board_init.c 4.7 KB

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  1. // SPDX-License-Identifier: GPL-2.0+
  2. /*
  3. * Code shared between SPL and U-Boot proper
  4. *
  5. * Copyright (c) 2015 Google, Inc
  6. * Written by Simon Glass <sjg@chromium.org>
  7. */
  8. #include <common.h>
  9. DECLARE_GLOBAL_DATA_PTR;
  10. /* Unfortunately x86 or ARM can't compile this code as gd cannot be assigned */
  11. #if !defined(CONFIG_X86) && !defined(CONFIG_ARM)
  12. __weak void arch_setup_gd(struct global_data *gd_ptr)
  13. {
  14. gd = gd_ptr;
  15. }
  16. #endif /* !CONFIG_X86 && !CONFIG_ARM */
  17. /**
  18. * This function is called after the position of the initial stack is
  19. * determined in gd->start_addr_sp. Boards can override it to set up
  20. * stack-checking markers.
  21. */
  22. __weak void board_init_f_init_stack_protection(void)
  23. {
  24. #if CONFIG_IS_ENABLED(SYS_REPORT_STACK_F_USAGE)
  25. ulong stack_bottom = gd->start_addr_sp -
  26. CONFIG_VAL(SIZE_LIMIT_PROVIDE_STACK);
  27. /* substact some safety margin (0x20) since stack is in use here */
  28. memset((void *)stack_bottom, CONFIG_VAL(SYS_STACK_F_CHECK_BYTE),
  29. CONFIG_VAL(SIZE_LIMIT_PROVIDE_STACK) - 0x20);
  30. #endif
  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. ulong board_init_f_alloc_reserve(ulong top)
  56. {
  57. /* Reserve early malloc arena */
  58. #if CONFIG_VAL(SYS_MALLOC_F_LEN)
  59. top -= CONFIG_VAL(SYS_MALLOC_F_LEN);
  60. #endif
  61. /* LAST : reserve GD (rounded up to a multiple of 16 bytes) */
  62. top = rounddown(top-sizeof(struct global_data), 16);
  63. return top;
  64. }
  65. /*
  66. * Initialize reserved space (which has been safely allocated on the C
  67. * stack from the C runtime environment handling code).
  68. *
  69. * Notes:
  70. *
  71. * Actual reservation was done by the caller; the locations from base
  72. * to base+size-1 (where 'size' is the value returned by the allocation
  73. * function above) can be accessed freely without risk of corrupting the
  74. * C runtime environment.
  75. *
  76. * IMPORTANT:
  77. *
  78. * Upon return from the allocation function above, on some architectures
  79. * the caller will set gd to the lowest reserved location. Therefore, in
  80. * this initialization function, the global data MUST be placed at base.
  81. *
  82. * ALSO IMPORTANT:
  83. *
  84. * On some architectures, gd will already be good when entering this
  85. * function. On others, it will only be good once arch_setup_gd() returns.
  86. * Therefore, global data accesses must be done:
  87. *
  88. * - through gd_ptr if before the call to arch_setup_gd();
  89. *
  90. * - through gd once arch_setup_gd() has been called.
  91. *
  92. * Do not use 'gd->' until arch_setup_gd() has been called!
  93. *
  94. * IMPORTANT TOO:
  95. *
  96. * Initialization for each "chunk" (GD, early malloc arena...) ends with
  97. * an incrementation line of the form 'base += <some size>'. The last of
  98. * these incrementations seems useless, as base will not be used any
  99. * more after this incrementation; but if/when a new "chunk" is appended,
  100. * this increment will be essential as it will give base right value for
  101. * this new chunk (which will have to end with its own incrementation
  102. * statement). Besides, the compiler's optimizer will silently detect
  103. * and remove the last base incrementation, therefore leaving that last
  104. * (seemingly useless) incrementation causes no code increase.
  105. */
  106. void board_init_f_init_reserve(ulong base)
  107. {
  108. struct global_data *gd_ptr;
  109. /*
  110. * clear GD entirely and set it up.
  111. * Use gd_ptr, as gd may not be properly set yet.
  112. */
  113. gd_ptr = (struct global_data *)base;
  114. /* zero the area */
  115. memset(gd_ptr, '\0', sizeof(*gd));
  116. /* set GD unless architecture did it already */
  117. #if !defined(CONFIG_ARM)
  118. arch_setup_gd(gd_ptr);
  119. #endif
  120. /* next alloc will be higher by one GD plus 16-byte alignment */
  121. base += roundup(sizeof(struct global_data), 16);
  122. /*
  123. * record early malloc arena start.
  124. * Use gd as it is now properly set for all architectures.
  125. */
  126. #if CONFIG_VAL(SYS_MALLOC_F_LEN)
  127. /* go down one 'early malloc arena' */
  128. gd->malloc_base = base;
  129. /* next alloc will be higher by one 'early malloc arena' size */
  130. base += CONFIG_VAL(SYS_MALLOC_F_LEN);
  131. #endif
  132. if (CONFIG_IS_ENABLED(SYS_REPORT_STACK_F_USAGE))
  133. board_init_f_init_stack_protection();
  134. }
  135. /*
  136. * Board-specific Platform code can reimplement show_boot_progress () if needed
  137. */
  138. __weak void show_boot_progress(int val) {}