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Wesley W. Terpstra authored
When linked against debug.S, which provides this symbol, this will setup debugging. If not linked against debug.S the symbol will be the same as _reset_handler.
329f0bd9
crt0.S 8.00 KiB
/****************************************************************************
**
** Name: crt0ram.S
**
** Description:
** Implements boot-code that calls LatticeDDInit (that calls main())
** Implements exception handlers (actually, redirectors)
**
** $Revision: $
**
** Disclaimer:
**
** This source code is intended as a design reference which
** illustrates how these types of functions can be implemented. It
** is the user's responsibility to verify their design for
** consistency and functionality through the use of formal
** verification methods. Lattice Semiconductor provides no warranty
** regarding the use or functionality of this code.
**
** --------------------------------------------------------------------
**
** Lattice Semiconductor Corporation
** 5555 NE Moore Court
** Hillsboro, OR 97214
** U.S.A
**
** TEL: 1-800-Lattice (USA and Canada)
** (503)268-8001 (other locations)
**
** web: http://www.latticesemi.com
** email: techsupport@latticesemi.com
**
** --------------------------------------------------------------------------
**
** Change History (Latest changes on top)
**
** Ver Date Description
** --------------------------------------------------------------------------
** 3.8 Apr-15-2011 Added __MICO_USER_<handler>_HANDLER__ preprocessor to
** allow customers to implement their own handlers for:
** DATA_ABORT, INST_ABORT
**
** 3.1 Jun-18-2008 Added __MICO_NO_INTERRUPTS__ preprocessor
** option to exclude invoking MicoISRHandler
** to reduce code-size in apps that don't use
** interrupts
**
** 3.0 Mar-25-2008 Added Header
**
**---------------------------------------------------------------------------
*****************************************************************************/
/*
* LatticeMico32 C startup code.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/* From include/sys/signal.h */
#define SIGINT 2 /* interrupt */
#define SIGTRAP 5 /* trace trap */
#define SIGFPE 8 /* arithmetic exception */
#define SIGSEGV 11 /* segmentation violation */
//#define MICO32_FULL_CONTEXT_SAVE_RESTORE
/* Exception handlers - Must be 32 bytes long. */
.section .boot, "ax", @progbits
.global _start
.weak _debug_unit
_start:
_debug_unit:
.global _reset_handler
.type _reset_handler, @function
_reset_handler:
xor r0, r0, r0
wcsr IE, r0
wcsr IM, r0
mvhi r1, hi(_reset_handler)
ori r1, r1, lo(_reset_handler)
wcsr EBA, r1
calli _crt0
nop
.size _reset_handler, .-_reset_handler
.extern _irq_entry
.org 0xc0
.global _interrupt_handler
.type _interrupt_handler, @function
_interrupt_handler:
sw (sp+0), ra
calli _save_all
mvi r1, SIGINT
#ifndef __MICO_NO_INTERRUPTS__
calli _irq_entry
#else
wcsr IE, r0
#endif
bi _restore_all_and_return
nop
nop
nop
.org 0x100
.global _crt0
.type _crt0, @function
_crt0:
/* Clear r0 */
xor r0, r0, r0
/* Setup the debug ROM if it's linked in */
mvhi r1, hi(_debug_unit)
ori r1, r1, lo(_debug_unit)
wcsr DEBA
/* Setup stack and global pointer */
mvhi sp, hi(_fstack)
ori sp, sp, lo(_fstack)
mvhi gp, hi(_gp) ori gp, gp, lo(_gp)
mvhi r1, hi(_fbss)
ori r1, r1, lo(_fbss)
mvi r2, 0
mvhi r3, hi(_ebss)
ori r3, r3, lo(_ebss)
sub r3, r3, r1
calli memset
mvi r1, 0
mvi r2, 0
mvi r3, 0
calli main
loopf:
bi loopf
.global _save_all
.type _save_all, @function
_save_all:
#ifdef MICO32_FULL_CONTEXT_SAVE_RESTORE
addi sp, sp, -128
#else
addi sp, sp, -60
#endif
sw (sp+4), r1
sw (sp+8), r2
sw (sp+12), r3
sw (sp+16), r4
sw (sp+20), r5
sw (sp+24), r6
sw (sp+28), r7
sw (sp+32), r8
sw (sp+36), r9
sw (sp+40), r10
#ifdef MICO32_FULL_CONTEXT_SAVE_RESTORE
sw (sp+44), r11
sw (sp+48), r12
sw (sp+52), r13
sw (sp+56), r14
sw (sp+60), r15
sw (sp+64), r16
sw (sp+68), r17
sw (sp+72), r18
sw (sp+76), r19
sw (sp+80), r20
sw (sp+84), r21
sw (sp+88), r22
sw (sp+92), r23
sw (sp+96), r24
sw (sp+100), r25
sw (sp+104), r26
sw (sp+108), r27
sw (sp+120), ea
sw (sp+124), ba
/* ra and sp need special handling, as they have been modified */
lw r1, (sp+128)
sw (sp+116), r1
mv r1, sp
addi r1, r1, 128
sw (sp+112), r1
#else
sw (sp+52), ea
sw (sp+56), ba
/* ra and sp need special handling, as they have been modified */
lw r1, (sp+60)
sw (sp+48), r1
mv r1, sp
addi r1, r1, 60
sw (sp+44), r1#endif
// xor r1, r1, r1
// wcsr ie, r1
ret
.size _save_all, .-_save_all
.global _restore_all_and_return
.type _restore_all_and_return, @function
/* Restore all registers and return from exception */
_restore_all_and_return:
// addi r1, r0, 2
// wcsr ie, r1
lw r1, (sp+4)
lw r2, (sp+8)
lw r3, (sp+12)
lw r4, (sp+16)
lw r5, (sp+20)
lw r6, (sp+24)
lw r7, (sp+28)
lw r8, (sp+32)
lw r9, (sp+36)
lw r10, (sp+40)
#ifdef MICO32_FULL_CONTEXT_SAVE_RESTORE
lw r11, (sp+44)
lw r12, (sp+48)
lw r13, (sp+52)
lw r14, (sp+56)
lw r15, (sp+60)
lw r16, (sp+64)
lw r17, (sp+68)
lw r18, (sp+72)
lw r19, (sp+76)
lw r20, (sp+80)
lw r21, (sp+84)
lw r22, (sp+88)
lw r23, (sp+92)
lw r24, (sp+96)
lw r25, (sp+100)
lw r26, (sp+104)
lw r27, (sp+108)
lw ra, (sp+116)
lw ea, (sp+120)
lw ba, (sp+124)
/* Stack pointer must be restored last, in case it has been updated */
lw sp, (sp+112)
#else
lw ra, (sp+48)
lw ea, (sp+52)
lw ba, (sp+56)
/* Stack pointer must be restored last, in case it has been updated */
lw sp, (sp+44)
#endif
nop
eret
.size _restore_all_and_return, .-_restore_all_and_return