vectors.s

eCos操作系统源码

return_from_exception_or_interrupt: 
        // save sp, but remove space for the parameter flush back area
        // (as per calling conventions) at the same time
        addi    16,sp,ep
                
        sld.w   CYGARC_REG_PSW[ep],r7
        sld.w   CYGARC_REG_R1[ep],r1
        sld.w   CYGARC_REG_PC[ep],r6
        sld.w   CYGARC_REG_R2[ep],r2       
        // disable interrupts while restoring context
        ld.w    CYGARC_REG_VECTOR[ep],r4
        stsr    PSW,r8
        cmp     CYGNUM_HAL_VECTOR_TRAP00,r4
        bge     10f
        ori     CYGARC_PSW_NP,r8,r8     // returning from NMI
        ori     CYGARC_PSW_ID,r8,r8     // disable interrupt
        ldsr    r8,PSW
        ldsr    r7,FEPSW
        ldsr    r6,FEPC
        br      30f
10:     cmp     CYGNUM_HAL_ISR_MIN,r4   // exception or interrupt
        bge     20f
        ori     CYGARC_PSW_EP,r8,r8     // returning from exception
20:     ori     CYGARC_PSW_ID,r8,r8     // disable interrupt
        ldsr    r8,PSW
        ldsr    r7,EIPSW                // Avoid pipeline bubbles
        ldsr    r6,EIPC
30:     sld.w   CYGARC_REG_R4[ep],r4
        sld.w   CYGARC_REG_R5[ep],r5      
        sld.w   CYGARC_REG_R6[ep],r6      
        sld.w   CYGARC_REG_R7[ep],r7      
        sld.w   CYGARC_REG_R8[ep],r8      
        sld.w   CYGARC_REG_R9[ep],r9      
        sld.w   CYGARC_REG_R10[ep],r10       
        sld.w   CYGARC_REG_R11[ep],r11     
        sld.w   CYGARC_REG_R12[ep],r12
        sld.w   CYGARC_REG_R13[ep],r13              
        sld.w   CYGARC_REG_R14[ep],r14       
        sld.w   CYGARC_REG_R15[ep],r15       
        sld.w   CYGARC_REG_R16[ep],r16       
        sld.w   CYGARC_REG_R17[ep],r17       
        sld.w   CYGARC_REG_R18[ep],r18               
        sld.w   CYGARC_REG_R19[ep],r19       
#ifndef CYGDBG_HAL_COMMON_INTERRUPTS_SAVE_MINIMUM_CONTEXT
        sld.w   CYGARC_REG_R20[ep],r20       
        sld.w   CYGARC_REG_R21[ep],r21       
        sld.w   CYGARC_REG_R22[ep],r22       
        sld.w   CYGARC_REG_R23[ep],r23       
        sld.w   CYGARC_REG_R24[ep],r24       
        sld.w   CYGARC_REG_R25[ep],r25       
        sld.w   CYGARC_REG_R26[ep],r26       
        sld.w   CYGARC_REG_R27[ep],r27       
        sld.w   CYGARC_REG_R28[ep],r28       
#endif
        sld.w   CYGARC_REG_R29[ep],r29 // NB frame pointer
        sld.w   CYGARC_REG_LP[ep],lp
        sld.w   CYGARC_REG_SP[ep],sp
        sld.w   CYGARC_REG_EP[ep],ep
        reti
        
        // Handle interrupt - these are typically vectored into user code
do_interrupt:
        mov     sp,ep                   // save pointer to regs frame
        // leave space for the parameter flush back area (as per calling
        // conventions)
        addi    -16,sp,sp

#ifdef CYGIMP_HAL_COMMON_INTERRUPTS_USE_INTERRUPT_STACK
	// Switch to interrupt stack
        lea     irq_level,r6            // current number of nested interrupts
        ld.w    0[r6],r7
        addi    1,r7,r8
        st.w    r8,0[r6]
        cmp     0,r7                    // if was zero, switch stacks
        bne     10f
        mov     sp,r1                   // save old stack pointer
        lea     __interrupt_stack-20,r2
        mov     r2,sp
        st.w    r1,16[sp]                
10:
#endif // CYGIMP_HAL_COMMON_INTERRUPTS_USE_INTERRUPT_STACK

        // The entire CPU state is now stashed on the stack,
        // increment the scheduler lock and handle the interrupt

