WebSVN – HelenOS – Diff – /trunk/kernel/arch/arm32/src/userspace.c


/*
 * Copyright (c) 2007 Petr Stepan, Pavel Jancik
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
 
/** @addtogroup arm32
 * @{
 */
/** @file
 *  @brief Userspace switch.
 */
 
#include <userspace.h>
 
/** Struct for holding all general purpose registers.
 *  
 *  Used to set registers when going to userspace.
 */
typedef struct {
    uint32_t r0;
    uint32_t r1;
    uint32_t r2;
    uint32_t r3;
    uint32_t r4;
    uint32_t r5;
    uint32_t r6;
    uint32_t r7;
    uint32_t r8;
    uint32_t r9;
    uint32_t r10;
    uint32_t r11;
    uint32_t r12;
    uint32_t sp;
    uint32_t lr;
    uint32_t pc;
} ustate_t;
 
/** Changes processor mode and jumps to the address specified in the first
 * parameter.
 *
 *  @param kernel_uarg   Userspace settings (entry point, stack, ...).
 */
void userspace(uspace_arg_t *kernel_uarg)
{
    volatile ustate_t ustate;
 
    /* set first parameter */
    ustate.r0 = (uintptr_t) kernel_uarg->uspace_uarg;
 
    /* clear other registers */
    ustate.r1 = ustate.r2  = ustate.r3  = ustate.r4  = ustate.r5 =
        ustate.r6  = ustate.r7  = ustate.r8  = ustate.r9 = ustate.r10 =
        ustate.r11 = ustate.r12 = ustate.lr = 0;
 
    /* set user stack */
    ustate.sp = ((uint32_t)kernel_uarg->uspace_stack) + PAGE_SIZE;
 
    /* set where uspace execution starts */
    ustate.pc = (uintptr_t) kernel_uarg->uspace_entry;
 
    /* status register in user mode */
    ipl_t user_mode = current_status_reg_read() &
        (~STATUS_REG_MODE_MASK | USER_MODE);
 
    /* set user mode, set registers, jump */
    asm volatile (
        "mov r0, %0         \n"
        "msr spsr_c, %1         \n"
        "ldmfd r0!, {r0-r12, sp, lr}^   \n"
        "ldmfd r0!, {pc}^\n"
        :
        : "r" (&ustate), "r" (user_mode)
        : "r0", "r1"
    );
 
