Hi Rob,
On Thursday 24 January 2013 04:20 PM, Vineet Gupta wrote:
> This is minimal infrastructure needed for devicetree work.
> It uses an a sample "skeleton" devicetree - embedded in kernel image -
> to print the board, manufacturer by parsing the top-level "compatible"
> string.
>
> As of now we don't need any additional "board" specific "machine_desc".
>
> TODO: support interpreting the command line as boot-loader passed dtb
>
> Signed-off-by: Vineet Gupta <vgupta-HKixBCOQz3hWk0Htik3J/w@xxxxxxxxxxxxxxxx>
> Cc: Arnd Bergmann <arnd-r2nGTMty4D4@xxxxxxxxxxxxxxxx>
> Cc: Grant Likely <grant.likely-s3s/WqlpOiPyB63q8FvJNQ@xxxxxxxxxxxxxxxx>
> Cc: devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@xxxxxxxxxxxxxxxx
> Cc: Rob Herring <rob.herring-bsGFqQB8/DxBDgjK7y7TUQ@xxxxxxxxxxxxxxxx>
> ---
> arch/arc/Kconfig | 9 +++++
> arch/arc/Makefile | 9 +++++
> arch/arc/boot/dts/Makefile | 14 ++++++++
> arch/arc/boot/dts/skeleton.dts | 10 ++++++
> arch/arc/boot/dts/skeleton.dtsi | 21 ++++++++++++
> arch/arc/include/asm/prom.h | 15 ++++++++
> arch/arc/include/asm/sections.h | 1 +
> arch/arc/kernel/Makefile | 2 +
> arch/arc/kernel/devtree.c | 69 +++++++++++++++++++++++++++++++++++++++
> arch/arc/kernel/setup.c | 9 +++++
> arch/arc/mm/init.c | 13 +++++++
> 11 files changed, 172 insertions(+), 0 deletions(-)
> create mode 100644 arch/arc/boot/dts/Makefile
> create mode 100644 arch/arc/boot/dts/skeleton.dts
> create mode 100644 arch/arc/boot/dts/skeleton.dtsi
> create mode 100644 arch/arc/include/asm/prom.h
> create mode 100644 arch/arc/kernel/devtree.c
>
> diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
> index a353849..7666857 100644
> --- a/arch/arc/Kconfig
> +++ b/arch/arc/Kconfig
> @@ -24,8 +24,11 @@ config ARC
> select GENERIC_SMP_IDLE_THREAD
> select HAVE_GENERIC_HARDIRQS
> select HAVE_MEMBLOCK
> + select IRQ_DOMAIN
> select MODULES_USE_ELF_RELA
> select NO_BOOTMEM
> + select OF
> + select OF_EARLY_FLATTREE
>
> config SCHED_OMIT_FRAME_POINTER
> def_bool y
> @@ -320,6 +323,12 @@ config CMDLINE_UBOOT
> to it. kernel startup code will copy the string into cmdline buffer
> and also append CONFIG_CMDLINE.
>
> +config ARC_BUILTIN_DTB_NAME
> + string "Built in DTB"
> + help
> + Set the name of the DTB to embed in the vmlinux binary
> + Leaving it blank selects the minimal "skeleton" dtb
> +
> source "kernel/Kconfig.preempt"
>
> endmenu # "ARC Architecture Configuration"
> diff --git a/arch/arc/Makefile b/arch/arc/Makefile
> index 4d52a3b..90570f9 100644
> --- a/arch/arc/Makefile
> +++ b/arch/arc/Makefile
> @@ -83,6 +83,9 @@ head-y := arch/arc/kernel/head.o
> # See arch/arc/Kbuild for content of core part of the kernel
> core-y += arch/arc/
>
> +# w/o this dtb won't embed into kernel binary
> +core-y += arch/arc/boot/dts/
> +
> # w/o this ifneq, make ARCH=arc clean was crapping out
> ifneq ($(platform-y),)
> core-y += arch/arc/plat-$(PLATFORM)/
> @@ -101,6 +104,12 @@ bootpImage: vmlinux
> uImage: vmlinux
> $(Q)$(MAKE) $(build)=$(boot) $(boot)/$@
>
> +%.dtb %.dtb.S %.dtb.o:
> + $(Q)$(MAKE) $(build)=$(boot)/dts $(boot)/dts/$@
> +
> +dtbs:
> + $(Q)$(MAKE) $(build)=$(boot)/dts $(boot)/dts/$@
> +
> archclean:
> $(Q)$(MAKE) $(clean)=$(boot)
>
> diff --git a/arch/arc/boot/dts/Makefile b/arch/arc/boot/dts/Makefile
> new file mode 100644
> index 0000000..4a972a3
> --- /dev/null
> +++ b/arch/arc/boot/dts/Makefile
> @@ -0,0 +1,14 @@
> +ifeq ($(CONFIG_OF),y)
> +
> +# Built-in dtb
> +builtindtb-y := skeleton
> +
> +ifneq ($(CONFIG_ARC_BUILTIN_DTB_NAME),"")
