| 30,12 → 30,16 |
|---|
| * @{ |
| */ |
| /** @file |
| * @brief Userspace. |
| * @brief Userspace switch. |
| */ |
| |
| #include <userspace.h> |
| |
| /** Struct to hold general purpose register values */ |
| |
| /** Struct for holding all general purpose registers. |
| * |
| * Used to set registers when going to userspace. |
| */ |
| typedef struct { |
| uint32_t r0; |
| uint32_t r1; |
| 74,37 → 78,25 |
|---|
| ustate.r9 = ustate.r10 = ustate.r11 = ustate.r12 = |
| ustate.lr = 0; |
| |
| //set user stack |
| ustate.sp = ((uint32_t)kernel_uarg->uspace_stack) + |
| PAGE_SIZE - sizeof(void*); |
| // set user stack |
| ustate.sp = ((uint32_t)kernel_uarg->uspace_stack) + PAGE_SIZE; |
| |
| //set where uspace execution starts |
| // set where uspace execution starts |
| ustate.pc = (uintptr_t) kernel_uarg->uspace_entry; |
| |
| //status register in user mode |
| ipl_t cpsr = current_status_reg_read(); |
| cpsr &= ~STATUS_REG_MODE_MASK | USER_MODE; |
| // status register in user mode |
| ipl_t user_mode = current_status_reg_read() & (~STATUS_REG_MODE_MASK | USER_MODE); |
| |
| ipl_t tmpsr = (cpsr & ~STATUS_REG_MODE_MASK) | SUPERVISOR_MODE; |
| |
| // set user mode, set registers, jump |
| asm __volatile__ ( |
| // save pointer into ustate struct |
| "mov r0, %0 \n" |
| // save cspr |
| "mov r1, %1 \n" |
| // change mode into any exception mode |
| "msr cpsr_c, %2 \n" |
| // set saved cpsr |
| "msr spsr_c, r1 \n" |
| |
| "mov sp, r0 \n" |
| // replace almost all registers |
| "ldmfd sp!, {r0-r12, sp, lr}^\n" |
| //jump to the usermode |
| "ldmfd sp!, {pc}^" |
| : // no output |
| : "r"(&ustate), "r"(cpsr), "r"(tmpsr) // |
| : "r0","r1" |
| "mov r0, %0 \n" |
| "msr spsr_c, %1 \n" |
| "ldmfd r0!, {r0-r12, sp, lr}^ \n" |
| "ldmfd r0!, {pc}^" |
| |
| : |
| : "r"(&ustate), "r"(user_mode) |
| : "r0", "r1" |
| ); |
| |
| // unreachable |