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/*=============================================================================

//

//      vectors.S

//

//      SPARClite vectors and bootup code

//

//=============================================================================

//####ECOSGPLCOPYRIGHTBEGIN####

// -------------------------------------------

// This file is part of eCos, the Embedded Configurable Operating System.

// Copyright (C) 1998, 1999, 2000, 2001, 2002 Red Hat, 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.,

// 59 Temple Place, Suite 330, Boston, MA 02111-1307 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.

//

// This exception does not invalidate any other reasons why a work based on

// this file might be covered by the GNU General Public License.

//

// Alternative licenses for eCos may be arranged by contacting Red Hat, Inc.

// at http://sources.redhat.com/ecos/ecos-license/

// -------------------------------------------

//####ECOSGPLCOPYRIGHTEND####

//=============================================================================

//#####DESCRIPTIONBEGIN####

//

// Author(s):   hmt

// Contributors:hmt

// Date:        1998-12-15

// Purpose:     SPARClite vector code

// Description: This file contains the code which hangs off SPARClite vectors

//              including reset; it handles register under/overflow as well

//              as bootup, anything else is deferred to the default interrupt

//              or exception vsrs respectively.  See vec_[ix]vsr.S ...

//

//####DESCRIPTIONEND####

//

//===========================================================================*/

!-----------------------------------------------------------------------------

//      .file   "vectors.S"

!-----------------------------------------------------------------------------

#include 

#include 

#include 

#include CYGBLD_HAL_PLATFORM_H          // Platform config file

#ifdef CYGPKG_KERNEL

# include 

#else

# undef CYGIMP_HAL_COMMON_INTERRUPTS_USE_INTERRUPT_STACK

# undef CYGFUN_HAL_COMMON_KERNEL_SUPPORT

#endif

#if defined( CYGPKG_HAL_SPARCLITE_SIM ) || \

    defined( CYGIMP_HAL_COMMON_INTERRUPTS_USE_INTERRUPT_STACK )

#define BOOTUPSTACK_IS_INTERRUPTSTACK

#endif

//#define CYGHWR_HAL_SPARCLITE_MULTIPLE_VECTOR_TRAPPING

#ifndef CYGHWR_HAL_SPARCLITE_HAS_ASR17

#ifndef CYGHWR_HAL_SPARCLITE_MULTIPLE_VECTOR_TRAPPING

#error Single Vector Trapping (SVT) demands ASR17

#endif

#endif

#ifdef CYG_HAL_STARTUP_ROM

# ifndef CYGHWR_HAL_SPARCLITE_MULTIPLE_VECTOR_TRAPPING

! ROM startup and Single Vector Trapping demands a copy to RAM.

! Otherwise it may be configured in, but it is not required.

#  ifndef CYGIMP_HAL_SPARCLITE_COPY_VECTORS_TO_RAM

#   define CYGIMP_HAL_SPARCLITE_COPY_VECTORS_TO_RAM

#  endif

# endif

#endif

!------------------------------------------------------------------------

#include 

#define DELAYS_AFTER_WRPSR_SAME_WINDOW

#define DELAYS_AFTER_WRWIM

!------------------------------------------------------------------------

#ifdef CYGHWR_HAL_SPARCLITE_MULTIPLE_VECTOR_TRAPPING

        .macro  VECTOR_EXCEPTION

        .p2align 4

        rd      %tbr, %l3

        rd      %psr, %l0

        ba      __entry_exception

         and    %l3, TT_MASK, %l4

        .endm

        .macro  VECTOR_INTERRUPT level

        .p2align 4

        rd      %psr, %l0

        mov     \level << 2, %l5

        ba      __entry_interrupt

         mov    \level << 4, %l4

        .endm

        .macro  VECTOR_CODE_WIM name

        .p2align 4

        ba      __entry_\name

         rd     %wim, %l0

        .endm

#endif // CYGHWR_HAL_SPARCLITE_MULTIPLE_VECTOR_TRAPPING

!------------------------------------------------------------------------

! The start of the code; this is the entry point:

