CC devicetree On Sat, Mar 26, 2016 at 2:47 AM, Rich Felker <dalias@xxxxxxxx> wrote: > Signed-off-by: Rich Felker <dalias@xxxxxxxx> > --- > > I'd like to add this patch to the new device tree support to ease the > transition to device tree on legacy hardware where replacing the > bootloader with a new one that can pass a DTB may be extra work. Since > I'm not familiar with this kind of build system change, though, I'd > like some feedback on whether I'm doing it right. Alternatively, you could append the DTB to the boot image. Cfr. http://elinux.org/R-Car/Boards/Marzen http://elinux.org/Dragonboard/APQ8074 > arch/sh/Kconfig | 20 ++++++++++++++++++++ > arch/sh/Makefile | 2 ++ > arch/sh/boards/of-generic.c | 15 ++++++++++++--- > arch/sh/boot/dts/Makefile | 3 +++ > arch/sh/kernel/setup.c | 4 ++++ > 5 files changed, 41 insertions(+), 3 deletions(-) > create mode 100644 arch/sh/boot/dts/Makefile > > diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig > index 9dec535..b6db094 100644 > --- a/arch/sh/Kconfig > +++ b/arch/sh/Kconfig > @@ -755,6 +755,26 @@ endmenu > > menu "Boot options" > > +config USE_BUILTIN_DTB > + bool "Use builtin DTB" > + default n > + depends on SH_DEVICE_TREE > + help > + Link a device tree blob for particular hardware into the kernel, > + suppressing use of the DTB pointer provided by the bootloader. > + This option should only be used with legacy bootloaders that are > + not capable of providing a DTB to the kernel, or for experimental > + hardware without stable device tree bindings. > + > +config BUILTIN_DTB_SOURCE > + string "Source file for builtin DTB" > + default "" > + depends on USE_BUILTIN_DTB > + help > + Base name (without suffix, relative to arch/sh/boot/dts) for the > + a DTS file that will be used to produce the DTB linked into the drop the first word "a" > + kernel. > + > config ZERO_PAGE_OFFSET > hex > default "0x00010000" if PAGE_SIZE_64KB || SH_RTS7751R2D || \ > diff --git a/arch/sh/Makefile b/arch/sh/Makefile > index 3566a759..0047666 100644 > --- a/arch/sh/Makefile > +++ b/arch/sh/Makefile > @@ -131,6 +131,8 @@ head-y := arch/sh/kernel/head_$(BITS).o > core-y += arch/sh/kernel/ arch/sh/mm/ arch/sh/boards/ > core-$(CONFIG_SH_FPU_EMU) += arch/sh/math-emu/ > > +core-$(CONFIG_USE_BUILTIN_DTB) += arch/sh/boot/dts/ > + > # Mach groups > machdir-$(CONFIG_SOLUTION_ENGINE) += mach-se > machdir-$(CONFIG_SH_HP6XX) += mach-hp6xx > diff --git a/arch/sh/boards/of-generic.c b/arch/sh/boards/of-generic.c > index bf3a166..57d45dc 100644 > --- a/arch/sh/boards/of-generic.c > +++ b/arch/sh/boards/of-generic.c > @@ -126,13 +126,22 @@ static void __init sh_of_time_init(void) > > static void __init sh_of_setup(char **cmdline_p) > { > + struct device_node *root; > + > +#ifdef CONFIG_USE_BUILTIN_DTB > + unflatten_and_copy_device_tree(); > +#else > unflatten_device_tree(); > +#endif > > board_time_init = sh_of_time_init; > > - sh_mv.mv_name = of_flat_dt_get_machine_name(); > - if (!sh_mv.mv_name) > - sh_mv.mv_name = "Unknown SH model"; > + sh_mv.mv_name = "Unknown SH model"; > + root = of_find_node_by_path("/"); > + if (root) { > + of_property_read_string(root, "model", &sh_mv.mv_name); > + of_node_put(root); > + } > > sh_of_smp_probe(); > } > diff --git a/arch/sh/boot/dts/Makefile b/arch/sh/boot/dts/Makefile > new file mode 100644 > index 0000000..e5ce3a0 > --- /dev/null > +++ b/arch/sh/boot/dts/Makefile > @@ -0,0 +1,3 @@ > +obj-$(CONFIG_USE_BUILTIN_DTB) += $(patsubst "%",%,$(CONFIG_BUILTIN_DTB_SOURCE)).dtb.o > + > +clean-files := *.dtb.S > diff --git a/arch/sh/kernel/setup.c b/arch/sh/kernel/setup.c > index efb60ce..ec7c99f 100644 > --- a/arch/sh/kernel/setup.c > +++ b/arch/sh/kernel/setup.c > @@ -251,7 +251,11 @@ void __ref sh_fdt_init(phys_addr_t dt_phys) > /* Avoid calling an __init function on secondary cpus. */ > if (done) return; > > +#ifdef CONFIG_USE_BUILTIN_DTB > + dt_virt = __dtb_start; > +#else > dt_virt = phys_to_virt(dt_phys); > +#endif > > if (!dt_virt || !early_init_dt_scan(dt_virt)) { > pr_crit("Error: invalid device tree blob" Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