> + builtindtb-y := $(CONFIG_ARC_BUILTIN_DTB_NAME)
> +endif
> +
> +obj-y += $(patsubst "%",%,$(builtindtb-y)).dtb.o
> +
> +clean-files := *.dtb
> +
> +endif
> diff --git a/arch/arc/boot/dts/skeleton.dts b/arch/arc/boot/dts/skeleton.dts
> new file mode 100644
> index 0000000..25a84fb
> --- /dev/null
> +++ b/arch/arc/boot/dts/skeleton.dts
> @@ -0,0 +1,10 @@
> +/*
> + * Copyright (C) 2012 Synopsys, Inc. (www.synopsys.com)
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +/dts-v1/;
> +
> +/include/ "skeleton.dtsi"
> diff --git a/arch/arc/boot/dts/skeleton.dtsi b/arch/arc/boot/dts/skeleton.dtsi
> new file mode 100644
> index 0000000..9b357d8
> --- /dev/null
> +++ b/arch/arc/boot/dts/skeleton.dtsi
> @@ -0,0 +1,21 @@
> +/*
> + * Copyright (C) 2012 Synopsys, Inc. (www.synopsys.com)
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +
> +/*
> + * Skeleton device tree; the bare minimum needed to boot; just include and
> + * add a compatible value.
> + */
> +
> +/ {
> + compatible = "snps,arc";
> + #address-cells = <1>;
> + #size-cells = <1>;
> + chosen { };
> + aliases { };
> + memory { device_type = "memory"; reg = <0 0>; };
> +};
> diff --git a/arch/arc/include/asm/prom.h b/arch/arc/include/asm/prom.h
> new file mode 100644
> index 0000000..f54489b
> --- /dev/null
> +++ b/arch/arc/include/asm/prom.h
> @@ -0,0 +1,15 @@
> +/*
> + * Copyright (C) 2012 Synopsys, Inc. (www.synopsys.com)
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +
> +#ifndef _ASM_ARC_PROM_H_
> +#define _ASM_ARC_PROM_H_
> +
> +#define HAVE_ARCH_DEVTREE_FIXUPS
> +extern int __init setup_machine_fdt(void *dt);
> +
> +#endif
> diff --git a/arch/arc/include/asm/sections.h b/arch/arc/include/asm/sections.h
> index fc15f2e..6fc1159 100644
> --- a/arch/arc/include/asm/sections.h
> +++ b/arch/arc/include/asm/sections.h
> @@ -13,5 +13,6 @@
>
> extern char _int_vec_base_lds[];
> extern char __arc_dccm_base[];
> +extern char __dtb_start[];
>
> #endif
> diff --git a/arch/arc/kernel/Makefile b/arch/arc/kernel/Makefile
> index 6d83431..8a55e99 100644
> --- a/arch/arc/kernel/Makefile
> +++ b/arch/arc/kernel/Makefile
> @@ -8,6 +8,8 @@
> obj-y := arcksyms.o setup.o irq.o time.o reset.o ptrace.o entry.o process.o
> obj-y += signal.o traps.o sys.o troubleshoot.o stacktrace.o clk.o
>
> +obj-$(CONFIG_OF) += devtree.o
> +
> obj-$(CONFIG_ARC_FPU_SAVE_RESTORE) += fpu.o
> CFLAGS_fpu.o += -mdpfp
>
> diff --git a/arch/arc/kernel/devtree.c b/arch/arc/kernel/devtree.c
> new file mode 100644
> index 0000000..229f78e
> --- /dev/null
> +++ b/arch/arc/kernel/devtree.c
> @@ -0,0 +1,69 @@
> +/*
> + * Copyright (C) 2012 Synopsys, Inc. (www.synopsys.com)
> + *
> + * Based on highly stipped down version of METAG
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +
> +
> +#include <linux/init.h>
> +#include <linux/export.h>
> +#include <linux/errno.h>
> +#include <linux/types.h>
> +#include <linux/reboot.h>
> +#include <linux/memblock.h>
> +#include <linux/of.h>
> +#include <linux/of_fdt.h>
> +#include <linux/of_irq.h>
> +#include <linux/of_platform.h>
> +#include <asm/prom.h>
> +
> +/* called from unflatten_device_tree() to bootstrap devicetree itself */
> +void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
> +{
> + return __va(memblock_alloc(size, align));
> +}
> +
> +/**
> + * setup_machine_fdt - Machine setup when an dtb was passed to the kernel
> + * @dt: virtual address pointer to dt blob
> + *
> + * If a dtb was passed to the kernel, then use it to choose the correct
> + * machine_desc and to setup the system.
