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##=============================================================================
##
##      vectors.S
##
##      CalmRISC32 exception vectors
##
##=============================================================================
## ####ECOSGPLCOPYRIGHTBEGIN####                                            
## -------------------------------------------                              
## This file is part of eCos, the Embedded Configurable Operating System.   
## Copyright (C) 1998, 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
##
## eCos is free software; you can redistribute it and/or modify it under    
## the terms of the GNU General Public License as published by the Free     
## Software Foundation; either version 2 or (at your option) any later      
## version.                                                                 
##
## eCos is distributed in the hope that it will be useful, but WITHOUT      
## ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or    
## FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License    
## for more details.                                                        
##
## You should have received a copy of the GNU General Public License        
## along with eCos; if not, write to the Free Software Foundation, Inc.,    
## 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.            
##
## As a special exception, if other files instantiate templates or use      
## macros or inline functions from this file, or you compile this file      
## and link it with other works to produce a work based on this file,       
## this file does not by itself cause the resulting work to be covered by   
## the GNU General Public License. However the source code for this file    
## must still be made available in accordance with section (3) of the GNU   
## General Public License v2.                                               
##
## This exception does not invalidate any other reasons why a work based    
## on this file might be covered by the GNU General Public License.         
## -------------------------------------------                              
## ####ECOSGPLCOPYRIGHTEND####                                              
##=============================================================================
#######DESCRIPTIONBEGIN####
##
## Author(s):   msalter
## Contributors: msalter        
## Date:        2001-02-12
## Purpose:     CalmRISC32 exception vectors
## Description: This file defines the code placed into the exception
##              vectors. It also contains the first level default VSRs
##              that save and restore state for both exceptions and
##              interrupts.
##
######DESCRIPTIONEND####
##
##=============================================================================

#include <pkgconf/system.h>     
#include <pkgconf/hal.h>
#include <pkgconf/hal_calm32.h>

#ifdef CYGPKG_KERNEL
# include <pkgconf/kernel.h>    
#else
# undef CYGFUN_HAL_COMMON_KERNEL_SUPPORT
# undef CYGIMP_HAL_COMMON_INTERRUPTS_USE_INTERRUPT_STACK
#endif
                        
#include <cyg/hal/arch.inc>     
#include <cyg/hal/hal_arch.h>   

        .macro  txreg reg
    99:
        cld     r0,fr29
        cmp     eq r0,#0
        brfd    99b
         nop
        cld     fr30,\reg
        ld      r0,#1
        cld     fr29,r0
        .endm

        .extern cyg_instrument

##-----------------------------------------------------------------------------
## Hardware supplied vectors

        .macro  cpu_vector  vsr_nr
        setsr   bs
        clrsr   rs0
        clrsr   rs1
        nop
        push    r8
        brad    __exc_trampoline
         ld     r8,#\vsr_nr
        .endm
        
##==========================================================================
## Hardware exception vectors.
##
        .section ".vectors","ax"
        .global reset_vector
reset_vector:
        ldw     r0,#_start
        jmpd    r0
         nop