    /* unreachable */
    while(1)
        ;
}
 
/** @}
 */
 

Rev 2464	Rev 2465
1	/*	1	/*
2	* Copyright (c) 2007 Petr Stepan, Pavel Jancik	2	* Copyright (c) 2007 Petr Stepan, Pavel Jancik
3	* All rights reserved.	3	* All rights reserved.
4	*	4	*
5	* Redistribution and use in source and binary forms, with or without	5	* Redistribution and use in source and binary forms, with or without
6	* modification, are permitted provided that the following conditions	6	* modification, are permitted provided that the following conditions
7	* are met:	7	* are met:
8	*	8	*
9	* - Redistributions of source code must retain the above copyright	9	* - Redistributions of source code must retain the above copyright
10	* notice, this list of conditions and the following disclaimer.	10	* notice, this list of conditions and the following disclaimer.
11	* - Redistributions in binary form must reproduce the above copyright	11	* - Redistributions in binary form must reproduce the above copyright
12	* notice, this list of conditions and the following disclaimer in the	12	* notice, this list of conditions and the following disclaimer in the
13	* documentation and/or other materials provided with the distribution.	13	* documentation and/or other materials provided with the distribution.
14	* - The name of the author may not be used to endorse or promote products	14	* - The name of the author may not be used to endorse or promote products
15	* derived from this software without specific prior written permission.	15	* derived from this software without specific prior written permission.
16	*	16	*
17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR	17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES	18	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.	19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,	20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT	21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,	22	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY	23	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT	24	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF	25	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.	26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27	*/	27	*/
28		28
29	/** @addtogroup arm32	29	/** @addtogroup arm32
30	* @{	30	* @{
31	*/	31	*/
32	/** @file	32	/** @file
33	* @brief Userspace switch.	33	* @brief Userspace switch.
34	*/	34	*/
35		35
36	#include <userspace.h>	36	#include <userspace.h>
37		37
38	/** Struct for holding all general purpose registers.	38	/** Struct for holding all general purpose registers.
39	*	39	*
40	* Used to set registers when going to userspace.	40	* Used to set registers when going to userspace.
41	*/	41	*/
42	typedef struct {	42	typedef struct {
43	uint32_t r0;	43	uint32_t r0;
44	uint32_t r1;	44	uint32_t r1;
45	uint32_t r2;	45	uint32_t r2;
46	uint32_t r3;	46	uint32_t r3;
47	uint32_t r4;	47	uint32_t r4;
48	uint32_t r5;	48	uint32_t r5;
49	uint32_t r6;	49	uint32_t r6;
50	uint32_t r7;	50	uint32_t r7;
51	uint32_t r8;	51	uint32_t r8;
52	uint32_t r9;	52	uint32_t r9;
53	uint32_t r10;	53	uint32_t r10;
54	uint32_t r11;	54	uint32_t r11;
55	uint32_t r12;	55	uint32_t r12;
56	uint32_t sp;	56	uint32_t sp;
57	uint32_t lr;	57	uint32_t lr;
58	uint32_t pc;	58	uint32_t pc;
59	} ustate_t;	59	} ustate_t;
60		60
61	/** Changes processor mode and jumps to the address specified in the first	61	/** Changes processor mode and jumps to the address specified in the first
62	* parameter.	62	* parameter.
63	*	63	*
64	* @param kernel_uarg Userspace settings (entry point, stack, ...).	64	* @param kernel_uarg Userspace settings (entry point, stack, ...).
65	*/	65	*/
66	void userspace(uspace_arg_t *kernel_uarg)	66	void userspace(uspace_arg_t *kernel_uarg)
67	{	67	{
68	volatile ustate_t ustate;	68	volatile ustate_t ustate;
69		69
70	/* set first parameter */	70	/* set first parameter */
71	ustate.r0 = (uintptr_t) kernel_uarg->uspace_uarg;	71	ustate.r0 = (uintptr_t) kernel_uarg->uspace_uarg;
72		72
73	/* clear other registers */	73	/* clear other registers */
74	ustate.r1 = ustate.r2 = ustate.r3 = ustate.r4 = ustate.r5 =	74	ustate.r1 = ustate.r2 = ustate.r3 = ustate.r4 = ustate.r5 =
75	ustate.r6 = ustate.r7 = ustate.r8 = ustate.r9 = ustate.r10 =	75	ustate.r6 = ustate.r7 = ustate.r8 = ustate.r9 = ustate.r10 =
76	ustate.r11 = ustate.r12 = ustate.lr = 0;	76	ustate.r11 = ustate.r12 = ustate.lr = 0;
77		77
78	/* set user stack */	78	/* set user stack */
79	ustate.sp = ((uint32_t)kernel_uarg->uspace_stack) + PAGE_SIZE;	79	ustate.sp = ((uint32_t)kernel_uarg->uspace_stack) + PAGE_SIZE;
80		80
81	/* set where uspace execution starts */	81	/* set where uspace execution starts */
82	ustate.pc = (uintptr_t) kernel_uarg->uspace_entry;	82	ustate.pc = (uintptr_t) kernel_uarg->uspace_entry;
83		83
84	/* status register in user mode */	84	/* status register in user mode */
85	ipl_t user_mode = current_status_reg_read() &	85	ipl_t user_mode = current_status_reg_read() &
86	(~STATUS_REG_MODE_MASK \| USER_MODE);	86	(~STATUS_REG_MODE_MASK \| USER_MODE);
87		87
88	/* set user mode, set registers, jump */	88	/* set user mode, set registers, jump */
89	asm volatile (	89	asm volatile (
90	"mov r0, %0 \n"	90	"mov r0, %0 \n"
91	"msr spsr_c, %1 \n"	91	"msr spsr_c, %1 \n"
92	"ldmfd r0!, {r0-r12, sp, lr}^ \n"	92	"ldmfd r0!, {r0-r12, sp, lr}^ \n"
93	"ldmfd r0!, {pc}^\n"	93	"ldmfd r0!, {pc}^\n"
94	:	94	:
95	: "r" (&ustate), "r" (user_mode)	95	: "r" (&ustate), "r" (user_mode)
96	: "r0", "r1"	96	: "r0", "r1"
97	);	97	);
98		98
99	/* unreachable */	99	/* unreachable */
100	while(1)	100	while(1)
101	;	101	;
102	}	102	}
103		103
104	/** @}	104	/** @}
105	*/	105	*/
106		106

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(root)/trunk/kernel/arch/arm32/src/userspace.c – Rev 2464 → 2465