        .section ".vectors","ax"

        .global rom_vectors

rom_vectors:

        .global reset_vector

reset_vector:

        ! this code goes to the real reset handler, it will be

        ! overwritten by the start of vectoring handler...

        b       genuine_reset

        nop

        ! usually drop through to:

#ifdef CYGHWR_HAL_SPARCLITE_MULTIPLE_VECTOR_TRAPPING

        ba      __entry_exception       ! reset becomes an exception

         and    %l3, TT_MASK, %l4       ! once we are running

        VECTOR_EXCEPTION                !   1

        VECTOR_EXCEPTION                !   2

        VECTOR_EXCEPTION                !   3

        VECTOR_EXCEPTION                !   4

        VECTOR_CODE_WIM wover           !   5 window overflow

        VECTOR_CODE_WIM wunder          !   6 window underflow

        VECTOR_EXCEPTION                !   7

        VECTOR_EXCEPTION                !   8

        VECTOR_EXCEPTION                !   9

        VECTOR_EXCEPTION                !  10

        VECTOR_EXCEPTION                !  11

        VECTOR_EXCEPTION                !  12

        VECTOR_EXCEPTION                !  13

        VECTOR_EXCEPTION                !  14

        VECTOR_EXCEPTION                !  15

        VECTOR_EXCEPTION                !  16

        VECTOR_INTERRUPT  1             !  17 interrupt_level_1

        VECTOR_INTERRUPT  2             !  18 interrupt_level_2

        VECTOR_INTERRUPT  3             !  19 interrupt_level_3

        VECTOR_INTERRUPT  4             !  20 interrupt_level_4

        VECTOR_INTERRUPT  5             !  21 interrupt_level_5

        VECTOR_INTERRUPT  6             !  22 interrupt_level_6

        VECTOR_INTERRUPT  7             !  23 interrupt_level_7

        VECTOR_INTERRUPT  8             !  24 interrupt_level_8

        VECTOR_INTERRUPT  9             !  25 interrupt_level_9

        VECTOR_INTERRUPT 10             !  26 interrupt_level_10

        VECTOR_INTERRUPT 11             !  27 interrupt_level_11

        VECTOR_INTERRUPT 12             !  28 interrupt_level_12

        VECTOR_INTERRUPT 13             !  29 interrupt_level_13

        VECTOR_INTERRUPT 14             !  30 interrupt_level_14

        VECTOR_INTERRUPT 15             !  31 interrupt_level_15

        VECTOR_EXCEPTION                !  32

        VECTOR_EXCEPTION                !  33

        VECTOR_EXCEPTION                !  34

        VECTOR_EXCEPTION                !  35

        VECTOR_EXCEPTION                !  36

        VECTOR_EXCEPTION                !  37

        VECTOR_EXCEPTION                !  38

        VECTOR_EXCEPTION                !  39

        .rept 216                       ! 40-255 is 216 of them

        VECTOR_EXCEPTION                ! whichever

        .endr

#endif // CYGHWR_HAL_SPARCLITE_MULTIPLE_VECTOR_TRAPPING

#ifndef CYGHWR_HAL_SPARCLITE_MULTIPLE_VECTOR_TRAPPING

real_vector:

        ! here,locals have been set up as follows:

        ! %l0 = psr

        ! %l1 = pc

        ! %l2 = npc

        ! %l3 = tbr

        and     %l3, TT_IS_INTR_MASK, %l4

        cmp     %l4, TT_IS_INTR_VALUE

        bne     not_an_interrupt        ! delay slot does not matter

        ! here be the pre-vector interrupt handler

interrupt:

