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