        # 0x20 - FIQ  
        .p2align 5
        cpu_vector 0
        
        # 0x40 - IRQ
        .p2align 5
        cpu_vector 1
        
        # 0x50 - COP
        .p2align 4
        cpu_vector 2
        
        # 0x60 - DABRT
        .p2align 4
        cpu_vector 3
        
        # 0x70 - IABRT
        .p2align 4
        cpu_vector 4
        
        # 0x80 - PRIV
        .p2align 4
        cpu_vector 5
        
        # 0xA0 - UNIMPL
        .p2align 5
        cpu_vector 6
        
        # 0xC0 - TRACE
        .p2align 5
        cpu_vector 7
        
        # 0x100 - SWI 0
        .p2align 6
        cpu_vector 8
        
        # SWI 1
        .p2align 4
        cpu_vector 8
        
        # SWI 2
        .p2align 4
        cpu_vector 8
        
        # SWI 3
        .p2align 4
        cpu_vector 8
        
        # SWI 4
        .p2align 4
        cpu_vector 8
        
        # SWI 5
        .p2align 4
        cpu_vector 8
        
        # SWI 6
        .p2align 4
        cpu_vector 8
        
        # SWI 7
        .p2align 4
        cpu_vector 8
        
        # SWI 8
        .p2align 4
        cpu_vector 8
        
        # SWI 9
        .p2align 4
        cpu_vector 8
        
        # SWI 10
        .p2align 4
        cpu_vector 8
        
        # SWI 11
        .p2align 4
        cpu_vector 8
        
        # SWI 12
        .p2align 4
        cpu_vector 8
        
        # SWI 13
        .p2align 4
        cpu_vector 8
        
        # SWI 14
        .p2align 4
        cpu_vector 8
        
        # SWI 15
        .p2align 4
        cpu_vector 8

__exc_trampoline:
        push    r8      // vsr number
        sl2     r8      // offset into vsr table
        ldw     r8,@[r8 + 0]
        jmpd    r8
         pop    r8
        
##-----------------------------------------------------------------------------
## Startup code

        .text
        
FUNC_START _start
        # default vector table
        ld      r0,#0
        ld      vbr,r0

        # ensure privileged mode with all bank1 register view
        setsr   pm
        setsr   bs
        clrsr   rs0
        clrsr   rs1
        
        # Initialize hardware
        hal_cpu_init
        hal_diag_init
        hal_memc_init
        hal_cache_init
        hal_timer_init
                
        # load initial stack pointer
        ldw     sp,#__startup_stack

        clrsr   bs
        nop
        ldw     sp,#__user_stack
        setsr   bs
        nop

        hal_mon_init
                
#ifdef CYG_HAL_STARTUP_ROM
        # Copy data from ROM to RAM

        .extern hal_copy_data
        ldw     r0,#hal_copy_data
        jsrd    r0
         nop
#endif

        # Zero BSS

        .extern hal_zero_bss
        ldw     r0,#hal_zero_bss
        jsrd    r0
         nop

        # Call variant and platform HAL
        # initialization routines.

        .extern hal_variant_init
        ldw     r0,#hal_variant_init
        jsrd    r0
         nop

        .extern hal_platform_init
        ldw     r0,#hal_platform_init
        jsrd    r0
         nop

        # Call constructors
        .extern cyg_hal_invoke_constructors
        ldw     r0,#cyg_hal_invoke_constructors
        jsrd     r0
         nop

#if defined(CYGDBG_HAL_DEBUG_GDB_INCLUDE_STUBS)
        .extern initialize_stub
        ldw     r0,#initialize_stub
        jsrd     r0
         nop
#endif
        
#if defined(CYGDBG_HAL_CALM32_DEBUG_GDB_CTRLC_SUPPORT)
        .extern hal_ctrlc_isr_init
        ldw     r0,#hal_ctrlc_isr_init
        jsrd     r0
         nop
#endif

        # Call cyg_start        
        
        .extern cyg_start
#if 0
        clrsr   pm
        nop
        clrsr   bs
        nop
#endif
        ld      fp,sp

        ldw     lr,#_start
        ldw     r0,#cyg_start
        jmpd    r0
         nop
FUNC_END _start


        .macro switch_stack_and_save_regs tmpvar
        // save vector number temporarily
        push    r9
        ldw     r9,#\tmpvar
        ldw     @[r9 + 0],r8
        pop     r9

        // Make sure we use the gdb stack
        ldw     r8,#__GDB_stack
        cmpu    gt sp,r8
        brtd    0f
         nop
        ldw     r8,#__GDB_stack_base
        cmpu    gt sp,r8
        brtd    1f
         nop
    0:
        // need to switch stack
        ld      r8,sp
        add     r8,#4
        ldw     sp,#__GDB_stack
        push    r8
        push    r14
        push    r13
        push    r12
        sub     r8,#4
        brad    2f
         ldw    r8,@[r8+0]
    1:
        // already using gdb stack
        pop     r8
        // save bank 1 regs
        push    q3
    2:
        // save rest of bank1 regs
        push    q2
        push    q1
        push    q0
        
