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ossc/software/sys_controller/crt0.boot.S
2018-10-06 13:19:12 +03:00

104 lines
2.2 KiB
ArmAsm

// Copyright 2017 ETH Zurich and University of Bologna.
// Copyright and related rights are licensed under the Solderpad Hardware
// License, Version 0.51 (the License); you may not use this file except in
// compliance with the License. You may obtain a copy of the License at
// http://solderpad.org/licenses/SHL-0.51. Unless required by applicable law
// or agreed to in writing, software, hardware and materials distributed under
// this License is distributed on an AS IS BASIS, WITHOUT WARRANTIES OR
// CONDITIONS OF ANY KIND, either express or implied. See the License for the
// specific language governing permissions and limitations under the License.
#include "pulpino.h"
#define EXCEPTION_STACK_SIZE 72
/* ========================================================= [ entry ] === */
.section .text
default_exc_handler:
jal x0, default_exc_handler
reset_handler:
/* set all registers to zero */
mv x1, x0
mv x2, x1
mv x3, x1
mv x4, x1
mv x5, x1
mv x6, x1
mv x7, x1
mv x8, x1
mv x9, x1
mv x10, x1
mv x11, x1
mv x12, x1
mv x13, x1
mv x14, x1
mv x15, x1
mv x16, x1
mv x17, x1
mv x18, x1
mv x19, x1
mv x20, x1
mv x21, x1
mv x22, x1
mv x23, x1
mv x24, x1
mv x25, x1
mv x26, x1
mv x27, x1
mv x28, x1
mv x29, x1
mv x30, x1
mv x31, x1
/* stack initilization */
la x2, _stack_start
_start:
.global _start
/* clear BSS */
la x26, _bss_start
la x27, _bss_end
bge x26, x27, zero_loop_end
zero_loop:
sw x0, 0(x26)
addi x26, x26, 4
ble x26, x27, zero_loop
zero_loop_end:
main_entry:
/* jump to alt_main program entry point */
jal alt_main
/* =================================================== [ exceptions ] === */
/* This section has to be down here, since we have to disable rvc for it */
.section .vectors, "ax"
.option norvc;
// external interrupts are handled by the same callback
// until compiler supports IRQ routines
.org 0x00
.rept 31
nop
.endr
jal x0, default_exc_handler
// reset vector
.org 0x80
jal x0, reset_handler
// illegal instruction exception
.org 0x84
jal x0, default_exc_handler
// ecall handler
.org 0x88
jal x0, default_exc_handler