arch/arm/lib/relocate_64.S

   1 /*
   2  * relocate - common relocation function for AArch64 U-Boot
   3  *
   4  * (C) Copyright 2013
   5  * Albert ARIBAUD <albert.u.boot@aribaud.net>
   6  * David Feng <fenghua@phytium.com.cn>
   7  *
   8  * SPDX-License-Identifier:     GPL-2.0+
   9  */
  10
  11 #include <asm-offsets.h>
  12 #include <config.h>
  13 #include <elf.h>
  14 #include <linux/linkage.h>
  15 #include <asm/macro.h>
  16
  17 /*
  18  * void relocate_code (addr_moni)
  19  *
  20  * This function relocates the monitor code.
  21  * x0 holds the destination address.
  22  */
  23 ENTRY(relocate_code)
  24         stp     x29, x30, [sp, #-32]!   /* create a stack frame */
  25         mov     x29, sp
  26         str     x0, [sp, #16]
  27         /*
  28          * Copy u-boot from flash to RAM
  29          */
  30         adr     x1, __image_copy_start  /* x1 <- Run &__image_copy_start */
  31         subs    x9, x0, x1              /* x8 <- Run to copy offset */
  32         b.eq    relocate_done           /* skip relocation */
  33         /*
  34          * Don't ldr x1, __image_copy_start here, since if the code is already
  35          * running at an address other than it was linked to, that instruction
  36          * will load the relocated value of __image_copy_start. To
  37          * correctly apply relocations, we need to know the linked value.
  38          *
  39          * Linked &__image_copy_start, which we know was at
  40          * CONFIG_SYS_TEXT_BASE, which is stored in _TEXT_BASE, as a non-
  41          * relocated value, since it isn't a symbol reference.
  42          */
  43         ldr     x1, _TEXT_BASE          /* x1 <- Linked &__image_copy_start */
  44         subs    x9, x0, x1              /* x9 <- Link to copy offset */
  45
  46         adr     x1, __image_copy_start  /* x1 <- Run &__image_copy_start */
  47         adr     x2, __image_copy_end    /* x2 <- Run &__image_copy_end */
  48 copy_loop:
  49         ldp     x10, x11, [x1], #16     /* copy from source address [x1] */
  50         stp     x10, x11, [x0], #16     /* copy to   target address [x0] */
  51         cmp     x1, x2                  /* until source end address [x2] */
  52         b.lo    copy_loop
  53         str     x0, [sp, #24]
  54
  55         /*
  56          * Fix .rela.dyn relocations
  57          */
  58         adr     x2, __rel_dyn_start     /* x2 <- Run &__rel_dyn_start */
  59         adr     x3, __rel_dyn_end       /* x3 <- Run &__rel_dyn_end */
  60 fixloop:
  61         ldp     x0, x1, [x2], #16       /* (x0,x1) <- (SRC location, fixup) */
  62         ldr     x4, [x2], #8            /* x4 <- addend */
  63         and     x1, x1, #0xffffffff
  64         cmp     x1, #R_AARCH64_RELATIVE
  65         bne     fixnext
  66
  67         /* relative fix: store addend plus offset at dest location */
  68         add     x0, x0, x9
  69         add     x4, x4, x9
  70         str     x4, [x0]
  71 fixnext:
  72         cmp     x2, x3
  73         b.lo    fixloop
  74
  75 relocate_done:
  76         switch_el x1, 3f, 2f, 1f
  77         bl      hang
  78 3:      mrs     x0, sctlr_el3
  79         b       0f
  80 2:      mrs     x0, sctlr_el2
  81         b       0f
  82 1:      mrs     x0, sctlr_el1
  83 0:      tbz     w0, #2, 5f      /* skip flushing cache if disabled */
  84         tbz     w0, #12, 4f     /* skip invalidating i-cache if disabled */
  85         ic      iallu           /* i-cache invalidate all */
  86         isb     sy
  87 4:      ldp     x0, x1, [sp, #16]
  88         bl      __asm_flush_dcache_range
  89 5:      ldp     x29, x30, [sp],#32
  90         ret
  91 ENDPROC(relocate_code)