        // save bank 0 regs
        setsr   rs1
        nop
        push    q1
        push    q0
        clrsr   rs1
        setsr   rs0
        nop
        push    q1
        push    q0
        clrsr   rs0
        nop
        // save special regs
        ld      r0,ssr_expt
        push    r0
        ld      r0,ssr_swi
        push    r0
        ld      r0,ssr_fiq
        push    r0
        ld      r0,ssr_irq
        push    r0
        ld      r0,spc_expt
        push    r0
        ld      r0,spc_swi
        push    r0
        ld      r0,spc_fiq
        push    r0
        ld      r0,spc_irq
        push    r0
        ld      r0,vbr
        push    r0

        ldw     r8,#\tmpvar
        ldw     r8,@[r8+0]
        push    r8
        .endm

        .macro restore_regs
        // discard vector
        pop     r0
        // restore special regs
        pop     r0
        ld      vbr,r0
        pop     r0
        ld      spc_irq,r0
        pop     r0
        ld      spc_fiq,r0
        pop     r0
        ld      spc_swi,r0
        pop     r0
        ld      spc_expt,r0
        pop     r0
        ld      ssr_irq,r0
        pop     r0
        ld      ssr_fiq,r0
        pop     r0
        ld      ssr_swi,r0
        pop     r0
        ld      ssr_expt,r0
        // restore bank 0 regs
        setsr   rs1
        nop
        pop     q0
        pop     q1
        clrsr   rs1
        setsr   rs0
        nop
        pop     q0
        pop     q1
        clrsr   rs0
        nop
        // restore bank 1 regs
        pop     q0
        pop     q1
        pop     q2
        pop     q3
        .endm


##-----------------------------------------------------------------------------
## Default exception VSR.
## Saves machine state and calls external handling code.
## On entry, the original R8 has been pushed on the stack and R8 now
## contains the vector number.
        
FUNC_START __default_exception_vsr

        switch_stack_and_save_regs __expt_temp

        // call exception handler
        ldw     r8,#cyg_hal_exception_handler
        jsrd    r8
         ld     r0,sp

        restore_regs
        
        ret_expt
         nop

FUNC_END   __default_exception_vsr

##-----------------------------------------------------------------------------
## Default swi VSR.
## Saves machine state and calls external handling code.
## On entry, the original R8 has been pushed on the stack and R8 now
## contains the vector number.
        
FUNC_START __default_swi_vsr

        switch_stack_and_save_regs __swi_temp

        // call exception handler
        ldw     r8,#cyg_hal_exception_handler
        jsrd    r8
         ld     r0,sp

        restore_regs

        ret_swi
         nop

FUNC_END  __default_swi_vsr

##------------------------------------------------------------------------------
## Default interrupt VSR.
## Saves machine state and calls appropriate ISR. When done, calls
## interrupt_end() to finish up and possibly reschedule.        

FUNC_START __default_fiq_vsr
        switch_stack_and_save_regs __fiq_temp

        ldw     r8,#hal_interrupt_data
        ldw     r1,@[r8 + 0]
        ldw     r8,#hal_interrupt_handlers
        ldw     r8,@[r8 + 0]

        // call fiq handler
        jsrd    r8
         ld     r0,#0

        restore_regs

        ret_fiq
         nop
FUNC_END   __default_fiq_vsr
        
FUNC_START __default_irq_vsr
        switch_stack_and_save_regs __irq_temp

        ldw     r8,#hal_interrupt_data
        ldw     r1,@[r8 + 4]
        ldw     r8,#hal_interrupt_handlers
        ldw     r8,@[r8 + 4]

        // call fiq handler
        jsrd    r8
         ld     r0,#1
        
        restore_regs

        ret_irq
         nop
FUNC_END   __default_irq_vsr

##-----------------------------------------------------------------------------
## Execute pending DSRs on the interrupt stack with interrupts enabled.
## Note: this can only be called from code running on a thread stack
        
#ifdef CYGIMP_HAL_COMMON_INTERRUPTS_USE_INTERRUPT_STACK
        .extern cyg_interrupt_call_pending_DSRs

FUNC_START hal_interrupt_stack_call_pending_DSRs
FUNC_END hal_interrupt_stack_call_pending_DSRs
#endif          

##-----------------------------------------------------------------------------
## Short circuit in case any code tries to use "__gccmain()"

FUNC_START __gccmain
        jmpd    lr
         nop
FUNC_END __gccmain

##-----------------------------------------------------------------------------
## Interrupt Stack.
## Used during intialization and for executing ISRs.
        
