1 files changed, 88 insertions, 0 deletions
diff --git a/arch/arm/mach-tegra/tegra186/nvtboot_mem.c b/arch/arm/mach-tegra/tegra186/nvtboot_mem.c
new file mode 100644
index 0000000000..37dd8d4334
--- /dev/null
+++ b/arch/arm/mach-tegra/tegra186/nvtboot_mem.c
@@ -0,0 +1,88 @@
+/*
+ * 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 = of_read_number(prop, na);
+		prop += na;
+		ram_banks[i].size = of_read_number(prop, ns);
+		prop += ns;
+		gd->ram_size += ram_banks[i].size;
+	}
+
+	return 0;
+}
+
+extern unsigned long nvtboot_boot_x0;
+
+void 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;
+	}
+}
+
+ulong board_get_usable_ram_top(ulong total_size)
+{
+	return ram_banks[0].start + ram_banks[0].size;
+}