        and     %l3, 0x0f0, %l4         ! get an interrupt number out

        srl     %l4, 2, %l5             ! to a word address offset

#endif // !CYGHWR_HAL_SPARCLITE_MULTIPLE_VECTOR_TRAPPING

__entry_interrupt:

        sethi   %hi(hal_vsr_table), %l6

        or      %l6, %lo(hal_vsr_table), %l6

        ld      [ %l6 + %l5 ], %l6      ! get vector in %l6

        jmp     %l6                     ! and go there

        srl     %l4, 4, %l3             ! vector number into %l3: so that

                                        ! interrupts and exceptions/traps

                                        ! have the same API to VSRs

#ifndef CYGHWR_HAL_SPARCLITE_MULTIPLE_VECTOR_TRAPPING

not_an_interrupt:

        and     %l3, TT_MASK, %l4

        cmp     %l4, (TRAP_WUNDER << TT_SHL)

        bne,a   not_window_underflow

        cmp     %l4, (TRAP_WOVER << TT_SHL)     ! (if taken)

        ! here be the window underflow handler:

window_underflow:

        ! CWP is trap handler

        ! CWP + 1 is trapped RESTORE instruction

        ! CWP + 2 is invalid context which must be restored

        ! CWP + 3 is next invalid context

        wr      %l0, %psr               ! restore the condition flags

                                        ! (CWP is unchanged)

        ! the following instructions delay enough; no need for NOPs

        rd      %wim, %l0               ! get the wim

#endif // !CYGHWR_HAL_SPARCLITE_MULTIPLE_VECTOR_TRAPPING

__entry_wunder:

        sll     %l0, 1, %l3             ! Rotate wim left

        srl     %l0, __WINSIZE-1, %l0

        wr      %l0, %l3, %wim          ! Install the new wim

#ifdef DELAYS_AFTER_WRWIM

        nop                             ! are these delays needed?

        nop                             ! (following restore uses wim)

        nop

#endif

        restore                         ! Users window

        restore                         ! Her callers window (now valid)

        ldd     [%sp + 0 * 4], %l0      ! restore L & I registers

        ldd     [%sp + 2 * 4], %l2

        ldd     [%sp + 4 * 4], %l4

        ldd     [%sp + 6 * 4], %l6

        ldd     [%sp + 8 * 4], %i0

        ldd     [%sp + 10 * 4], %i2

        ldd     [%sp + 12 * 4], %i4

        ldd     [%sp + 14 * 4], %i6

        save                            ! Back to trap window

        save

        jmp     %l1

        rett    %l2

#ifndef CYGHWR_HAL_SPARCLITE_MULTIPLE_VECTOR_TRAPPING

not_window_underflow:

        bne,a   not_window_overflow

        srl     %l4, 4, %l4             ! (if taken)

        ! here be the window overflow handler:

window_overflow:

        ! CWP + 1 is caller whose SAVE bounced

        ! CWP is trap handler = invalid window

        ! CWP - 1 is next invalid window which needs to be saved

        wr      %l0, %psr               ! restore the condition flags

                                        ! (CWP is unchanged)

        ! the following instructions delay enough; no need for NOPs

        rd      %wim, %l0

#endif // !CYGHWR_HAL_SPARCLITE_MULTIPLE_VECTOR_TRAPPING

__entry_wover:

        mov     %g1, %l3                ! Save g1, we use it to hold the wim

        srl     %l0, 1, %g1             ! Rotate wim right

        sll     %l0, __WINSIZE-1, %l0

        or      %l0, %g1, %g1

        save                            ! Slip into next window

        mov     %g1, %wim               ! Install the new wim

                                        ! (invalidates current window!)

        std     %l0, [%sp + 0 * 4]      ! save L & I registers

        std     %l2, [%sp + 2 * 4]

        std     %l4, [%sp + 4 * 4]

        std     %l6, [%sp + 6 * 4]

        std     %i0, [%sp + 8 * 4]

        std     %i2, [%sp + 10 * 4]

        std     %i4, [%sp + 12 * 4]

        std     %i6, [%sp + 14 * 4]

        restore                         ! Go back to trap window.

        mov     %l3, %g1                ! Restore %g1

        jmpl    %l1,  %g0

        rett    %l2

#ifdef CYGHWR_HAL_SPARCLITE_MULTIPLE_VECTOR_TRAPPING

        // ADDITIONAL code to provide an entry point:

