1 /* 2 * Copyright (c) 2016, NVIDIA CORPORATION. 3 * 4 * SPDX-License-Identifier: GPL-2.0+ 5 */ 6 7 #include <common.h> 8 #include <fdt_support.h> 9 #include <fdtdec.h> 10 #include <asm/arch/tegra.h> 11 12 DECLARE_GLOBAL_DATA_PTR; 13 14 extern unsigned long nvtboot_boot_x0; 15 16 /* 17 * A parsed version of /memory/reg from the DTB that is passed to U-Boot in x0. 18 * 19 * We only support up to two banks since that's all the binary bootloader 20 * ever sets. We assume bank 0 is RAM below 4G and bank 1 is RAM above 4G. 21 * This is all a fairly safe assumption, since the L4T kernel makes the same 22 * assumptions, so the bootloader is unlikely to change. 23 * 24 * This is written to before relocation, and hence cannot be in .bss, since 25 * .bss overlaps the DTB that's appended to the U-Boot binary. The initializer 26 * forces this into .data and avoids this issue. This also has the nice side- 27 * effect of the content being valid after relocation. 28 */ 29 static struct { 30 u64 start; 31 u64 size; 32 } ram_banks[2] = {{1}}; 33 34 int dram_init(void) 35 { 36 unsigned int na, ns; 37 const void *nvtboot_blob = (void *)nvtboot_boot_x0; 38 int node, len, i; 39 const u32 *prop; 40 41 memset(ram_banks, 0, sizeof(ram_banks)); 42 43 na = fdtdec_get_uint(nvtboot_blob, 0, "#address-cells", 2); 44 ns = fdtdec_get_uint(nvtboot_blob, 0, "#size-cells", 2); 45 46 node = fdt_path_offset(nvtboot_blob, "/memory"); 47 if (node < 0) { 48 error("Can't find /memory node in nvtboot DTB"); 49 hang(); 50 } 51 prop = fdt_getprop(nvtboot_blob, node, "reg", &len); 52 if (!prop) { 53 error("Can't find /memory/reg property in nvtboot DTB"); 54 hang(); 55 } 56 57 len /= (na + ns); 58 if (len > ARRAY_SIZE(ram_banks)) 59 len = ARRAY_SIZE(ram_banks); 60 61 gd->ram_size = 0; 62 for (i = 0; i < len; i++) { 63 ram_banks[i].start = of_read_number(prop, na); 64 prop += na; 65 ram_banks[i].size = of_read_number(prop, ns); 66 prop += ns; 67 gd->ram_size += ram_banks[i].size; 68 } 69 70 return 0; 71 } 72 73 extern unsigned long nvtboot_boot_x0; 74 75 void dram_init_banksize(void) 76 { 77 int i; 78 79 for (i = 0; i < 2; i++) { 80 gd->bd->bi_dram[i].start = ram_banks[i].start; 81 gd->bd->bi_dram[i].size = ram_banks[i].size; 82 } 83 } 84 85 ulong board_get_usable_ram_top(ulong total_size) 86 { 87 return ram_banks[0].start + ram_banks[0].size; 88 } 89