LXR uboot/common/init/board

   1/*
   2 * Code shared between SPL and U-Boot proper
   3 *
   4 * Copyright (c) 2015 Google, Inc
   5 * Written by Simon Glass <sjg@chromium.org>
   6 *
   7 * SPDX-License-Identifier:     GPL-2.0+
   8 */
   9
  10#include <common.h>
  11
  12DECLARE_GLOBAL_DATA_PTR;
  13
  14/*
  15 * It isn't trivial to figure out whether memcpy() exists. The arch-specific
  16 * memcpy() is not normally available in SPL due to code size.
  17 */
  18#if !defined(CONFIG_SPL_BUILD) || \
  19                (defined(CONFIG_SPL_LIBGENERIC_SUPPORT) && \
  20                !defined(CONFIG_USE_ARCH_MEMSET))
  21#define _USE_MEMCPY
  22#endif
  23
  24/* Unfortunately x86 or ARM can't compile this code as gd cannot be assigned */
  25#if !defined(CONFIG_X86) && !defined(CONFIG_ARM)
  26__weak void arch_setup_gd(struct global_data *gd_ptr)
  27{
  28        gd = gd_ptr;
  29}
  30#endif /* !CONFIG_X86 && !CONFIG_ARM */
  31
  32/*
  33 * Allocate reserved space for use as 'globals' from 'top' address and
  34 * return 'bottom' address of allocated space
  35 *
  36 * Notes:
  37 *
  38 * Actual reservation cannot be done from within this function as
  39 * it requires altering the C stack pointer, so this will be done by
  40 * the caller upon return from this function.
  41 *
  42 * IMPORTANT:
  43 *
  44 * Alignment constraints may differ for each 'chunk' allocated. For now:
  45 *
  46 * - GD is aligned down on a 16-byte boundary
  47 *
  48 *  - the early malloc arena is not aligned, therefore it follows the stack
  49 *   alignment constraint of the architecture for which we are bulding.
  50 *
  51 *  - GD is allocated last, so that the return value of this functions is
  52 *   both the bottom of the reserved area and the address of GD, should
  53 *   the calling context need it.
  54 */
  55
  56ulong board_init_f_alloc_reserve(ulong top)
  57{
  58        /* Reserve early malloc arena */
  59#if defined(CONFIG_SYS_MALLOC_F)
  60        top -= CONFIG_SYS_MALLOC_F_LEN;
  61#endif
  62        /* LAST : reserve GD (rounded up to a multiple of 16 bytes) */
  63        top = rounddown(top-sizeof(struct global_data), 16);
  64
  65        return top;
  66}
  67
  68/*
  69 * Initialize reserved space (which has been safely allocated on the C
  70 * stack from the C runtime environment handling code).
  71 *
  72 * Notes:
  73 *
  74 * Actual reservation was done by the caller; the locations from base
  75 * to base+size-1 (where 'size' is the value returned by the allocation
  76 * function above) can be accessed freely without risk of corrupting the
  77 * C runtime environment.
  78 *
  79 * IMPORTANT:
  80 *
  81 * Upon return from the allocation function above, on some architectures
  82 * the caller will set gd to the lowest reserved location. Therefore, in
  83 * this initialization function, the global data MUST be placed at base.
  84 *
  85 * ALSO IMPORTANT:
  86 *
  87 * On some architectures, gd will already be good when entering this
  88 * function. On others, it will only be good once arch_setup_gd() returns.
  89 * Therefore, global data accesses must be done:
  90 *
  91 * - through gd_ptr if before the call to arch_setup_gd();
  92 *
  93 * - through gd once arch_setup_gd() has been called.
  94 *
  95 * Do not use 'gd->' until arch_setup_gd() has been called!
  96 *
  97 * IMPORTANT TOO:
  98 *
  99 * Initialization for each "chunk" (GD, early malloc arena...) ends with
 100 * an incrementation line of the form 'base += <some size>'. The last of
 101 * these incrementations seems useless, as base will not be used any
 102 * more after this incrementation; but if/when a new "chunk" is appended,
 103 * this increment will be essential as it will give base right value for
 104 * this new chunk (which will have to end with its own incrementation
 105 * statement). Besides, the compiler's optimizer will silently detect
 106 * and remove the last base incrementation, therefore leaving that last
 107 * (seemingly useless) incrementation causes no code increase.
 108 */
 109
 110void board_init_f_init_reserve(ulong base)
 111{
 112        struct global_data *gd_ptr;
 113#ifndef _USE_MEMCPY
 114        int *ptr;
 115#endif
 116
 117        /*
 118         * clear GD entirely and set it up.
 119         * Use gd_ptr, as gd may not be properly set yet.
 120         */
 121
 122        gd_ptr = (struct global_data *)base;
 123        /* zero the area */
 124#ifdef _USE_MEMCPY
 125        memset(gd_ptr, '\0', sizeof(*gd));
 126#else
 127        for (ptr = (int *)gd_ptr; ptr < (int *)(gd_ptr + 1); )
 128                *ptr++ = 0;
 129#endif
 130        /* set GD unless architecture did it already */
 131#if !defined(CONFIG_ARM)
 132        arch_setup_gd(gd_ptr);
 133#endif
 134        /* next alloc will be higher by one GD plus 16-byte alignment */
 135        base += roundup(sizeof(struct global_data), 16);
 136
 137        /*
 138         * record early malloc arena start.
 139         * Use gd as it is now properly set for all architectures.
 140         */
 141
 142#if defined(CONFIG_SYS_MALLOC_F)
 143        /* go down one 'early malloc arena' */
 144        gd->malloc_base = base;
 145        /* next alloc will be higher by one 'early malloc arena' size */
 146        base += CONFIG_SYS_MALLOC_F_LEN;
 147#endif
 148}
 149
 150/*
 151 * Board-specific Platform code can reimplement show_boot_progress () if needed
 152 */
 153__weak void show_boot_progress(int val) {}
 154