__entry_exception:

        srl     %l4, 4, %l4

#endif // CYGHWR_HAL_SPARCLITE_MULTIPLE_VECTOR_TRAPPING

not_window_overflow:

        ! from here on in, %l4 is the trap number in clear

        cmp     %l4, 128

        bge     1f

        mov     0, %l5                  ! offset 0 for user traps

        cmp     %l4, 36                 ! coprocessor special case

        beq     1f

        mov     4, %l5                  ! ...treated as FP, code 4

        cmp     %l4, 10

        bge     1f

        mov     10, %l5                 ! offset 10 for "others"

        ! if we are here, the trap number is 1-9 inclusive

        ! so put it in %l5 and drop through...

        mov     %l4, %l5

1:

        or      %l5, 16, %l5            ! offset into table is 16... for traps.

        sll     %l5,  2, %l5            ! to a word address offset

        sethi   %hi(hal_vsr_table), %l6

        or      %l6, %lo(hal_vsr_table), %l6

        ld      [ %l6 + %l5 ], %l6      ! get vector in %l6

        jmp     %l6                     ! and go there

        srl     %l5, 2, %l3             ! vector number into %l3: so that

                                        ! interrupts and exceptions/traps

                                        ! have the same API to VSRs

        ! NB that~s eCos vector number not TRAP number above.

        ! and that is the end of the pre-vector trap handler

        .global rom_vectors_end

rom_vectors_end:

        ! these instructions are copied into the reset vector

        ! after startup to _not_ branch to the genuine_reset code below

real_vector_instructions:

        rd      %tbr, %l3

        rd      %psr, %l0

        ! genuine reset code called from time zero:

genuine_reset:                          ! set psr, mask interrupts & traps

        wr      %g0, 0xfc0 + __WIN_INIT, %psr

        nop                             ! mode = prevMode = S, CWP=7

        nop

        nop

        wr      %g0, 0, %wim            ! No invalid windows (yet)

        nop

        nop

        nop

        sethi   %hi(reset_vector), %g1

        andn    %g1, 0xfff, %g1         ! should not be needed

        wr      %g1, %tbr               ! Traps are at reset_vector

        nop

        nop

        nop

#ifdef CYGHWR_HAL_SPARCLITE_HAS_ASR17

#ifdef CYGHWR_HAL_SPARCLITE_MULTIPLE_VECTOR_TRAPPING

        wr      %g0, 0, %asr17          ! Multiple vector trapping

#else

        wr      %g0, 1, %asr17          ! Single vector trapping

#endif // !CYGHWR_HAL_SPARCLITE_MULTIPLE_VECTOR_TRAPPING

#endif // CYGHWR_HAL_SPARCLITE_HAS_ASR17

        nop

        nop

        nop

// INCLUDE PLATFORM BOOT

// This should set up RAM and caches, and calm down any external interrupt

// sources.  Also copy two instructions from real_vector_instructions

// into reset_vector, then invalidate the instruction cache.

#include 

// halboot.si returns with %sp all set, in sleb versions.

// (though we override if there is an interrupt stack)

        led     0x80

        ! now set up a stack and initial frame linkage

        ! so as to be able to make C function calls:

        ! current window is 7, the highest, so we store a

        ! saved frame thingy that refers to itself in the stack,

        ! then another which is valid and drop into main from there.