> + */
> +int __init setup_machine_fdt(void *dt)
> +{
> + struct boot_param_header *devtree = dt;
> + unsigned long dt_root;
> + char *model, *compat;
> + char manufacturer[16];
> +
> + /* check device tree validity */
> + if (be32_to_cpu(devtree->magic) != OF_DT_HEADER)
> + return 1;
> +
> + /* Search the mdescs for the 'best' compatible value match */
> + initial_boot_params = devtree;
> + dt_root = of_get_flat_dt_root();
> +
> + /* compat = "<manufacturer>,<model>" */
> + compat = of_get_flat_dt_prop(dt_root, "compatible", NULL);
> + if (!compat)
> + compat = "<unknown>";
> +
> + model = strchr(compat, ',');
> + if (model)
> + model++;
> +
> + strlcpy(manufacturer, compat, model ? model - compat : strlen(compat));
> +
> + pr_info("Board \"%s\" from %s (Manufacturer)\n", model, manufacturer);
> +
> + /* Retrieve various information from the /chosen node */
> + of_scan_flat_dt(early_init_dt_scan_chosen, boot_command_line);
> +
> + return 0;
> +}
> diff --git a/arch/arc/kernel/setup.c b/arch/arc/kernel/setup.c
> index 82ac206..27aebd6 100644
> --- a/arch/arc/kernel/setup.c
> +++ b/arch/arc/kernel/setup.c
> @@ -13,6 +13,8 @@
> #include <linux/console.h>
> #include <linux/module.h>
> #include <linux/cpu.h>
> +#include <linux/of_fdt.h>
> +#include <asm/sections.h>
> #include <asm/arcregs.h>
> #include <asm/tlb.h>
> #include <asm/cache.h>
> @@ -20,6 +22,7 @@
> #include <asm/page.h>
> #include <asm/irq.h>
> #include <asm/arcregs.h>
> +#include <asm/prom.h>
>
> #define FIX_PTR(x) __asm__ __volatile__(";" : "+r"(x))
>
> @@ -57,6 +60,8 @@ void __init __attribute__((weak)) arc_platform_early_init(void)
>
> void __init setup_arch(char **cmdline_p)
> {
> + int rc;
> +
> #ifdef CONFIG_CMDLINE_UBOOT
> /* Make sure that a whitespace is inserted before */
> strlcat(command_line, " ", sizeof(command_line));
> @@ -71,6 +76,8 @@ void __init setup_arch(char **cmdline_p)
> strlcpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
> *cmdline_p = command_line;
>
> + rc = setup_machine_fdt(__dtb_start);
> +
> /* To force early parsing of things like mem=xxx */
> parse_early_param();
>
> @@ -81,6 +88,8 @@ void __init setup_arch(char **cmdline_p)
>
> setup_arch_memory();
>
> + unflatten_device_tree();
> +
> /* Can be issue if someone passes cmd line arg "ro"
> * But that is unlikely so keeping it as it is
> */
> diff --git a/arch/arc/mm/init.c b/arch/arc/mm/init.c
> index 63da347..682cf57 100644
> --- a/arch/arc/mm/init.c
> +++ b/arch/arc/mm/init.c
> @@ -39,6 +39,11 @@ static int __init setup_mem_sz(char *str)
> }
> early_param("mem", setup_mem_sz);
>
> +void __init early_init_dt_add_memory_arch(u64 base, u64 size)
> +{
> + pr_err("%s(%llx, %llx)\n", __func__, base, size);
> +}
> +
> /*
> * First memory setup routine called from setup_arch()
> * 1. setup swapper's mm @init_mm
> @@ -169,3 +174,11 @@ void __init free_initrd_mem(unsigned long start, unsigned long end)
> free_init_pages("initrd memory", start, end);
> }
> #endif
> +
> +#ifdef CONFIG_OF_FLATTREE
> +void __init early_init_dt_setup_initrd_arch(unsigned long start,
> + unsigned long end)
> +{
> + pr_err("%s(%lx, %lx)\n", __func__, start, end);
> +}
> +#endif /* CONFIG_OF_FLATTREE */
>
Does the reworked patch look OK to you ? If so, can I get your ACK please.
Thx,
-Vineet
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