1 // SPDX-License-Identifier: GPL-2.0+
3 * Code shared between SPL and U-Boot proper
5 * Copyright (c) 2015 Google, Inc
6 * Written by Simon Glass <sjg@chromium.org>
11 DECLARE_GLOBAL_DATA_PTR;
13 /* Unfortunately x86 or ARM can't compile this code as gd cannot be assigned */
14 #if !defined(CONFIG_X86) && !defined(CONFIG_ARM)
15 __weak void arch_setup_gd(struct global_data *gd_ptr)
19 #endif /* !CONFIG_X86 && !CONFIG_ARM */
22 * This function is called from board_init_f_init_reserve to set up
23 * gd->start_addr_sp for stack protection if not already set otherwise
25 __weak void board_init_f_init_stack_protection_addr(ulong base)
27 #if CONFIG_IS_ENABLED(SYS_REPORT_STACK_F_USAGE)
28 /* set up stack pointer for stack usage if not set yet */
29 if (!gd->start_addr_sp)
30 gd->start_addr_sp = base;
35 * This function is called after the position of the initial stack is
36 * determined in gd->start_addr_sp. Boards can override it to set up
37 * stack-checking markers.
39 __weak void board_init_f_init_stack_protection(void)
41 #if CONFIG_IS_ENABLED(SYS_REPORT_STACK_F_USAGE)
42 ulong stack_bottom = gd->start_addr_sp -
43 CONFIG_VAL(SIZE_LIMIT_PROVIDE_STACK);
45 /* substact some safety margin (0x20) since stack is in use here */
46 memset((void *)stack_bottom, CONFIG_VAL(SYS_STACK_F_CHECK_BYTE),
47 CONFIG_VAL(SIZE_LIMIT_PROVIDE_STACK) - 0x20);
52 * Allocate reserved space for use as 'globals' from 'top' address and
53 * return 'bottom' address of allocated space
57 * Actual reservation cannot be done from within this function as
58 * it requires altering the C stack pointer, so this will be done by
59 * the caller upon return from this function.
63 * Alignment constraints may differ for each 'chunk' allocated. For now:
65 * - GD is aligned down on a 16-byte boundary
67 * - the early malloc arena is not aligned, therefore it follows the stack
68 * alignment constraint of the architecture for which we are bulding.
70 * - GD is allocated last, so that the return value of this functions is
71 * both the bottom of the reserved area and the address of GD, should
72 * the calling context need it.
75 ulong board_init_f_alloc_reserve(ulong top)
77 /* Reserve early malloc arena */
78 #if CONFIG_VAL(SYS_MALLOC_F_LEN)
79 top -= CONFIG_VAL(SYS_MALLOC_F_LEN);
81 /* LAST : reserve GD (rounded up to a multiple of 16 bytes) */
82 top = rounddown(top-sizeof(struct global_data), 16);
88 * Initialize reserved space (which has been safely allocated on the C
89 * stack from the C runtime environment handling code).
93 * Actual reservation was done by the caller; the locations from base
94 * to base+size-1 (where 'size' is the value returned by the allocation
95 * function above) can be accessed freely without risk of corrupting the
96 * C runtime environment.
100 * Upon return from the allocation function above, on some architectures
101 * the caller will set gd to the lowest reserved location. Therefore, in
102 * this initialization function, the global data MUST be placed at base.
106 * On some architectures, gd will already be good when entering this
107 * function. On others, it will only be good once arch_setup_gd() returns.
108 * Therefore, global data accesses must be done:
110 * - through gd_ptr if before the call to arch_setup_gd();
112 * - through gd once arch_setup_gd() has been called.
114 * Do not use 'gd->' until arch_setup_gd() has been called!
118 * Initialization for each "chunk" (GD, early malloc arena...) ends with
119 * an incrementation line of the form 'base += <some size>'. The last of
120 * these incrementations seems useless, as base will not be used any
121 * more after this incrementation; but if/when a new "chunk" is appended,
122 * this increment will be essential as it will give base right value for
123 * this new chunk (which will have to end with its own incrementation
124 * statement). Besides, the compiler's optimizer will silently detect
125 * and remove the last base incrementation, therefore leaving that last
126 * (seemingly useless) incrementation causes no code increase.
129 void board_init_f_init_reserve(ulong base)
131 struct global_data *gd_ptr;
134 * clear GD entirely and set it up.
135 * Use gd_ptr, as gd may not be properly set yet.
138 gd_ptr = (struct global_data *)base;
140 memset(gd_ptr, '\0', sizeof(*gd));
141 /* set GD unless architecture did it already */
142 #if !defined(CONFIG_ARM)
143 arch_setup_gd(gd_ptr);
146 if (CONFIG_IS_ENABLED(SYS_REPORT_STACK_F_USAGE))
147 board_init_f_init_stack_protection_addr(base);
149 /* next alloc will be higher by one GD plus 16-byte alignment */
150 base += roundup(sizeof(struct global_data), 16);
153 * record early malloc arena start.
154 * Use gd as it is now properly set for all architectures.
157 #if CONFIG_VAL(SYS_MALLOC_F_LEN)
158 /* go down one 'early malloc arena' */
159 gd->malloc_base = base;
162 if (CONFIG_IS_ENABLED(SYS_REPORT_STACK_F_USAGE))
163 board_init_f_init_stack_protection();
167 * Board-specific Platform code can reimplement show_boot_progress () if needed
169 __weak void show_boot_progress(int val) {}