#ifdef BOOTUPSTACK_IS_INTERRUPTSTACK

        sethi   %hi(cyg_interrupt_stack), %i6

        or      %i6, %lo(cyg_interrupt_stack), %i6

#endif

        andn    %i6, 7, %i6             ! round fp down to double alignment

        mov     0, %i7                  ! null return address

        sethi   %hi(0xb51ac000), %i0    ! "BStac" pattern

        or      %i0, 24, %i0

        or      %i0, 1, %i1

        or      %i0, 2, %i2

        or      %i0, 3, %i3

        or      %i0, 4, %i4

        or      %i0, 5, %i5

        sethi   %hi(0xb51ac000), %l0    ! "BStac" pattern

        or      %l0, 16, %l0

        or      %l0, 1, %l1

        or      %l0, 2, %l2

        or      %l0, 3, %l3

        or      %l0, 4, %l4

        or      %l0, 5, %l5

        or      %l0, 6, %l6

        or      %l0, 7, %l7

        sub     %fp, 16 * 4, %sp        ! Stack pointer

        led     0x90

        std     %l0, [%sp + 0 * 4]      ! save L & I registers

        std     %l2, [%sp + 2 * 4]      ! into new stack frame

        std     %l4, [%sp + 4 * 4]

        std     %l6, [%sp + 6 * 4]

        led     0x91

        std     %i0, [%sp + 8 * 4]

        std     %i2, [%sp + 10 * 4]

        std     %i4, [%sp + 12 * 4]

        std     %i6, [%sp + 14 * 4]

        led     0x92

        sethi   %hi(0xb0010000), %o0    ! "Boot" pattern

        or      %o0, 8, %o0

        or      %o0, 1, %o1

        or      %o0, 2, %o2

        or      %o0, 3, %o3

        or      %o0, 4, %o4

        or      %o0, 5, %o5

        led     0x98

        wr      %g0, __WIM_INIT, %wim   ! Window 7 (current) is invalid

        nop

        nop

        nop

        led     0x99

        sethi   %hi(0xb0010000), %g1    ! "Boot" pattern

        or      %g1, 2, %g2

        or      %g1, 3, %g3

        or      %g1, 4, %g4

        or      %g1, 5, %g5

        or      %g1, 6, %g6

        or      %g1, 7, %g7

        or      %g1, 1, %g1

        led     0xa0

        wr      %g0, 0xfe0 + __WIN_INIT, %psr

        nop                             ! Enable traps:

        nop                             ! set psr, _do_ mask interrupts

        nop                             ! mode = prevMode = S, CWP=7

        led     0xb0

        ! now we can start calling out and running C code!

        .extern cyg_hal_start

        call    cyg_hal_start           ! puts return address in %o7

        or      %g1, 1, %g1

loop_forever:

        ta      1

        b       loop_forever            ! if it returns

        nop

!---------------------------------------------------------------------------

! hal_vsr_table...

        .section ".data"

        .balign 4

        .global hal_vsr_table

hal_vsr_table:

        .rept 16

        .word hal_default_interrupt_vsr

        .endr

        .rept 11

        .word hal_default_exception_vsr

        .endr

!---------------------------------------------------------------------------

! Bootup stack (only needed explicitly in sim)

#ifdef BOOTUPSTACK_IS_INTERRUPTSTACK

        .section ".bss"

#ifndef CYGNUM_HAL_COMMON_INTERRUPTS_STACK_SIZE

#define CYGNUM_HAL_COMMON_INTERRUPTS_STACK_SIZE 4096

#endif

        .balign 16

        .global cyg_interrupt_stack_base

cyg_interrupt_stack_base:

        .rept CYGNUM_HAL_COMMON_INTERRUPTS_STACK_SIZE

        .byte 0

        .endr

        .balign 16

        .global cyg_interrupt_stack

cyg_interrupt_stack:

        .long   0,0,0,0,0,0,0,0         ! here be secret state stored

#endif

!------------------------------------------------------------------------

! Define a section that reserves space at the start of RAM for the

! vectors to be copied into, for ROM start only.

        .section ".ram_vectors","awx",@nobits

#ifdef CYGIMP_HAL_SPARCLITE_COPY_VECTORS_TO_RAM

        ! need a space at base of RAM for copied vector/trampoline code

        .align 0x1000

        .space 8                        ! for fencepost errors

        .space (rom_vectors_end - rom_vectors)

#endif // CYGIMP_HAL_SPARCLITE_COPY_VECTORS_TO_RAM

!------------------------------------------------------------------------

! end of vectors.S