#ifdef CYGFUN_HAL_COMMON_KERNEL_SUPPORT			
        .extern	_cyg_scheduler_sched_lock
        lea     _cyg_scheduler_sched_lock,r7
        ld.w    0[r7],r8
        addi    1,r8,r8
        st.w    r8,0[r7]
#endif

#if defined(CYGPKG_KERNEL_INSTRUMENT) && \
    defined(CYGDBG_KERNEL_INSTRUMENT_INTR)
        lea     RAISE_INTR,r6                   // arg0 = type = INTR,RAISE
        ld.w    CYGARC_REG_VECTOR[ep],r7        // args = vector
        mov     r0,r8                           // arg2 = 0
        jarl    _cyg_instrument,r31
#endif

#if defined(CYGDBG_HAL_DEBUG_GDB_CTRLC_SUPPORT) \
    || defined(CYGDBG_HAL_DEBUG_GDB_BREAK_SUPPORT)
	// If we are supporting Ctrl-C interrupts from GDB, we must squirrel
	// away a pointer to the save interrupt state here so that we can
	// plant a breakpoint at some later time.
	
	.extern	_hal_saved_interrupt_state
	lea     _hal_saved_interrupt_state,r8
        st.w    ep,0[r8]
#endif

#ifdef CYGIMP_KERNEL_INTERRUPTS_CHAIN
        mov     r0,r8                           // vector # (overloaded by kernel)
#else	
        ld.w    CYGARC_REG_VECTOR[ep],r6        // vector #
        addi    -CYGNUM_HAL_ISR_MIN,r6,r8
        shl     2,r8
#endif        
        lea     _hal_interrupt_objects,r1
        add     r8,r1
        ld.w    0[r1],r29                       // save object handle
        lea     _hal_interrupt_data,r1
        add     r8,r1
        ld.w    0[r1],r7                        // handler data
        lea     _hal_interrupt_handlers,r1
        add     r8,r1
        mov     ep,r8                           // pointer to saved registers
        ld.w    0[r1],r1                        // handler routine
#ifdef CYGIMP_KERNEL_INTERRUPTS_CHAIN
        ld.w    CYGARC_REG_VECTOR[ep],r6        // vector #
#endif        
        jarl    call_via_r1,r31
        
#ifdef CYGIMP_HAL_COMMON_INTERRUPTS_USE_INTERRUPT_STACK
	// If we are returning from the last nested interrupt, move back
	// to the thread stack. interrupt_end() must be called on the
	// thread stack since it potentially causes a context switch.
        lea     irq_level,r6
        ld.w    0[r6],r7
        addi    -1,r7,r8
        st.w    r8,0[r6]
        cmp     0,r8
        bne     10f
        ld.w    16[sp],sp       // Restore non-interrupt stack at last interrupt
                                // this is offset 16 because of parameter
                                // flush back area
10:
#endif // CYGIMP_HAL_COMMON_INTERRUPTS_USE_INTERRUPT_STACK

#ifdef CYGFUN_HAL_COMMON_KERNEL_SUPPORT
	// The return value from the handler (in r10) will indicate whether a 
	// DSR is to be posted. Pass this together with a pointer to the
	// interrupt object we have just used to the interrupt tidy up routine.

        mov     r10,r6                          // interrupt handler return code
        mov     r29,r7                          // object handle
        mov     ep,r8                           // register frame
        jarl    _interrupt_end,r31              // post any bottom layer handle
        
#endif
        br      return_from_exception_or_interrupt

#ifdef CYGIMP_HAL_COMMON_INTERRUPTS_USE_INTERRUPT_STACK
        .globl  _hal_interrupt_stack_call_pending_DSRs
_hal_interrupt_stack_call_pending_DSRs:
        stsr    PSW,r9
        di                              // disable interrupts while changing stack
	// Switch to interrupt stack
        lea     irq_level,r6            // current number of nested interrupts
        mov     1,r7                    // note: this can never be non-zero at this point
        st.w    r7,0[r6]
        mov     sp,r1                   // save old stack pointer
        lea     __interrupt_stack-32,r8 // 32 for 16-byte parameter flush back
                                        // plus 12 bytes for following reg saves
                                        // plus 4 bytes to preserve alignment
        mov     r8,sp        
        st.w    r1,16[sp]               
        st.w    r9,20[sp]
        st.w    lp,24[sp]
        ei
       	jarl    _cyg_interrupt_call_pending_DSRs,lp
        di
        ld.w    24[sp],lp                // restore state
        ld.w    20[sp],r6
        ld.w    16[sp],sp
        lea     irq_level,r7
        st.w    r0,0[r7]
        ldsr    r6,PSW
        jmp     [lp]
#endif // CYGIMP_HAL_COMMON_INTERRUPTS_USE_INTERRUPT_STACK
                
