zephyr/soc/nxp/lpc/lpc54xxx/gcc/startup_LPC54114_cm4.S

104 lines
3.3 KiB
ArmAsm

/*
* Copyright (c) 2016, Freescale Semiconductor, Inc.
* Copyright 2016 - 2019 , NXP
* All rights reserved.
*
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <zephyr/toolchain.h>
#include <zephyr/linker/sections.h>
#include <zephyr/arch/cpu.h>
#if defined(CONFIG_PLATFORM_SPECIFIC_INIT) && defined(CONFIG_SOC_LPC54114_M4)
.syntax unified
.arch armv7-m
.text
.thumb
rel_vals:
.long 0xE000ED00 /* cpu_id */
.long 0x40000800 /* cpu_ctrl */
.long 0x40000804 /* coproc_boot */
.long 0x40000808 /* coproc_stack */
.short 0x0FFF
.short 0x0C24
GTEXT(z_arm_platform_init)
SECTION_FUNC(TEXT,z_arm_platform_init)
/* Both the M0+ and M4 core come via this shared startup code,
* but the M0+ and M4 core have different vector tables.
* Determine if the core executing this code is the master or
* the slave and handle each core state individually. */
shared_boot_entry:
ldr r6, =rel_vals
/* Flag for slave core (0) */
movs r4, 0
movs r5, 1
push {lr}
bl SystemInit
pop {lr}
/* Determine which core (M0+ or M4) this code is running on */
/* r2 = (((*cpu_id) >> 4) & 0xFFF); (M4 core == 0xC24) */
get_current_core_id:
ldr r0, [r6, #0]
ldr r1, [r0] /* r1 = CPU ID status */
lsrs r1, r1, #4 /* Right justify 12 CPU ID bits */
ldrh r2, [r6, #16] /* Mask for CPU ID bits */
ands r2, r1, r2 /* r2 = ARM COrtex CPU ID */
ldrh r3, [r6, #18] /* Mask for CPU ID bits */
cmp r3, r2 /* Core ID matches M4 identifier */
bne get_master_status
mov r4, r5 /* Set flag for master core (1) */
/* Determine if M4 core is the master or slave */
/* r3 = ((*cpu_ctrl) & 1); (0 == m0+, 1 == M4) */
get_master_status:
ldr r0, [r6, #4]
ldr r3, [r0] /* r3 = SYSCON co-processor CPU control status */
ands r3, r3, r5 /* r3 = (Bit 0: 1 = M4 is master, 0 = M4 is slave) */
/* Select boot based on selected master core and core ID */
select_boot:
eors r3, r3, r4 /* r4 = (Bit 0: 0 = master, 1 = slave) */
bne slave_boot
b normal_boot
/* Slave boot */
slave_boot:
ldr r0, [r6, #8]
ldr r2, [r0] /* r1 = SYSCON co-processor boot address */
cmp r2, #0 /* Slave boot address = 0 (not set up)? */
beq cpu_sleep
ldr r0, [r6, #12]
ldr r1, [r0] /* r5 = SYSCON co-processor stack address */
mov sp, r1 /* Update slave CPU stack pointer */
/* Be sure to update VTOR for the slave MCU to point to the */
/* slave vector table in boot memory */
bx r2 /* Jump to slave boot address */
/* Slave isn't yet setup for system boot from the master */
/* so sleep until the master sets it up and then reboots it */
cpu_sleep:
mov sp, r5 /* Will force exception if something happens */
cpu_sleep_wfi:
wfi /* Sleep forever until master reboots */
b cpu_sleep_wfi
normal_boot:
bx lr
#endif