mode (64-bit), 0 if not
26  */
27 int cpu_has_64bit(void);
28 
29 /**
30  * cpu_call64() - Jump to a 64-bit Linux kernel (internal function)
31  *
32  * The kernel is uncompressed and the 64-bit entry point is expected to be
33  * at @target.
34  *
35  * This function is used internally - see cpu_jump_to_64bit() for a more
36  * useful function.
37  *
38  * @pgtable:	Address of 24KB area containing the page table
39  * @setup_base:	Pointer to the setup.bin information for the kernel
40  * @target:	Pointer to the start of the kernel image
41  */
42 void cpu_call64(ulong pgtable, ulong setup_base, ulong target);
43 
44 /**
45  * cpu_jump_to_64bit() - Jump to a 64-bit Linux kernel
46  *
47  * The kernel is uncompressed and the 64-bit entry point is expected to be
48  * at @target.
49  *
50  * @setup_base:	Pointer to the setup.bin information for the kernel
51  * @target:	Pointer to the start of the kernel image
52  */
53 int cpu_jump_to_64bit(ulong setup_base, ulong target);
54 
55 #endif
56