//
// Indirect subroutine call, via R1

call_via_r1:    
        jmp     [r1]
                                        
//
// Reset the board
//
        .globl  _hal_reset_board
_hal_reset_board:   
        di                      // Turn off interrupts
        // Don't process NMIs
        lea     __allow_nmi,r1
        st.w    r0,0[r1]
        jmp     [r0]            // Restart machine        

#if !defined(CYGSEM_HAL_NEC_INLINE_INTERRUPT_FUNCTIONS)
        .globl  _hal_disable_interrupts
_hal_disable_interrupts:
        stsr    PSW,r10
        di
        jmp     [lp]

        .globl  _hal_enable_interrupts
_hal_enable_interrupts:
        stsr    PSW,r6
        ei
        jmp     [lp]

        .globl  _hal_restore_interrupts
_hal_restore_interrupts:
        ldsr    r6,PSW
        jmp     [lp]
#endif        
                
// -------------------------------------------------------------------------
        .section ".ram_vectors","awx",@progbits

#if defined(CYG_HAL_STARTUP_ROM)
// Trap jump table - used by builtin ROM
__vsr_table:            
        .rept   CYGNUM_HAL_VSR_COUNT
        .word   0x00000794,0,0,0   // jr 0x0100xx0, nop, nop, nop
        .endr
__vsr_table_end:
#endif

#if defined(CYG_HAL_STARTUP_ROM) || defined(CYG_HAL_STARTUP_ROMRAM)        
_hal_vsr_table:
        .rept   CYGNUM_HAL_EXCEPTION_COUNT
        .word   do_exception
        .endr
        .rept   CYGNUM_HAL_ISR_COUNT
        .word   do_interrupt
        .endr

// Flag to indicate whether NMIs are allowed
// Without this, if we do a soft reset (using hal_plf_reset_board above)
// we may process NMIs like the watchdog timeout before the system can
// accept them
__allow_nmi:
        .word 0
        
        .balign 64
_hal_virtual_vector_table:      
        .rept   CYGNUM_CALL_IF_TABLE_SIZE
        .word   0
        .endr

#if CYGINT_HAL_V85X_ICE_DEBUG
        .globl  _hal_v85x_ice_syscall_info
_hal_v85x_ice_syscall_info:
         .rept  48
         .long  0
         .endr
#endif // if CYGINT_HAL_V85X_ICE_DEBUG
#endif // if defined(CYG_HAL_STARTUP_ROM) || defined(CYG_HAL_STARTUP_ROMRAM)
        
        .data
// Initial stack        
        .rept   1024
        .byte   0
        .endr
__startup_stack:        

#ifndef CYGNUM_HAL_COMMON_INTERRUPTS_STACK_SIZE
#define CYGNUM_HAL_COMMON_INTERRUPTS_STACK_SIZE 4096
#endif
#ifdef CYGIMP_HAL_COMMON_INTERRUPTS_USE_INTERRUPT_STACK
	.balign 16
	.global _cyg_interrupt_stack_base
_cyg_interrupt_stack_base:
__interrupt_stack_base:
        .rept CYGNUM_HAL_COMMON_INTERRUPTS_STACK_SIZE
        .byte 0
        .endr
	.balign 16
	.global _cyg_interrupt_stack
_cyg_interrupt_stack:
__interrupt_stack:
irq_level:
	.long	0
#endif

        
// Interrupt vector tables.
// These tables contain the isr, data and object pointers used to deliver
// interrupts to user code.

	.extern _hal_default_isr

	.globl	_hal_interrupt_handlers
_hal_interrupt_handlers:
	.rept	CYGNUM_HAL_ISR_COUNT
	.long	_hal_default_isr
	.endr

	.globl	_hal_interrupt_data
_hal_interrupt_data:
	.rept	CYGNUM_HAL_ISR_COUNT
	.long	0
	.endr

	.globl	_hal_interrupt_objects
_hal_interrupt_objects:
	.rept	CYGNUM_HAL_ISR_COUNT
	.long	0
	.endr

// -------------------------------------------------------------------------
// EOF vectors.S