Subversion Repositories HelenOS

Rev

Rev 2413 | Rev 2477 | Go to most recent revision | Show entire file | Ignore whitespace | Details | Blame | Last modification | View Log | RSS feed

Rev 2413 Rev 2464
Line 33... Line 33...
33 
 *  @brief Userspace switch.
 33 
 *  @brief Userspace switch.
34 
 */
 34 
 */
35 
 
 35 
 
36 
#include <userspace.h>
 36 
#include <userspace.h>
37 
 
 37 
 
38 
 
 - 
 
39 
/** Struct for holding all general purpose registers.
 38 
/** Struct for holding all general purpose registers.
40 
 *  
 39 
 *  
41 
 *  Used to set registers when going to userspace.
 40 
 *  Used to set registers when going to userspace.
42 
 */
 41 
 */
43 
typedef struct {
 42 
typedef struct {
Line 57... Line 56...
57 
    uint32_t sp;
 56 
    uint32_t sp;
58 
    uint32_t lr;
 57 
    uint32_t lr;
59 
    uint32_t pc;
 58 
    uint32_t pc;
60 
} ustate_t;
 59 
} ustate_t;
61 
 
 60 
 
62 
 
 - 
 
63 
/** Changes processor mode and jumps to the address specified in the first parameter.
 61 
/** Changes processor mode and jumps to the address specified in the first
- 
 
 62 
 * parameter.
64 
 *
 63 
 *
65 
 *  @param kernel_uarg   Userspace settings (entry point, stack, ...).
 64 
 *  @param kernel_uarg   Userspace settings (entry point, stack, ...).
66 
 */
 65 
 */
67 
void userspace(uspace_arg_t *kernel_uarg)
 66 
void userspace(uspace_arg_t *kernel_uarg)
68 
{
 67 
{
69 
 
 - 
 
70 
    volatile ustate_t ustate;
 68 
    volatile ustate_t ustate;
71 
 
 69 
 
72 
    // set first parameter
 70 
    /* set first parameter */
73 
    ustate.r0 = (uintptr_t) kernel_uarg->uspace_uarg;
 71 
    ustate.r0 = (uintptr_t) kernel_uarg->uspace_uarg;
74 
 
 72 
 
75 
    // clear other registers
 73 
    /* clear other registers */
76 
    ustate.r1 = ustate.r2  = ustate.r3  = ustate.r4  =
 74 
    ustate.r1 = ustate.r2  = ustate.r3  = ustate.r4  = ustate.r5 =
77 
        ustate.r5 = ustate.r6  = ustate.r7  = ustate.r8  =
 75 
        ustate.r6  = ustate.r7  = ustate.r8  = ustate.r9 = ustate.r10 =
78 
        ustate.r9 = ustate.r10 = ustate.r11 = ustate.r12 =
 76 
        ustate.r11 = ustate.r12 = ustate.lr = 0;
79 
        ustate.lr = 0;
 - 
 
80 
 
 77 
 
81 
    // set user stack
 78 
    /* set user stack */
82 
    ustate.sp = ((uint32_t)kernel_uarg->uspace_stack) + PAGE_SIZE;
 79 
    ustate.sp = ((uint32_t)kernel_uarg->uspace_stack) + PAGE_SIZE;
83 
 
 80 
 
84 
    // set where uspace execution starts
 81 
    /* set where uspace execution starts */
85 
    ustate.pc = (uintptr_t) kernel_uarg->uspace_entry;
 82 
    ustate.pc = (uintptr_t) kernel_uarg->uspace_entry;
86 
 
 83 
 
87 
    // status register in user mode
 84 
    /* status register in user mode */
88 
    ipl_t user_mode = current_status_reg_read() & (~STATUS_REG_MODE_MASK | USER_MODE);
 85 
    ipl_t user_mode = current_status_reg_read() &
- 
 
 86 
        (~STATUS_REG_MODE_MASK | USER_MODE);
89 
 
 87 
 
90 
    // set user mode, set registers, jump
 88 
    /* set user mode, set registers, jump */
91 
    asm __volatile__ (
 89 
    asm volatile (
92 
        "mov r0, %0         \n"    
 90 
        "mov r0, %0         \n"
93 
        "msr spsr_c, %1     \n"
 91 
        "msr spsr_c, %1         \n"
94 
        "ldmfd r0!, {r0-r12, sp, lr}^  \n"
 92 
        "ldmfd r0!, {r0-r12, sp, lr}^   \n"
95 
        "ldmfd r0!, {pc}^"
 93 
        "ldmfd r0!, {pc}^\n"
96 
       
 - 
 
97 
        :
 94 
        :
98 
        : "r"(&ustate), "r"(user_mode)
 95 
        : "r" (&ustate), "r" (user_mode)
99 
        : "r0", "r1"
 96 
        : "r0", "r1"
100 
    );
 97 
    );
101 
 
 98 
 
102 
    // unreachable
 99 
    /* unreachable */
103 
    while(1) ;
 100 
    while(1)
- 
 
 101 
        ;
104 
}
 102 
}
105 
 
 103 
 
106 
 
 - 
 
107 
/** @}
 104 
/** @}
108 
 */
 105 
 */