diff options
Diffstat (limited to 'cpukit/score/cpu/nios2/cpu_asm.S')
| -rw-r--r-- | cpukit/score/cpu/nios2/cpu_asm.S | 388 |
1 files changed, 0 insertions, 388 deletions
diff --git a/cpukit/score/cpu/nios2/cpu_asm.S b/cpukit/score/cpu/nios2/cpu_asm.S deleted file mode 100644 index 2244430703..0000000000 --- a/cpukit/score/cpu/nios2/cpu_asm.S +++ /dev/null @@ -1,388 +0,0 @@ -/* - * $Id$ - * - * This file contains all assembly code for the - * NIOS2 implementation of RTEMS. - * - * Copyright (c) 2006 Kolja Waschk (rtemsdev/ixo.de) - * - * Derived from no_cpu/cpu_asm.S, copyright (c) 1989-1999, - * On-Line Applications Research Corporation (OAR). - * - * The license and distribution terms for this file may be - * found in the file LICENSE in this distribution or at - * http://www.rtems.com/license/LICENSE. - * - */ - -#include <rtems/asm.h> -#include <rtems/score/cpu_asm.h> - - .set noat - - .extern _ISR_Nest_level - .extern _ISR_Signals_to_thread_executing - .extern _Context_Switch_necessary - .extern _Thread_Dispatch - .extern _Thread_Dispatch_disable_level - -/* ===================================================================== */ - -/* - * void _CPU_Context_switch( run_context, heir_context ) - * void _CPU_Context_restore( run_context, heir_context ) - * - * This routine performs a normal non-FP context switch. - */ - - .globl _CPU_Context_switch - -_CPU_Context_switch: - - rdctl r6, status - stw r16, 0(r4) - stw r17, 4(r4) - stw r18, 8(r4) - stw r19, 12(r4) - stw r20, 16(r4) - stw r21, 20(r4) - stw r22, 24(r4) - stw r23, 28(r4) - stw gp, 32(r4) - stw fp, 36(r4) - stw sp, 40(r4) - stw ra, 44(r4) - /* r6 saved status */ - stw r6, 48(r4) - -_CPU_Context_switch_restore: - - ldw r16, 0(r5) - ldw r17, 4(r5) - ldw r18, 8(r5) - ldw r19, 12(r5) - ldw r20, 16(r5) - ldw r21, 20(r5) - ldw r22, 24(r5) - ldw r23, 28(r5) - ldw gp, 32(r5) - ldw fp, 36(r5) - ldw sp, 40(r5) - - /* Disable interrupts */ - wrctl status, r0 - - ldw ea, 44(r5) - ldw at, 48(r5) - /* FIXME: Always have interrupts enabled when we return from Context_switch */ - ori at, at, 1 - wrctl estatus, at - - eret - - .globl _CPU_Context_restore - -_CPU_Context_restore: - - /* Copy first to second arg, then re-use 2nd half of Context_switch */ - mov r5, r4 - br _CPU_Context_switch_restore - - -/* ===================================================================== */ - - .globl _exception_vector - -_exception_vector: - - /* - * First, re-wind so we're pointed to the instruction where the exception - * occurred. - */ - - addi ea, ea, -4 - - /* - * Now test to determine the cause of the exception. - */ - - /* TODO: Look at [ea] if there was an unknown/trap instruction */ - - /* If interrupts are globally disabled, it certainly was no interrupt */ - rdctl et, estatus - andi et, et, 1 - beq et, zero, _Exception_Handler - - /* If no interrupts are pending, it was a software exception */ - rdctl et, ipending - beq et, zero, _Exception_Handler - - /* - * Falling through to here means that this was a hardware interrupt. - */ - - br _ISR_Handler - -/* ===================================================================== - * Exception handler: - * Responsible for unimplemented instructions and other software - * exceptions. Not responsible for hardware interrupts. Currently, - * software exceptions are regarded as error conditions, and the - * handling isn't perfect. */ - -_Exception_Handler: - - /* stw et, 108(sp') => stw et, -20(sp) */ - stw et, -20(sp) - mov et, sp - addi sp, sp, -128 - - stw r1, 0(sp) - stw r2, 4(sp) - stw r3, 8(sp) - - rdctl r1, estatus - rdctl r2, ienable - rdctl r3, ipending - - stw r4, 12(sp) - stw r5, 16(sp) - stw r6, 20(sp) - stw r7, 24(sp) - stw r8, 28(sp) - stw r9, 32(sp) - stw r10, 36(sp) - stw r11, 40(sp) - stw r12, 44(sp) - stw r13, 48(sp) - stw r14, 52(sp) - stw r15, 56(sp) - stw r16, 60(sp) - stw r17, 64(sp) - stw r18, 68(sp) - stw r19, 72(sp) - stw r20, 76(sp) - stw r21, 80(sp) - stw r22, 84(sp) - stw r23, 88(sp) - stw gp, 92(sp) - stw fp, 96(sp) - /* sp */ - stw et, 100(sp) - stw ra, 104(sp) - /* stw et, 108(sp) */ - stw ea, 112(sp) - - /* status */ - stw r1, 116(sp) - /* ienable */ - stw r2, 120(sp) - /* ipending */ - stw r3, 124(sp) - - /* - * Restore the global pointer. - */ - - movhi gp, %hiadj(_gp) - addi gp, gp, %lo(_gp) - - /* - * Pass a pointer to the stack frame as the input argument of the - * exception handler (CPU_Exception_frame *). - */ - - mov r4, sp - - /* - * Call the exception handler. - */ - - .extern __Exception_Handler - call __Exception_Handler - -stuck_in_exception: - br stuck_in_exception - - /* - * Restore the saved registers, so that all general purpose registers - * have been restored to their state at the time the interrupt occured. - */ - - ldw r1, 0(sp) - ldw r2, 4(sp) - ldw r3, 8(sp) - ldw r4, 12(sp) - ldw r5, 16(sp) - ldw r6, 20(sp) - ldw r7, 24(sp) - ldw r8, 28(sp) - ldw r9, 32(sp) - ldw r10, 36(sp) - ldw r11, 40(sp) - ldw r12, 44(sp) - ldw r13, 48(sp) - ldw r14, 52(sp) - ldw r15, 56(sp) - ldw r16, 60(sp) - ldw r17, 64(sp) - ldw r18, 68(sp) - ldw r19, 72(sp) - ldw r20, 76(sp) - ldw r21, 80(sp) - ldw r22, 84(sp) - ldw r23, 88(sp) - ldw gp, 92(sp) - ldw fp, 96(sp) - ldw ra, 104(sp) - - /* Disable interrupts */ - wrctl status, r0 - - ldw ea, 112(sp) - ldw et, 116(sp) - - /* FIXME: Enable interrupts after exception processing */ - ori et, et, 1 - wrctl estatus, et - ldw et, 108(sp) - - /* Restore stack pointer */ - ldw sp, 100(sp) - - eret - -/* ===================================================================== */ - - .section .text - -_ISR_Handler: - - /* - * Process an external hardware interrupt. - * - * First, preserve all callee saved registers on - * the stack. (See the Nios2 ABI documentation for details). - * - * Do we really need to save all? - * - * If this is interrupting a task (and not another interrupt), - * everything is saved into the task's stack, thus putting us - * in a situation similar to when the task calls a subroutine - * (and only the CPU_Context_Control subset needs to be changed) - */ - - rdctl et, estatus - - /* Keep this in the same order as CPU_Interrupt_frame: */ - - addi sp, sp, -76 - stw r1, 0(sp) - stw r2, 4(sp) - stw r3, 8(sp) - stw r4, 12(sp) - stw r5, 16(sp) - stw r6, 20(sp) - stw r7, 24(sp) - stw r8, 28(sp) - stw r9, 32(sp) - stw r10, 36(sp) - stw r11, 40(sp) - stw r12, 44(sp) - stw r13, 48(sp) - stw r14, 52(sp) - stw r15, 56(sp) - stw ra, 60(sp) - stw gp, 64(sp) - /* et contains status */ - stw et, 68(sp) - stw ea, 72(sp) - - /* - * Obtain a bitlist of the pending interrupts. - */ - - rdctl et, ipending - - /* - * Restore the global pointer to the expected value. - */ - - movhi gp, %hiadj(_gp) - addi gp, gp, %lo(_gp) - - /* - * Search through the bit list stored in r24(et) to find the first enabled - * bit. The offset of this bit is the index of the interrupt that is - * to be handled. - */ - - mov r4, zero -6: - andi r3, r24, 1 - bne r3, zero, 7f - addi r4, r4, 1 - srli r24, r24, 1 - br 6b -7: - - /* - * Having located the interrupt source, r4 contains the index of the - * interrupt to be handled. r5, the 2nd argument to the function, - * will point to the CPU_Interrupt_frame. - */ - - mov r5, sp - - .extern __ISR_Handler - call __ISR_Handler - - /* - * Now that the interrupt processing is complete, prepare to return to - * the interrupted code. - */ - - /* - * Restore the saved registers, so that all general purpose registers - * have been restored to their state at the time the interrupt occured. - */ - - ldw r1, 0(sp) - ldw r2, 4(sp) - ldw r3, 8(sp) - ldw r4, 12(sp) - ldw r5, 16(sp) - ldw r6, 20(sp) - ldw r7, 24(sp) - ldw r8, 28(sp) - ldw r9, 32(sp) - ldw r10, 36(sp) - ldw r11, 40(sp) - ldw r12, 44(sp) - ldw r13, 48(sp) - ldw r14, 52(sp) - ldw r15, 56(sp) - ldw ra, 60(sp) - ldw gp, 64(sp) - - /* Disable interrupts */ - wrctl status, r0 - - /* Restore the exception registers */ - - /* load saved ea into ea */ - ldw ea, 72(sp) - /* load saved estatus into et */ - ldw et, 68(sp) - /* Always have interrupts enabled when we return from interrupt */ - ori et, et, 1 - wrctl estatus, et - /* Restore the stack pointer */ - addi sp, sp, 76 - - /* - * Return to the interrupted instruction. - */ - eret - - |