1 /* 2 * Code shared between SPL and U-Boot proper 3 * 4 * Copyright (c) 2015 Google, Inc 5 * Written by Simon Glass <sjg@chromium.org> 6 * 7 * SPDX-License-Identifier: GPL-2.0+ 8 */ 9 10 #include <common.h> 11 12 DECLARE_GLOBAL_DATA_PTR; 13 14 /* Unfortunately x86 or ARM can't compile this code as gd cannot be assigned */ 15 #if !defined(CONFIG_X86) && !defined(CONFIG_ARM) 16 __weak void arch_setup_gd(struct global_data *gd_ptr) 17 { 18 gd = gd_ptr; 19 } 20 #endif /* !CONFIG_X86 && !CONFIG_ARM */ 21 22 /* 23 * Allocate reserved space for use as 'globals' from 'top' address and 24 * return 'bottom' address of allocated space 25 * 26 * Notes: 27 * 28 * Actual reservation cannot be done from within this function as 29 * it requires altering the C stack pointer, so this will be done by 30 * the caller upon return from this function. 31 * 32 * IMPORTANT: 33 * 34 * Alignment constraints may differ for each 'chunk' allocated. For now: 35 * 36 * - GD is aligned down on a 16-byte boundary 37 * 38 * - the early malloc arena is not aligned, therefore it follows the stack 39 * alignment constraint of the architecture for which we are bulding. 40 * 41 * - GD is allocated last, so that the return value of this functions is 42 * both the bottom of the reserved area and the address of GD, should 43 * the calling context need it. 44 */ 45 46 ulong board_init_f_alloc_reserve(ulong top) 47 { 48 /* Reserve early malloc arena */ 49 #if defined(CONFIG_SYS_MALLOC_F) 50 top -= CONFIG_SYS_MALLOC_F_LEN; 51 #endif 52 /* LAST : reserve GD (rounded up to a multiple of 16 bytes) */ 53 top = rounddown(top-sizeof(struct global_data), 16); 54 55 return top; 56 } 57 58 /* 59 * Initialize reserved space (which has been safely allocated on the C 60 * stack from the C runtime environment handling code). 61 * 62 * Notes: 63 * 64 * Actual reservation was done by the caller; the locations from base 65 * to base+size-1 (where 'size' is the value returned by the allocation 66 * function above) can be accessed freely without risk of corrupting the 67 * C runtime environment. 68 * 69 * IMPORTANT: 70 * 71 * Upon return from the allocation function above, on some architectures 72 * the caller will set gd to the lowest reserved location. Therefore, in 73 * this initialization function, the global data MUST be placed at base. 74 * 75 * ALSO IMPORTANT: 76 * 77 * On some architectures, gd will already be good when entering this 78 * function. On others, it will only be good once arch_setup_gd() returns. 79 * Therefore, global data accesses must be done: 80 * 81 * - through gd_ptr if before the call to arch_setup_gd(); 82 * 83 * - through gd once arch_setup_gd() has been called. 84 * 85 * Do not use 'gd->' until arch_setup_gd() has been called! 86 * 87 * IMPORTANT TOO: 88 * 89 * Initialization for each "chunk" (GD, early malloc arena...) ends with 90 * an incrementation line of the form 'base += <some size>'. The last of 91 * these incrementations seems useless, as base will not be used any 92 * more after this incrementation; but if/when a new "chunk" is appended, 93 * this increment will be essential as it will give base right value for 94 * this new chunk (which will have to end with its own incrementation 95 * statement). Besides, the compiler's optimizer will silently detect 96 * and remove the last base incrementation, therefore leaving that last 97 * (seemingly useless) incrementation causes no code increase. 98 */ 99 100 void board_init_f_init_reserve(ulong base) 101 { 102 struct global_data *gd_ptr; 103 104 /* 105 * clear GD entirely and set it up. 106 * Use gd_ptr, as gd may not be properly set yet. 107 */ 108 109 gd_ptr = (struct global_data *)base; 110 /* zero the area */ 111 memset(gd_ptr, '\0', sizeof(*gd)); 112 /* set GD unless architecture did it already */ 113 #if !defined(CONFIG_ARM) 114 arch_setup_gd(gd_ptr); 115 #endif 116 /* next alloc will be higher by one GD plus 16-byte alignment */ 117 base += roundup(sizeof(struct global_data), 16); 118 119 /* 120 * record early malloc arena start. 121 * Use gd as it is now properly set for all architectures. 122 */ 123 124 #if defined(CONFIG_SYS_MALLOC_F) 125 /* go down one 'early malloc arena' */ 126 gd->malloc_base = base; 127 /* next alloc will be higher by one 'early malloc arena' size */ 128 base += CONFIG_SYS_MALLOC_F_LEN; 129 #endif 130 } 131 132 /* 133 * Board-specific Platform code can reimplement show_boot_progress () if needed 134 */ 135 __weak void show_boot_progress(int val) {} 136