1 /*
   2  * This file and its contents are supplied under the terms of the
   3  * Common Development and Distribution License ("CDDL"), version 1.0.
   4  * You may only use this file in accordance with the terms of version
   5  * 1.0 of the CDDL.
   6  *
   7  * A full copy of the text of the CDDL should have accompanied this
   8  * source.  A copy of the CDDL is also available via the Internet at
   9  * http://www.illumos.org/license/CDDL.
  10  */
  11 
  12 /*
  13  * Copyright 2013 (c) Joyent, Inc. All rights reserved.
  14  * Copyright 2015 (c) Josef 'Jeff' Sipek <jeffpc@josefsipek.net>
  15  */
  16 
  17 /*
  18  * Every story needs a beginning, this is the loader's.
  19  */
  20 
  21 #include <sys/asm_linkage.h>
  22 
  23 /*
  24  * We put _start into the .text.init section so we can more easily shove it
  25  * at the front of the .text.
  26  */
  27         .section .text.init
  28         .align  4
  29         .globl  _start
  30         .type   _start, %function
  31 _start:
  32         mov     sp, #0x8000
  33         /*
  34          * XXX manually fix up the tag start
  35          */
  36         mov     r2, #0x100
  37         bl      fakeload_init
  38         SET_SIZE(_start)
  39 
  40 #if defined(__lint)
  41 
  42 /* ARGSUSED */
  43 void
  44 fakeload_unaligned_enable(void)
  45 {}
  46 
  47 #else   /* __lint */
  48 
  49         /*
  50          * Fix up alignment by turning off A and by turning on U.
  51          */
  52         ENTRY(fakeload_unaligned_enable)
  53         mrc     p15, 0, r0, c1, c0, 0
  54         orr     r0, #0x400000
  55         mcr     p15, 0, r0, c1, c0, 0
  56         bx      lr
  57         SET_SIZE(fakeload_unaligned_enable);
  58 
  59 #endif  /* __lint */
  60 
  61 #if defined(__lint)
  62 
  63 fakeload_pt_setup(uintptr_t ptroot)
  64 {}
  65 
  66 #else /* __lint */
  67 
  68         /*
  69          * We need to set up the world for the first time. We'll do the
  70          * following in order:
  71          *
  72          * o Set the TTBCR to always use TTBR0
  73          * o Set domain 0 to manager mode
  74          * o Program the Page table root
  75          */
  76         ENTRY(fakeload_pt_setup)
  77         mov     r1, #0
  78         mcr     p15, 0, r1, c2, c0, 2
  79         mov     r1, #3
  80         mcr     p15, 0, r1, c3, c0, 0
  81         orr     r0, r0, #0x1b
  82         mcr     p15, 0, r0, c2, c0, 0
  83         bx      lr
  84         SET_SIZE(fakeload_pt_setup)
  85 
  86 #endif /* __lint */
  87 
  88 #if defined(__lint)
  89 
  90 /* ARGSUSED */
  91 void
  92 fakeload_mmu_enable(void)
  93 {}
  94 
  95 #else   /* __lint */
  96 
  97         /*
  98          * We first make sure that the ARMv6 pages are enabled (bit 23) and then
  99          * enable the MMU (bit 0).
 100          */
 101         ENTRY(fakeload_mmu_enable)
 102         mrc     p15, 0, r0, c1, c0, 0
 103         orr     r0, #0x800000
 104         mcr     p15, 0, r0, c1, c0, 0
 105         mrc     p15, 0, r0, c1, c0, 0
 106         orr     r0, #0x1
 107         mcr     p15, 0, r0, c1, c0, 0
 108         bx      lr
 109         SET_SIZE(fakeload_mmu_enable)
 110 #endif  /* __lint */
 111 
 112 
 113         ENTRY(fakeload_exec)
 114         blx     r3
 115         /* We should never execute this. If we do we'll go back to a panic */
 116         bx      lr
 117         SET_SIZE(fakeload_exec)