arch/arm/cpu/armv8/start.S

   1 /*
   2  * (C) Copyright 2013
   3  * David Feng <[email protected]>
   4  *
   5  * SPDX-License-Identifier:     GPL-2.0+
   6  */
   7
   8 #include <asm-offsets.h>
   9 #include <config.h>
  10 #include <version.h>
  11 #include <linux/linkage.h>
  12 #include <asm/macro.h>
  13 #include <asm/armv8/mmu.h>
  14
  15 /*************************************************************************
  16  *
  17  * Startup Code (reset vector)
  18  *
  19  *************************************************************************/
  20
  21 .globl  _start
  22 _start:
  23         b       reset
  24
  25         .align 3
  26
  27 .globl  _TEXT_BASE
  28 _TEXT_BASE:
  29         .quad   CONFIG_SYS_TEXT_BASE
  30
  31 /*
  32  * These are defined in the linker script.
  33  */
  34 .globl  _end_ofs
  35 _end_ofs:
  36         .quad   _end - _start
  37
  38 .globl  _bss_start_ofs
  39 _bss_start_ofs:
  40         .quad   __bss_start - _start
  41
  42 .globl  _bss_end_ofs
  43 _bss_end_ofs:
  44         .quad   __bss_end - _start
  45
  46 reset:
  47         /*
  48          * Could be EL3/EL2/EL1, Initial State:
  49          * Little Endian, MMU Disabled, i/dCache Disabled
  50          */
  51         adr     x0, vectors
  52         switch_el x1, 3f, 2f, 1f
  53 3:      msr     vbar_el3, x0
  54         msr     cptr_el3, xzr                   /* Enable FP/SIMD */
  55         ldr     x0, =COUNTER_FREQUENCY
  56         msr     cntfrq_el0, x0                  /* Initialize CNTFRQ */
  57         b       0f
  58 2:      msr     vbar_el2, x0
  59         mov     x0, #0x33ff
  60         msr     cptr_el2, x0                    /* Enable FP/SIMD */
  61         b       0f
  62 1:      msr     vbar_el1, x0
  63         mov     x0, #3 << 20
  64         msr     cpacr_el1, x0                   /* Enable FP/SIMD */
  65 0:
  66
  67         /* Cache/BPB/TLB Invalidate */
  68         bl      __asm_flush_dcache_all          /* dCache clean&invalidate */
  69         bl      __asm_invalidate_icache_all     /* iCache invalidate */
  70         bl      __asm_invalidate_tlb_all        /* invalidate TLBs */
  71
  72         /* Processor specific initialization */
  73         bl      lowlevel_init
  74
  75         branch_if_master x0, x1, master_cpu
  76
  77         /*
  78          * Slave CPUs
  79          */
  80 slave_cpu:
  81         wfe
  82         ldr     x1, =CPU_RELEASE_ADDR
  83         ldr     x0, [x1]
  84         cbz     x0, slave_cpu
  85         br      x0                      /* branch to the given address */
  86
  87         /*
  88          * Master CPU
  89          */
  90 master_cpu:
  91         bl      _main
  92
  93 /*-----------------------------------------------------------------------*/
  94
  95 WEAK(lowlevel_init)
  96         /* Initialize GIC Secure Bank Status */
  97         mov     x29, lr                 /* Save LR */
  98         bl      gic_init
  99
 100         branch_if_master x0, x1, 1f
 101
 102         /*
 103          * Slave should wait for master clearing spin table.
 104          * This sync prevent salves observing incorrect
 105          * value of spin table and jumping to wrong place.
 106          */
 107         bl      wait_for_wakeup
 108
 109         /*
 110          * All processors will enter EL2 and optionally EL1.
 111          */
 112         bl      armv8_switch_to_el2
 113 #ifdef CONFIG_ARMV8_SWITCH_TO_EL1
 114         bl      armv8_switch_to_el1
 115 #endif
 116
 117 1:
 118         mov     lr, x29                 /* Restore LR */
 119         ret
 120 ENDPROC(lowlevel_init)
 121
 122 /*-----------------------------------------------------------------------*/
 123
 124 ENTRY(c_runtime_cpu_setup)
 125         /* If I-cache is enabled invalidate it */
 126 #ifndef CONFIG_SYS_ICACHE_OFF
 127         ic      iallu                   /* I+BTB cache invalidate */
 128         isb     sy
 129 #endif
 130
 131         /* Relocate vBAR */
 132         adr     x0, vectors
 133         switch_el x1, 3f, 2f, 1f
 134 3:      msr     vbar_el3, x0
 135         b       0f
 136 2:      msr     vbar_el2, x0
 137         b       0f
 138 1:      msr     vbar_el1, x0
 139 0:
 140
 141         ret
 142 ENDPROC(c_runtime_cpu_setup)