WebSVN – HelenOS – Blame – /trunk/boot/arch/arm32/loader/mm.h

Rev	Author	Line No.	Line
2468	jermar	1	/*
		2	* Copyright (c) 2007 Pavel Jancik
		3	* Copyright (c) 2007 Michal Kebrt
		4	* All rights reserved.
		5	*
		6	* Redistribution and use in source and binary forms, with or without
		7	* modification, are permitted provided that the following conditions
		8	* are met:
		9	*
		10	* - Redistributions of source code must retain the above copyright
		11	* notice, this list of conditions and the following disclaimer.
		12	* - Redistributions in binary form must reproduce the above copyright
		13	* notice, this list of conditions and the following disclaimer in the
		14	* documentation and/or other materials provided with the distribution.
		15	* - The name of the author may not be used to endorse or promote products
		16	* derived from this software without specific prior written permission.
		17	*
		18	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
		19	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
		20	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
		21	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
		22	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
		23	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
		24	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
		25	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
		26	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
		27	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
		28	*/
		29
		30
		31	/** @addtogroup arm32boot
		32	* @{
		33	*/
		34	/** @file
		35	* @brief Memory management used while booting the kernel.
		36	*
		37	* So called "section" paging is used while booting the kernel. The term
		38	* "section" comes from the ARM architecture specification and stands for the
		39	* following: one-level paging, 1MB sized pages, 4096 entries in the page
		40	* table.
		41	*/
		42
		43
		44	#ifndef BOOT_arm32__MM_H
		45	#define BOOT_arm32__MM_H
		46
		47
		48	#ifndef __ASM__
		49	#include "types.h"
		50	#endif
		51
		52
		53	/** Frame width. */
		54	#define FRAME_WIDTH 20
		55
		56	/** Frame size. */
		57	#define FRAME_SIZE (1 << FRAME_WIDTH)
		58
		59	/** Page size in 2-level paging which is switched on later after the kernel
		60	* initialization.
		61	*/
		62	#define KERNEL_PAGE_SIZE (1 << 12)
		63
		64
		65	#ifndef __ASM__
		66	/** Converts kernel address to physical address. */
		67	# define KA2PA(x) (((uintptr_t) (x)) - 0x80000000)
		68	/** Converts physical address to kernel address. */
		69	# define PA2KA(x) (((uintptr_t) (x)) + 0x80000000)
		70	#else
		71	# define KA2PA(x) ((x) - 0x80000000)
		72	# define PA2KA(x) ((x) + 0x80000000)
		73	#endif
		74
		75
		76	/** Number of entries in PTL0. */
		77	#define PTL0_ENTRIES (1 << 12) /* 4096 */
		78
		79	/** Size of an entry in PTL0. */
		80	#define PTL0_ENTRY_SIZE 4
		81
		82	/** Returns number of frame the address belongs to. */
		83	#define ADDR2PFN(addr) (((uintptr_t) (addr)) >> FRAME_WIDTH)
		84
		85	/** Describes "section" page table entry (one-level paging with 1MB sized pages). */
		86	#define PTE_DESCRIPTOR_SECTION 0x2
		87
		88	/** Page table access rights: user - no access, kernel - read/write. */
		89	#define PTE_AP_USER_NO_KERNEL_RW 0x1
		90
		91
		92	#ifndef __ASM__
		93
		94
		95	/** Page table level 0 entry - "section" format is used (one-level paging, 1MB
		96	* sized pages). Used only while booting the kernel.
		97	*/
		98	typedef struct {
		99	unsigned descriptor_type : 2;
		100	unsigned bufferable : 1;
		101	unsigned cacheable : 1;
		102	unsigned impl_specific : 1;
		103	unsigned domain : 4;
		104	unsigned should_be_zero_1 : 1;
		105	unsigned access_permission : 2;
		106	unsigned should_be_zero_2 : 8;
		107	unsigned section_base_addr : 12;
		108	} __attribute__ ((packed)) pte_level0_section_t;
		109
		110
		111	/** Page table that holds 1:1 virtual to physical mapping used while booting the
		112	* kernel.
		113	*/
		114	extern pte_level0_section_t page_table[PTL0_ENTRIES];
		115
		116	extern void mmu_start(void);
		117
		118
		119	/** Enables paging. */
		120	static inline void enable_paging()
		121	{
		122	/* c3 - each two bits controls access to the one of domains (16)
		123	* 0b01 - behave as a client (user) of a domain
		124	*/
		125	asm volatile (
		126	/* behave as a client of domains */
		127	"ldr r0, =0x55555555\n"
		128	"mcr p15, 0, r0, c3, c0, 0\n"
		129
		130	/* current settings */
		131	"mrc p15, 0, r0, c1, c0, 0\n"
		132
		133	/* mask to enable paging */
		134	"ldr r1, =0x00000001\n"
		135	"orr r0, r0, r1\n"
		136
		137	/* store settings */
		138	"mcr p15, 0, r0, c1, c0, 0\n"
		139	:
		140	:
		141	: "r0", "r1"
		142	);
		143	}
		144
		145
		146	/** Sets the address of level 0 page table to CP15 register 2.
		147	*
		148	* @param pt Address of a page table to set.
		149	*/
		150	static inline void set_ptl0_address(pte_level0_section_t* pt)
		151	{
		152	asm volatile (
		153	"mcr p15, 0, %0, c2, c0, 0\n"
		154	:
		155	: "r" (pt)
		156	);
		157	}
		158
		159
		160	#endif
		161
		162	#endif
		163
		164	/** @}
		165	*/
		166

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(root)/trunk/boot/arch/arm32/loader/mm.h – Rev 2473