circuitpython/ports/mimxrt/hal/resethandler_MIMXRT10xx.S

176 lines
5.6 KiB
ArmAsm

/* ------------------------------------------------------------------------- */
/* */
/* Copyright 1997-2016 Freescale Semiconductor, Inc. */
/* Copyright 2016-2019 NXP */
/* All rights reserved. */
/* */
/* SPDX-License-Identifier: BSD-3-Clause */
/*****************************************************************************/
/* Version: GCC for ARM Embedded Processors */
/*****************************************************************************/
.syntax unified
.arch armv7-m
#include"flexram_config.s"
/* Reset Handler */
.thumb_func
.align 2
.globl Reset_Handler
.type Reset_Handler, %function
Reset_Handler:
cpsid i /* Mask interrupts */
.equ VTOR, 0xE000ED08
ldr r0, =VTOR
ldr r1, =__isr_vector
str r1, [r0]
ldr r2, [r1]
msr msp, r2
/* Reconfigure the memory map, which must match the setting of the linker script */
dsb
isb
ldr r0, =__iomux_gpr17_adr /* load IOMUXC_GPR17 register address to R0 */
ldr r1, =__iomux_gpr17_value /* move FlexRAM configuration value to R1 */
str r1,[r0] /* store FLEXRAM configuration value to IOMUXC_GPR17 */
dsb
isb
ldr r0, =__iomux_gpr16_adr /* load IOMUXC_GPR16 register address to R0 */
ldr r1,[r0] /* load IOMUXC_GPR16 register value to R1 */
orr r1, r1, #4 /* set corresponding FLEXRAM_BANK_CFG_SEL bit */
str r1,[r0] /* store the value to IOMUXC_GPR16 (FLEXRAM_BANK_CFG_SEL = '1') */
dsb
isb
#ifndef __NO_SYSTEM_INIT
ldr r0,=SystemInit
blx r0
#endif
/* Loop to copy data from read only memory to RAM. The ranges
* of copy from/to are specified by following symbols evaluated in
* linker script.
* __etext: End of code section, i.e., begin of data sections to copy from.
* __data_start__/__data_end__: RAM address range that data should be
* __noncachedata_start__/__noncachedata_end__ : none cachable region
* __ram_function_start__/__ram_function_end__ : ramfunction region
* copied to. Both must be aligned to 4 bytes boundary. */
ldr r1, =__etext
ldr r2, =__data_start__
ldr r3, =__data_end__
#ifdef __PERFORMANCE_IMPLEMENTATION
/* Here are two copies of loop implementations. First one favors performance
* and the second one favors code size. Default uses the second one.
* Define macro "__PERFORMANCE_IMPLEMENTATION" in project to use the first one */
subs r3, r2
ble .LC1
.LC0:
subs r3, #4
ldr r0, [r1, r3]
str r0, [r2, r3]
bgt .LC0
.LC1:
#else /* code size implemenation */
.LC0:
cmp r2, r3
ittt lt
ldrlt r0, [r1], #4
strlt r0, [r2], #4
blt .LC0
#endif
#ifdef __STARTUP_INITIALIZE_RAMFUNCTION
ldr r2, =__ram_function_start__
ldr r3, =__ram_function_end__
#ifdef __PERFORMANCE_IMPLEMENTATION
/* Here are two copies of loop implementations. First one favors performance
* and the second one favors code size. Default uses the second one.
* Define macro "__PERFORMANCE_IMPLEMENTATION" in project to use the first one */
subs r3, r2
ble .LC_ramfunc_copy_end
.LC_ramfunc_copy_start:
subs r3, #4
ldr r0, [r1, r3]
str r0, [r2, r3]
bgt .LC_ramfunc_copy_start
.LC_ramfunc_copy_end:
#else /* code size implemenation */
.LC_ramfunc_copy_start:
cmp r2, r3
ittt lt
ldrlt r0, [r1], #4
strlt r0, [r2], #4
blt .LC_ramfunc_copy_start
#endif
#endif /* __STARTUP_INITIALIZE_RAMFUNCTION */
#ifdef __STARTUP_INITIALIZE_NONCACHEDATA
ldr r2, =__noncachedata_start__
ldr r3, =__noncachedata_init_end__
#ifdef __PERFORMANCE_IMPLEMENTATION
/* Here are two copies of loop implementations. First one favors performance
* and the second one favors code size. Default uses the second one.
* Define macro "__PERFORMANCE_IMPLEMENTATION" in project to use the first one */
subs r3, r2
ble .LC3
.LC2:
subs r3, #4
ldr r0, [r1, r3]
str r0, [r2, r3]
bgt .LC2
.LC3:
#else /* code size implemenation */
.LC2:
cmp r2, r3
ittt lt
ldrlt r0, [r1], #4
strlt r0, [r2], #4
blt .LC2
#endif
/* zero inited ncache section initialization */
ldr r3, =__noncachedata_end__
movs r0,0
.LC4:
cmp r2,r3
itt lt
strlt r0,[r2],#4
blt .LC4
#endif /* __STARTUP_INITIALIZE_NONCACHEDATA */
#ifdef __STARTUP_CLEAR_BSS
/* This part of work usually is done in C library startup code. Otherwise,
* define this macro to enable it in this startup.
*
* Loop to zero out BSS section, which uses following symbols
* in linker script:
* __bss_start__: start of BSS section. Must align to 4
* __bss_end__: end of BSS section. Must align to 4
*/
ldr r1, =__bss_start__
ldr r2, =__bss_end__
movs r0, 0
.LC5:
cmp r1, r2
itt lt
strlt r0, [r1], #4
blt .LC5
#endif /* __STARTUP_CLEAR_BSS */
cpsie i /* Unmask interrupts */
#ifndef __START
#define __START _start
#endif
#ifndef __ATOLLIC__
ldr r0,=__START
blx r0
#else
ldr r0,=__libc_init_array
blx r0
ldr r0,=main
bx r0
#endif
.pool
.size Reset_Handler, . - Reset_Handler