u-boot/arch/arm/mach-tegra/tegra186/nvtboot_mem.c

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/*
* Copyright (c) 2016, NVIDIA CORPORATION.
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <fdt_support.h>
#include <fdtdec.h>
#include <asm/arch/tegra.h>
DECLARE_GLOBAL_DATA_PTR;
extern unsigned long nvtboot_boot_x0;
/*
* A parsed version of /memory/reg from the DTB that is passed to U-Boot in x0.
*
* We only support up to two banks since that's all the binary bootloader
* ever sets. We assume bank 0 is RAM below 4G and bank 1 is RAM above 4G.
* This is all a fairly safe assumption, since the L4T kernel makes the same
* assumptions, so the bootloader is unlikely to change.
*
* This is written to before relocation, and hence cannot be in .bss, since
* .bss overlaps the DTB that's appended to the U-Boot binary. The initializer
* forces this into .data and avoids this issue. This also has the nice side-
* effect of the content being valid after relocation.
*/
static struct {
u64 start;
u64 size;
} ram_banks[2] = {{1}};
int dram_init(void)
{
unsigned int na, ns;
const void *nvtboot_blob = (void *)nvtboot_boot_x0;
int node, len, i;
const u32 *prop;
memset(ram_banks, 0, sizeof(ram_banks));
na = fdtdec_get_uint(nvtboot_blob, 0, "#address-cells", 2);
ns = fdtdec_get_uint(nvtboot_blob, 0, "#size-cells", 2);
node = fdt_path_offset(nvtboot_blob, "/memory");
if (node < 0) {
error("Can't find /memory node in nvtboot DTB");
hang();
}
prop = fdt_getprop(nvtboot_blob, node, "reg", &len);
if (!prop) {
error("Can't find /memory/reg property in nvtboot DTB");
hang();
}
len /= (na + ns);
if (len > ARRAY_SIZE(ram_banks))
len = ARRAY_SIZE(ram_banks);
gd->ram_size = 0;
for (i = 0; i < len; i++) {
ram_banks[i].start = fdt_read_number(prop, na);
prop += na;
ram_banks[i].size = fdt_read_number(prop, ns);
prop += ns;
gd->ram_size += ram_banks[i].size;
}
return 0;
}
extern unsigned long nvtboot_boot_x0;
int dram_init_banksize(void)
{
int i;
for (i = 0; i < 2; i++) {
gd->bd->bi_dram[i].start = ram_banks[i].start;
gd->bd->bi_dram[i].size = ram_banks[i].size;
}
return 0;
}
ulong board_get_usable_ram_top(ulong total_size)
{
return ram_banks[0].start + ram_banks[0].size;
}