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/*
* Copyright (c) 2006-2020, RT-Thread Development Team
*
* SPDX-License-Identifier: Apache-2.0
*
* Date Author Notes
* 2020-01-15 bigmagic the first version
* 2020-08-10 SummerGift support clang compiler
*/
#include "rtconfig.h"
.section ".text.entrypoint","ax"
.global __start
__start:
#ifdef ARCH_ARM_BOOTWITH_FLUSH_CACHE
bl __asm_flush_dcache_all
#endif
bl rt_hw_cpu_id_set
/* read cpu id, stop slave cores */
mrs x0, tpidr_el1
cbz x0, .L__cpu_0 /* .L prefix is the local label in ELF */
/* cpu id > 0, stop */
/* cpu id == 0 will also goto here after returned from entry() if possible */
.L__current_cpu_idle:
wfe
b .L__current_cpu_idle
.L__cpu_0:
/* set stack before our code, Define stack pointer for current exception level */
adr x1, __start
/* set up EL1 */
mrs x0, CurrentEL /* CurrentEL Register. bit 2, 3. Others reserved */
and x0, x0, #12 /* clear reserved bits */
/* running at EL3? */
cmp x0, #12 /* 1100b. So, EL3 */
bne .L__not_in_el3 /* 11? !EL3 -> 5: */
/* should never be executed, just for completeness. (EL3) */
mov x2, #0x5b1
msr scr_el3, x2 /* SCR_ELn Secure Configuration Register */
mov x2, #0x3c9
msr spsr_el3, x2 /* SPSR_ELn. Saved Program Status Register. 1111001001 */
adr x2, .L__not_in_el3
msr elr_el3, x2
eret /* Exception Return: from EL3, continue from .L__not_in_el3 */
.L__not_in_el3: /* running at EL2 or EL1 */
cmp x0, #4 /* 0x04 0100 EL1 */
beq .L__in_el1 /* EL1 -> 5: */
mrs x0, hcr_el2
bic x0, x0, #0xff
msr hcr_el2, x0
msr sp_el1, x1 /* in EL2, set sp of EL1 to _start */
/* enable CNTP for EL1 */
mrs x0, cnthctl_el2 /* Counter-timer Hypervisor Control register */
orr x0, x0, #3
msr cnthctl_el2, x0
msr cntvoff_el2, xzr
/* enable AArch64 in EL1 */
mov x0, #(1 << 31) /* AArch64 */
orr x0, x0, #(1 << 1) /* SWIO hardwired on Pi3 */
msr hcr_el2, x0
mrs x0, hcr_el2
/* change execution level to EL1 */
mov x2, #0x3c4
msr spsr_el2, x2 /* 1111000100 */
adr x2, .L__in_el1
msr elr_el2, x2
eret /* exception return. from EL2. continue from .L__in_el1 */
.macro GET_PHY reg, symbol
adrp \reg, \symbol
add \reg, \reg, #:lo12:\symbol
.endm
.L__in_el1:
mov sp, x1 /* in EL1. Set sp to _start */
/* Set CPACR_EL1 (Architecture Feature Access Control Register) to avoid trap from SIMD or float point instruction */
mov x1, #0x00300000 /* Don't trap any SIMD/FP instructions in both EL0 and EL1 */
msr cpacr_el1, x1
/* applying context change */
dsb ish
isb
/* clear bss */
GET_PHY x1, __bss_start
GET_PHY x2, __bss_end
sub x2, x2, x1 /* get bss size */
and x3, x2, #7 /* x3 is < 7 */
ldr x4, =~0x7
and x2, x2, x4 /* mask ~7 */
.L__clean_bss_loop:
cbz x2, .L__clean_bss_loop_1
str xzr, [x1], #8
sub x2, x2, #8
b .L__clean_bss_loop
.L__clean_bss_loop_1:
cbz x3, .L__jump_to_entry
strb wzr, [x1], #1
sub x3, x3, #1
b .L__clean_bss_loop_1
.L__jump_to_entry: /* jump to C code, should not return */
bl mmu_tcr_init
adr x1, __start /* install early page table */
ldr x0, =~0x1fffff
and x0, x1, x0
add x1, x0, #0x1000
msr ttbr0_el1, x0
msr ttbr1_el1, x1
dsb sy
#ifdef RT_USING_SMART
ldr x2, =__start
GET_PHY x3, __start
sub x3, x3, x2
#endif
ldr x2, =0x40000000 /* map 1G memory for kernel space */
bl rt_hw_mem_setup_early
ldr x30, =after_mmu_enable /* set LR to after_mmu_enable function, it's a v_addr */
mrs x1, sctlr_el1
bic x1, x1, #(3 << 3) /* dis SA, SA0 */
bic x1, x1, #(1 << 1) /* dis A */
orr x1, x1, #(1 << 12) /* I */
orr x1, x1, #(1 << 2) /* C */
orr x1, x1, #(1 << 0) /* M */
