board_init.c 5.1 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. #include <bootstage.h>
  10. DECLARE_GLOBAL_DATA_PTR;
  11. /* Unfortunately x86 or ARM can't compile this code as gd cannot be assigned */
  12. #if !defined(CONFIG_X86) && !defined(CONFIG_ARM)
  13. __weak void arch_setup_gd(struct global_data *gd_ptr)
  14. {
  15. gd = gd_ptr;
  16. }
  17. #endif /* !CONFIG_X86 && !CONFIG_ARM */
  18. /**
  19. * This function is called from board_init_f_init_reserve to set up
  20. * gd->start_addr_sp for stack protection if not already set otherwise
  21. */
  22. __weak void board_init_f_init_stack_protection_addr(ulong base)
  23. {
  24. #if CONFIG_IS_ENABLED(SYS_REPORT_STACK_F_USAGE)
  25. /* set up stack pointer for stack usage if not set yet */
  26. if (!gd->start_addr_sp)
  27. gd->start_addr_sp = base;
  28. #endif
  29. }
  30. /**
  31. * This function is called after the position of the initial stack is
  32. * determined in gd->start_addr_sp. Boards can override it to set up
  33. * stack-checking markers.
  34. */
  35. __weak void board_init_f_init_stack_protection(void)
  36. {
  37. #if CONFIG_IS_ENABLED(SYS_REPORT_STACK_F_USAGE)
  38. ulong stack_bottom = gd->start_addr_sp -
  39. CONFIG_VAL(SIZE_LIMIT_PROVIDE_STACK);
  40. /* substact some safety margin (0x20) since stack is in use here */
  41. memset((void *)stack_bottom, CONFIG_VAL(SYS_STACK_F_CHECK_BYTE),
  42. CONFIG_VAL(SIZE_LIMIT_PROVIDE_STACK) - 0x20);
  43. #endif
  44. }
  45. /*
  46. * Allocate reserved space for use as 'globals' from 'top' address and
  47. * return 'bottom' address of allocated space
  48. *
  49. * Notes:
  50. *
  51. * Actual reservation cannot be done from within this function as
  52. * it requires altering the C stack pointer, so this will be done by
  53. * the caller upon return from this function.
  54. *
  55. * IMPORTANT:
  56. *
  57. * Alignment constraints may differ for each 'chunk' allocated. For now:
  58. *
  59. * - GD is aligned down on a 16-byte boundary
  60. *
  61. * - the early malloc arena is not aligned, therefore it follows the stack
  62. * alignment constraint of the architecture for which we are bulding.
  63. *
  64. * - GD is allocated last, so that the return value of this functions is
  65. * both the bottom of the reserved area and the address of GD, should
  66. * the calling context need it.
  67. */
  68. ulong board_init_f_alloc_reserve(ulong top)
  69. {
  70. /* Reserve early malloc arena */
  71. #if CONFIG_VAL(SYS_MALLOC_F_LEN)
  72. top -= CONFIG_VAL(SYS_MALLOC_F_LEN);
  73. #endif
  74. /* LAST : reserve GD (rounded up to a multiple of 16 bytes) */
  75. top = rounddown(top-sizeof(struct global_data), 16);
  76. return top;
  77. }
  78. /*
  79. * Initialize reserved space (which has been safely allocated on the C
  80. * stack from the C runtime environment handling code).
  81. *
  82. * Notes:
  83. *
  84. * Actual reservation was done by the caller; the locations from base
  85. * to base+size-1 (where 'size' is the value returned by the allocation
  86. * function above) can be accessed freely without risk of corrupting the
  87. * C runtime environment.
  88. *
  89. * IMPORTANT:
  90. *
  91. * Upon return from the allocation function above, on some architectures
  92. * the caller will set gd to the lowest reserved location. Therefore, in
  93. * this initialization function, the global data MUST be placed at base.
  94. *
  95. * ALSO IMPORTANT:
  96. *
  97. * On some architectures, gd will already be good when entering this
  98. * function. On others, it will only be good once arch_setup_gd() returns.
  99. * Therefore, global data accesses must be done:
  100. *
  101. * - through gd_ptr if before the call to arch_setup_gd();
  102. *
  103. * - through gd once arch_setup_gd() has been called.
  104. *
  105. * Do not use 'gd->' until arch_setup_gd() has been called!
  106. *
  107. * IMPORTANT TOO:
  108. *
  109. * Initialization for each "chunk" (GD, early malloc arena...) ends with
  110. * an incrementation line of the form 'base += <some size>'. The last of
  111. * these incrementations seems useless, as base will not be used any
  112. * more after this incrementation; but if/when a new "chunk" is appended,
  113. * this increment will be essential as it will give base right value for
  114. * this new chunk (which will have to end with its own incrementation
  115. * statement). Besides, the compiler's optimizer will silently detect
  116. * and remove the last base incrementation, therefore leaving that last
  117. * (seemingly useless) incrementation causes no code increase.
  118. */
  119. void board_init_f_init_reserve(ulong base)
  120. {
  121. struct global_data *gd_ptr;
  122. /*
  123. * clear GD entirely and set it up.
  124. * Use gd_ptr, as gd may not be properly set yet.
  125. */
  126. gd_ptr = (struct global_data *)base;
  127. /* zero the area */
  128. memset(gd_ptr, '\0', sizeof(*gd));
  129. /* set GD unless architecture did it already */
  130. #if !defined(CONFIG_ARM)
  131. arch_setup_gd(gd_ptr);
  132. #endif
  133. if (CONFIG_IS_ENABLED(SYS_REPORT_STACK_F_USAGE))
  134. board_init_f_init_stack_protection_addr(base);
  135. /* next alloc will be higher by one GD plus 16-byte alignment */
  136. base += roundup(sizeof(struct global_data), 16);
  137. /*
  138. * record early malloc arena start.
  139. * Use gd as it is now properly set for all architectures.
  140. */
  141. #if CONFIG_VAL(SYS_MALLOC_F_LEN)
  142. /* go down one 'early malloc arena' */
  143. gd->malloc_base = base;
  144. #endif
  145. if (CONFIG_IS_ENABLED(SYS_REPORT_STACK_F_USAGE))
  146. board_init_f_init_stack_protection();
  147. }
  148. /*
  149. * Board-specific Platform code can reimplement show_boot_progress () if needed
  150. */
  151. __weak void show_boot_progress(int val) {}