mirror of
https://github.com/rust-embedded/rust-raspberrypi-OS-tutorials.git
synced 2024-11-17 21:25:52 +00:00
56 lines
1.7 KiB
ArmAsm
56 lines
1.7 KiB
ArmAsm
/*
|
|
* Copyright (C) 2018 bzt (bztsrc@github)
|
|
*
|
|
* Permission is hereby granted, free of charge, to any person
|
|
* obtaining a copy of this software and associated documentation
|
|
* files (the "Software"), to deal in the Software without
|
|
* restriction, including without limitation the rights to use, copy,
|
|
* modify, merge, publish, distribute, sublicense, and/or sell copies
|
|
* of the Software, and to permit persons to whom the Software is
|
|
* furnished to do so, subject to the following conditions:
|
|
*
|
|
* The above copyright notice and this permission notice shall be
|
|
* included in all copies or substantial portions of the Software.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
|
|
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
|
|
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
|
|
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
|
|
* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
|
|
* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
|
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
|
|
* DEALINGS IN THE SOFTWARE.
|
|
*
|
|
*/
|
|
|
|
.section ".text.boot"
|
|
|
|
.global _start
|
|
|
|
_start:
|
|
// read cpu id, stop slave cores
|
|
mrs x1, mpidr_el1
|
|
and x1, x1, #3
|
|
cbz x1, 2f
|
|
// cpu id > 0, stop
|
|
1: wfe
|
|
b 1b
|
|
2: // cpu id == 0
|
|
|
|
// set stack before our code
|
|
ldr x1, =_start
|
|
mov sp, x1
|
|
|
|
// clear bss
|
|
ldr x1, =__bss_start
|
|
ldr w2, =__bss_size
|
|
3: cbz w2, 4f
|
|
str xzr, [x1], #8
|
|
sub w2, w2, #1
|
|
cbnz w2, 3b
|
|
|
|
// jump to C code, should not return
|
|
4: bl main
|
|
// for failsafe, halt this core too
|
|
b 1b
|