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/*
* 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.
*/
/* Exception handlers - Must be 32 bytes long. */
.section .text, "ax", @progbits
.global _start
.include "./csr-opcodes.h"
_start:
_reset_handler:
xor r0, r0, r0
wcsr IE, r0
mvhi r1, hi(_reset_handler)
ori r1, r1, lo(_reset_handler)
wcsr EBA, r1
xor r2, r2, r2
bi _crt0
nop
_breakpoint_handler:
bi _breakpoint_handler
nop
nop
nop
nop
nop
nop
nop
_instruction_bus_error_handler:
bi _instruction_bus_error_handler
nop
nop
nop
nop
nop
nop
nop
_watchpoint_hander:
bi _watchpoint_hander
nop
nop
nop
nop
nop
nop
nop
_data_bus_error_handler:
bi _data_bus_error_handler
nop
nop
nop
nop
nop
nop
nop
_divide_by_zero_handler:
bi _divide_by_zero_handler
nop
nop
nop
nop
nop
nop
nop
_interrupt_handler:
sw (sp+0), ra
calli .save_all
calli isr
bi .restore_all_and_eret
nop
nop
nop
nop
_scall_handler:
bi _scall_handler
nop
nop
nop
nop
nop
nop
nop
_dtlb_miss_exception_handler:
sw (sp+0), ra
addi ea, ea, -4
calli .save_all
calli dtlb_miss_handler
bi .restore_all_and_eret
nop
nop
nop
_itlb_miss_exception_handler:
sw (sp+0), ra
calli .save_all
calli itlb_miss_handler
bi .restore_all_and_eret
nop
nop
nop
nop
macaddress:
.byte 0x10
.byte 0xe2
.byte 0xd5
.byte 0x00
.byte 0x00
.byte 0x00
/* padding to align to a 32-bit boundary */
.byte 0x00
.byte 0x00
_crt0:
mvi r3, 1
mvi r2, 0xdf
/* give time for DTLB to flush itself */
loop:
nop
sub r2, r2, r3
bne r2, r0, loop
/* Setup stack and global pointer */
mvhi sp, hi(_fstack)
ori sp, sp, lo(_fstack)
mvhi gp, hi(_gp)
ori gp, gp, lo(_gp)
/* Clear BSS */
mvhi r1, hi(_fbss)
ori r1, r1, lo(_fbss)
mvhi r3, hi(_ebss)
ori r3, r3, lo(_ebss)
.clearBSS:
be r1, r3, .callMain
sw (r1+0), r0
addi r1, r1, 4
bi .clearBSS
.callMain:
mv r1, r2
mvi r2, 0
mvi r3, 0
bi main
.save_all:
addi sp, sp, -56
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
sw (sp+48), ea
sw (sp+52), ba
/* ra needs to be moved from initial stack location */
lw r1, (sp+56)
sw (sp+44), r1
ret
.restore_all_and_eret:
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)
lw ra, (sp+44)
lw ea, (sp+48)
lw ba, (sp+52)
addi sp, sp, 56
eret
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