        .section ".bss"

        .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:

        .long   0
        
#ifdef CYGDBG_HAL_DEBUG_GDB_INCLUDE_STUBS
        .balign 16
__GDB_stack_base:
        .rept 0x400
        .byte 0
        .endr
__GDB_stack:
        .long   0
#endif
        .balign 16
__startup_stack_base:
#ifdef CYGIMP_HAL_COMMON_INTERRUPTS_USE_INTERRUPT_STACK
        .rept 512
#else
        .rept CYGNUM_HAL_COMMON_INTERRUPTS_STACK_SIZE
#endif
        .byte 0
        .endr
        .balign 16
__startup_stack:
        .long   0

        .balign 16
__user_stack_base:
#ifdef CYGIMP_HAL_COMMON_INTERRUPTS_USE_INTERRUPT_STACK
        .rept 512
#else
        .rept CYGNUM_HAL_COMMON_INTERRUPTS_STACK_SIZE
#endif
        .byte 0
        .endr
        .balign 16
__user_stack:
        .long   0

__expt_temp:
        .long   0
__swi_temp:
        .long   0
__irq_temp:
        .long   0
__fiq_temp:
        .long   0


##-----------------------------------------------------------------------------
## VSR table.
## The main interrupt code indirects through here to find the VSR
## to execute for each architecture defined interrupt.
## This is only used for simulated targets, on real targets a fixed location VSR
## table is now allocated at 0x80000100.

#ifndef CYG_HAL_CALM32_VSR_TABLE_DEFINED
        
##      .section ".vsr_table","a"
        
        .data
                        
        .globl  hal_vsr_table
hal_vsr_table:
        .long   __default_fiq_vsr       // FIQ
        .long   __default_irq_vsr       // IRQ
        .long   __default_exception_vsr // COP
        .long   __default_exception_vsr // DABRT
        .long   __default_exception_vsr // IABRT
        .long   __default_exception_vsr // PRIV
        .long   __default_exception_vsr // UNIMPL
        .long   __default_exception_vsr // TRACE
        .long   __default_swi_vsr       // SWI
#endif  
        
        .balign 16
#ifdef CYGSEM_HAL_VIRTUAL_VECTOR_SUPPORT
        ## Vectors used to communicate between eCos and ROM environments
        .globl  hal_virtual_vector_table
hal_virtual_vector_table:
        .rept   64
        .long   0
        .endr
#endif
        
#------------------------------------------------------------------------------
# Interrupt vector tables.
# These tables contain the isr, data and object pointers used to deliver
# interrupts to user code.
# hal_interrupt_level contains the interrupt level set by 
# HAL_INTERRUPT_CONFIGURE().
# This is a default set that provide support only for the single external
# interrupt. Platforms or boards are expected to define their own versions
# of these if they have their own interrupt mappings.

#ifndef CYG_HAL_CALM32_ISR_TABLES_DEFINED

        .extern hal_default_isr
        
        .data

        .globl  hal_interrupt_handlers
hal_interrupt_handlers:
        .long   hal_default_isr
        .long   hal_default_isr


        .globl  hal_interrupt_data
hal_interrupt_data:
        .long   0
        .long   0

        .globl  hal_interrupt_objects
hal_interrupt_objects:
        .long   0
        .long   0
#endif

        .data
        .globl __break_inst_in_data
__break_inst_in_data:
        .short 0x80e0


##-----------------------------------------------------------------------------
## end of vectors.S