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) 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 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 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 */ 134 __weak void show_boot_progress(int val) {} 135