msr sctlr_el1, x1 /* enable MMU */
dsb ish
isb
ic ialluis /* Invalidate all instruction caches in Inner Shareable domain to Point of Unification */
dsb ish
isb
tlbi vmalle1 /* Invalidate all stage 1 translations used at EL1 with the current VMID */
dsb ish
isb
ret
after_mmu_enable:
#ifdef RT_USING_SMART
mrs x0, tcr_el1 /* disable ttbr0, only using kernel space */
orr x0, x0, #(1 << 7)
msr tcr_el1, x0
msr ttbr0_el1, xzr
dsb sy
#endif
mov x0, #1
msr spsel, x0
adr x1, __start
mov sp, x1 /* sp_el1 set to _start */
b rtthread_startup
#ifdef RT_USING_SMP
/**
* secondary cpu
*/
.global _secondary_cpu_entry
_secondary_cpu_entry:
bl rt_hw_cpu_id_set
adr x1, __start
/* set up EL1 */
mrs x0, CurrentEL /* CurrentEL Register. bit 2, 3. Others reserved */
and x0, x0, #12 /* clear reserved bits */
/* running at EL3? */
cmp x0, #12 /* 1100b. So, EL3 */
bne .L__not_in_el3_cpux /* 11? !EL3 -> 5: */
/* should never be executed, just for completeness. (EL3) */
mov x2, #0x5b1
msr scr_el3, x2 /* SCR_ELn Secure Configuration Register */
mov x2, #0x3c9
msr spsr_el3, x2 /* SPSR_ELn. Saved Program Status Register. 1111001001 */
adr x2, .L__not_in_el3_cpux
msr elr_el3, x2
eret /* Exception Return: from EL3, continue from .L__not_in_el3 */
.L__not_in_el3_cpux: /* running at EL2 or EL1 */
cmp x0, #4 /* 0x04 0100 EL1 */
beq .L__in_el1_cpux /* EL1 -> 5: */
mrs x0, hcr_el2
bic x0, x0, #0xff
msr hcr_el2, x0
msr sp_el1, x1 /* in EL2, set sp of EL1 to _start */
/* enable CNTP for EL1 */
mrs x0, cnthctl_el2 /* Counter-timer Hypervisor Control register */
orr x0, x0, #3
msr cnthctl_el2, x0
msr cntvoff_el2, xzr
/* enable AArch64 in EL1 */
mov x0, #(1 << 31) /* AArch64 */
orr x0, x0, #(1 << 1) /* SWIO hardwired on Pi3 */
msr hcr_el2, x0
mrs x0, hcr_el2
/* change execution level to EL1 */
mov x2, #0x3c4
msr spsr_el2, x2 /* 1111000100 */
adr x2, .L__in_el1_cpux
msr elr_el2, x2
eret /* exception return. from EL2. continue from .L__in_el1 */
.L__in_el1_cpux:
mrs x0, tpidr_el1
/* each cpu init stack is 8k */
sub x1, x1, x0, lsl #13
mov sp, x1 /* in EL1. Set sp to _start */
/* Set CPACR_EL1 (Architecture Feature Access Control Register) to avoid trap from SIMD or float point instruction */
mov x1, #0x00300000 /* Don't trap any SIMD/FP instructions in both EL0 and EL1 */
msr cpacr_el1, x1
.L__jump_to_entry_cpux: /* jump to C code, should not return */
/* init mmu early */
bl mmu_tcr_init
adr x1, __start /* GET & setup early page table */
ldr x0, =~0x1fffff
and x0, x1, x0
add x1, x0, #0x1000
msr ttbr0_el1, x0
msr ttbr1_el1, x1
dsb sy
ldr x30, =after_mmu_enable_cpux /* set LR to after_mmu_enable function, it's a v_addr */
mrs x1, sctlr_el1
bic x1, x1, #(3 << 3) /* dis SA, SA0 */
bic x1, x1, #(1 << 1) /* dis A */
orr x1, x1, #(1 << 12) /* I */
orr x1, x1, #(1 << 2) /* C */
orr x1, x1, #(1 << 0) /* M */
msr sctlr_el1, x1 /* enable MMU */
dsb sy
isb sy
ic ialluis /* Invalidate all instruction caches in Inner Shareable domain to Point of Unification */
dsb sy
isb sy
tlbi vmalle1 /* Invalidate all stage 1 translations used at EL1 with the current VMID */
dsb sy
isb sy
ret
after_mmu_enable_cpux:
#ifdef RT_USING_SMART
mrs x0, tcr_el1 /* disable ttbr0, only using kernel space */
orr x0, x0, #(1 << 7)
msr tcr_el1, x0
msr ttbr0_el1, xzr
dsb sy
#endif
mov x0, #1
msr spsel, x0
mrs x0, tpidr_el1
/* each cpu init stack is 8k */
adr x1, __start
sub x1, x1, x0, lsl #13
mov sp, x1 /* in EL1. Set sp to _start */
b rt_hw_secondary_cpu_bsp_start
#endif
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