From 2a5f7f20747637cd1f94d4accfd7caa99a7c6035 Mon Sep 17 00:00:00 2001 From: Stephen Warren Date: Mon, 18 Jul 2016 17:01:51 -0600 Subject: [PATCH] ARM: tegra: pick up actual memory size On Tegra186, U-Boot is booted by the binary firmware as if it were a Linux kernel. Consequently, a DTB is passed to U-Boot. Cache the address of that DTB, and parse the /memory/reg property to determine the actual RAM regions that U-Boot and subsequent EL2/EL1 SW may actually use. Given the binary FW passes a DTB to U-Boot, I anticipate the suggestion that U-Boot use that DTB as its control DTB. I don't believe that would work well, so I do not plan to put any effort into this. By default the FW-supplied DTB is the L4T kernel's DTB, which uses non-upstreamed DT bindings. U-Boot aims to use only upstreamed DT bindings, or as close as it can get. Replacing this DTB with a DTB using upstream bindings is physically quite easy; simply replace the content of one of the GPT partitions on the eMMC. However, the binary FW at least partially relies on the existence/content of some nodes in the DTB, and that requires the DTB to be written according to downstream bindings. Equally, if U-Boot continues to use appended DTBs built from its own source tree, as it does for all other Tegra platforms, development and deployment is much easier. Signed-off-by: Stephen Warren Signed-off-by: Tom Warren --- arch/arm/mach-tegra/board186.c | 12 ---- arch/arm/mach-tegra/tegra186/Makefile | 2 + arch/arm/mach-tegra/tegra186/nvtboot_ll.S | 20 +++++++ arch/arm/mach-tegra/tegra186/nvtboot_mem.c | 88 ++++++++++++++++++++++++++++++ 4 files changed, 110 insertions(+), 12 deletions(-) create mode 100644 arch/arm/mach-tegra/tegra186/nvtboot_ll.S create mode 100644 arch/arm/mach-tegra/tegra186/nvtboot_mem.c diff --git a/arch/arm/mach-tegra/board186.c b/arch/arm/mach-tegra/board186.c index f4b6152..876ccba 100644 --- a/arch/arm/mach-tegra/board186.c +++ b/arch/arm/mach-tegra/board186.c @@ -11,12 +11,6 @@ DECLARE_GLOBAL_DATA_PTR; -int dram_init(void) -{ - gd->ram_size = (1.5 * 1024 * 1024 * 1024); - return 0; -} - int board_early_init_f(void) { return 0; @@ -32,12 +26,6 @@ int board_late_init(void) return 0; } -void dram_init_banksize(void) -{ - gd->bd->bi_dram[0].start = CONFIG_SYS_SDRAM_BASE; - gd->bd->bi_dram[0].size = gd->ram_size; -} - void pad_init_mmc(struct mmc_host *host) { } diff --git a/arch/arm/mach-tegra/tegra186/Makefile b/arch/arm/mach-tegra/tegra186/Makefile index 188b097..033d600 100644 --- a/arch/arm/mach-tegra/tegra186/Makefile +++ b/arch/arm/mach-tegra/tegra186/Makefile @@ -3,3 +3,5 @@ # SPDX-License-Identifier: GPL-2.0 obj-y += ../board186.o +obj-y += nvtboot_ll.o +obj-y += nvtboot_mem.o diff --git a/arch/arm/mach-tegra/tegra186/nvtboot_ll.S b/arch/arm/mach-tegra/tegra186/nvtboot_ll.S new file mode 100644 index 0000000..1eab890 --- /dev/null +++ b/arch/arm/mach-tegra/tegra186/nvtboot_ll.S @@ -0,0 +1,20 @@ +/* + * Save nvtboot-related boot-time CPU state + * + * (C) Copyright 2015-2016 NVIDIA Corporation + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include +#include + +.globl nvtboot_boot_x0 +nvtboot_boot_x0: + .dword 0 + +ENTRY(save_boot_params) + adr x8, nvtboot_boot_x0 + str x0, [x8] + b save_boot_params_ret +ENDPROC(save_boot_params) 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 0000000..37dd8d4 --- /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 +#include +#include +#include + +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; +}