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
9 #include <common.h>
10
11 DECLARE_GLOBAL_DATA_PTR;
12
13 /* Unfortunately x86 or ARM can't compile this code as gd cannot be assigned */
14 #if !defined(CONFIG_X86) && !defined(CONFIG_ARM)
arch_setup_gd(struct global_data * gd_ptr)15 __weak void arch_setup_gd(struct global_data *gd_ptr)
16 {
17 gd = gd_ptr;
18 }
19 #endif /* !CONFIG_X86 && !CONFIG_ARM */
20
21 /**
22 * This function is called after the position of the initial stack is
23 * determined in gd->start_addr_sp. Boards can override it to set up
24 * stack-checking markers.
25 */
board_init_f_init_stack_protection(void)26 __weak void board_init_f_init_stack_protection(void)
27 {
28 #if CONFIG_IS_ENABLED(SYS_REPORT_STACK_F_USAGE)
29 ulong stack_bottom = gd->start_addr_sp -
30 CONFIG_VAL(SIZE_LIMIT_PROVIDE_STACK);
31
32 /* substact some safety margin (0x20) since stack is in use here */
33 memset((void *)stack_bottom, CONFIG_VAL(SYS_STACK_F_CHECK_BYTE),
34 CONFIG_VAL(SIZE_LIMIT_PROVIDE_STACK) - 0x20);
35 #endif
36 }
37
38 /*
39 * Allocate reserved space for use as 'globals' from 'top' address and
40 * return 'bottom' address of allocated space
41 *
42 * Notes:
43 *
44 * Actual reservation cannot be done from within this function as
45 * it requires altering the C stack pointer, so this will be done by
46 * the caller upon return from this function.
47 *
48 * IMPORTANT:
49 *
50 * Alignment constraints may differ for each 'chunk' allocated. For now:
51 *
52 * - GD is aligned down on a 16-byte boundary
53 *
54 * - the early malloc arena is not aligned, therefore it follows the stack
55 * alignment constraint of the architecture for which we are bulding.
56 *
57 * - GD is allocated last, so that the return value of this functions is
58 * both the bottom of the reserved area and the address of GD, should
59 * the calling context need it.
60 */
61
board_init_f_alloc_reserve(ulong top)62 ulong board_init_f_alloc_reserve(ulong top)
63 {
64 /* Reserve early malloc arena */
65 #if CONFIG_VAL(SYS_MALLOC_F_LEN)
66 top -= CONFIG_VAL(SYS_MALLOC_F_LEN);
67 #endif
68 /* LAST : reserve GD (rounded up to a multiple of 16 bytes) */
69 top = rounddown(top-sizeof(struct global_data), 16);
70
71 return top;
72 }
73
74 /*
75 * Initialize reserved space (which has been safely allocated on the C
76 * stack from the C runtime environment handling code).
77 *
78 * Notes:
79 *
80 * Actual reservation was done by the caller; the locations from base
81 * to base+size-1 (where 'size' is the value returned by the allocation
82 * function above) can be accessed freely without risk of corrupting the
83 * C runtime environment.
84 *
85 * IMPORTANT:
86 *
87 * Upon return from the allocation function above, on some architectures
88 * the caller will set gd to the lowest reserved location. Therefore, in
89 * this initialization function, the global data MUST be placed at base.
90 *
91 * ALSO IMPORTANT:
92 *
93 * On some architectures, gd will already be good when entering this
94 * function. On others, it will only be good once arch_setup_gd() returns.
95 * Therefore, global data accesses must be done:
96 *
97 * - through gd_ptr if before the call to arch_setup_gd();
98 *
99 * - through gd once arch_setup_gd() has been called.
100 *
101 * Do not use 'gd->' until arch_setup_gd() has been called!
102 *
103 * IMPORTANT TOO:
104 *
105 * Initialization for each "chunk" (GD, early malloc arena...) ends with
106 * an incrementation line of the form 'base += <some size>'. The last of
107 * these incrementations seems useless, as base will not be used any
108 * more after this incrementation; but if/when a new "chunk" is appended,
109 * this increment will be essential as it will give base right value for
110 * this new chunk (which will have to end with its own incrementation
111 * statement). Besides, the compiler's optimizer will silently detect
112 * and remove the last base incrementation, therefore leaving that last
113 * (seemingly useless) incrementation causes no code increase.
114 */
115
board_init_f_init_reserve(ulong base)116 void board_init_f_init_reserve(ulong base)
117 {
118 struct global_data *gd_ptr;
119
120 /*
121 * clear GD entirely and set it up.
122 * Use gd_ptr, as gd may not be properly set yet.
123 */
124
125 gd_ptr = (struct global_data *)base;
126 /* zero the area */
127 memset(gd_ptr, '\0', sizeof(*gd));
128 /* set GD unless architecture did it already */
129 #if !defined(CONFIG_ARM)
130 arch_setup_gd(gd_ptr);
131 #endif
132 /* next alloc will be higher by one GD plus 16-byte alignment */
133 base += roundup(sizeof(struct global_data), 16);
134
135 /*
136 * record early malloc arena start.
137 * Use gd as it is now properly set for all architectures.
138 */
139
140 #if CONFIG_VAL(SYS_MALLOC_F_LEN)
141 /* go down one 'early malloc arena' */
142 gd->malloc_base = base;
143 /* next alloc will be higher by one 'early malloc arena' size */
144 base += CONFIG_VAL(SYS_MALLOC_F_LEN);
145 #endif
146
147 if (CONFIG_IS_ENABLED(SYS_REPORT_STACK_F_USAGE))
148 board_init_f_init_stack_protection();
149 }
150
151 /*
152 * Board-specific Platform code can reimplement show_boot_progress () if needed
153 */
show_boot_progress(int val)154 __weak void show_boot_progress(int val) {}
155