diff options
Diffstat (limited to 'arch/arm')
| -rw-r--r-- | arch/arm/Kconfig | 12 | ||||
| -rw-r--r-- | arch/arm/boot/compressed/.gitignore | 9 | ||||
| -rw-r--r-- | arch/arm/boot/compressed/Makefile | 21 | ||||
| -rw-r--r-- | arch/arm/boot/compressed/atags_to_fdt.c | 97 | ||||
| -rw-r--r-- | arch/arm/boot/compressed/head.S | 32 | ||||
| -rw-r--r-- | arch/arm/boot/compressed/libfdt_env.h | 15 |
6 files changed, 184 insertions, 2 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index fc9d147ae30e..bc3e8dc005bb 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -1960,6 +1960,18 @@ config ARM_APPENDED_DTB location into r2 of a bootloader provided DTB is always preferable to this option. +config ARM_ATAG_DTB_COMPAT + bool "Supplement the appended DTB with traditional ATAG information" + depends on ARM_APPENDED_DTB + help + Some old bootloaders can't be updated to a DTB capable one, yet + they provide ATAGs with memory configuration, the ramdisk address, + the kernel cmdline string, etc. Such information is dynamically + provided by the bootloader and can't always be stored in a static + DTB. To allow a device tree enabled kernel to be used with such + bootloaders, this option allows zImage to extract the information + from the ATAG list and store it at run time into the appended DTB. + config CMDLINE string "Default kernel command string" default "" diff --git a/arch/arm/boot/compressed/.gitignore b/arch/arm/boot/compressed/.gitignore index c6028967d336..e0936a148516 100644 --- a/arch/arm/boot/compressed/.gitignore +++ b/arch/arm/boot/compressed/.gitignore @@ -5,3 +5,12 @@ piggy.lzo piggy.lzma vmlinux vmlinux.lds + +# borrowed libfdt files +fdt.c +fdt.h +fdt_ro.c +fdt_rw.c +fdt_wip.c +libfdt.h +libfdt_internal.h diff --git a/arch/arm/boot/compressed/Makefile b/arch/arm/boot/compressed/Makefile index c20ddc69d950..55f86349d547 100644 --- a/arch/arm/boot/compressed/Makefile +++ b/arch/arm/boot/compressed/Makefile @@ -93,19 +93,36 @@ suffix_$(CONFIG_KERNEL_GZIP) = gzip suffix_$(CONFIG_KERNEL_LZO) = lzo suffix_$(CONFIG_KERNEL_LZMA) = lzma +# Borrowed libfdt files for the ATAG compatibility mode + +libfdt := fdt_rw.c fdt_ro.c fdt_wip.c fdt.c +libfdt_hdrs := fdt.h libfdt.h libfdt_internal.h + +libfdt_objs := $(addsuffix .o, $(basename $(libfdt))) + +$(addprefix $(obj)/,$(libfdt) $(libfdt_hdrs)): $(obj)/%: $(srctree)/scripts/dtc/libfdt/% + $(call cmd,shipped) + +$(addprefix $(obj)/,$(libfdt_objs) atags_to_fdt.o): \ + $(addprefix $(obj)/,$(libfdt_hdrs)) + +ifeq ($(CONFIG_ARM_ATAG_DTB_COMPAT),y) +OBJS += $(libfdt_objs) atags_to_fdt.o +endif + targets := vmlinux vmlinux.lds \ piggy.$(suffix_y) piggy.$(suffix_y).o \ font.o font.c head.o misc.o $(OBJS) # Make sure files are removed during clean -extra-y += piggy.gzip piggy.lzo piggy.lzma lib1funcs.S +extra-y += piggy.gzip piggy.lzo piggy.lzma lib1funcs.S $(libfdt) $(libfdt_hdrs) ifeq ($(CONFIG_FUNCTION_TRACER),y) ORIG_CFLAGS := $(KBUILD_CFLAGS) KBUILD_CFLAGS = $(subst -pg, , $(ORIG_CFLAGS)) endif -ccflags-y := -fpic -fno-builtin +ccflags-y := -fpic -fno-builtin -I$(obj) asflags-y := -Wa,-march=all # Supply kernel BSS size to the decompressor via a linker symbol. diff --git a/arch/arm/boot/compressed/atags_to_fdt.c b/arch/arm/boot/compressed/atags_to_fdt.c new file mode 100644 index 000000000000..6ce11c481178 --- /dev/null +++ b/arch/arm/boot/compressed/atags_to_fdt.c @@ -0,0 +1,97 @@ +#include <asm/setup.h> +#include <libfdt.h> + +static int node_offset(void *fdt, const char *node_path) +{ + int offset = fdt_path_offset(fdt, node_path); + if (offset == -FDT_ERR_NOTFOUND) + offset = fdt_add_subnode(fdt, 0, node_path); + return offset; +} + +static int setprop(void *fdt, const char *node_path, const char *property, + uint32_t *val_array, int size) +{ + int offset = node_offset(fdt, node_path); + if (offset < 0) + return offset; + return fdt_setprop(fdt, offset, property, val_array, size); +} + +static int setprop_string(void *fdt, const char *node_path, + const char *property, const char *string) +{ + int offset = node_offset(fdt, node_path); + if (offset < 0) + return offset; + return fdt_setprop_string(fdt, offset, property, string); +} + +static int setprop_cell(void *fdt, const char *node_path, + const char *property, uint32_t val) +{ + int offset = node_offset(fdt, node_path); + if (offset < 0) + return offset; + return fdt_setprop_cell(fdt, offset, property, val); +} + +/* + * Convert and fold provided ATAGs into the provided FDT. + * + * REturn values: + * = 0 -> pretend success + * = 1 -> bad ATAG (may retry with another possible ATAG pointer) + * < 0 -> error from libfdt + */ +int atags_to_fdt(void *atag_list, void *fdt, int total_space) +{ + struct tag *atag = atag_list; + uint32_t mem_reg_property[2 * NR_BANKS]; + int memcount = 0; + int ret; + + /* make sure we've got an aligned pointer */ + if ((u32)atag_list & 0x3) + return 1; + + /* if we get a DTB here we're done already */ + if (*(u32 *)atag_list == fdt32_to_cpu(FDT_MAGIC)) + return 0; + + /* validate the ATAG */ + if (atag->hdr.tag != ATAG_CORE || + (atag->hdr.size != tag_size(tag_core) && + atag->hdr.size != 2)) + return 1; + + /* let's give it all the room it could need */ + ret = fdt_open_into(fdt, fdt, total_space); + if (ret < 0) + return ret; + + for_each_tag(atag, atag_list) { + if (atag->hdr.tag == ATAG_CMDLINE) { + setprop_string(fdt, "/chosen", "bootargs", + atag->u.cmdline.cmdline); + } else if (atag->hdr.tag == ATAG_MEM) { + if (memcount >= sizeof(mem_reg_property)/4) + continue; + mem_reg_property[memcount++] = cpu_to_fdt32(atag->u.mem.start); + mem_reg_property[memcount++] = cpu_to_fdt32(atag->u.mem.size); + } else if (atag->hdr.tag == ATAG_INITRD2) { + uint32_t initrd_start, initrd_size; + initrd_start = atag->u.initrd.start; + initrd_size = atag->u.initrd.size; + setprop_cell(fdt, "/chosen", "linux,initrd-start", + initrd_start); + setprop_cell(fdt, "/chosen", "linux,initrd-end", + initrd_start + initrd_size); + } + } + + if (memcount) + setprop(fdt, "/memory", "reg", mem_reg_property, 4*memcount); + + return fdt_pack(fdt); +} diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S index e2d933fa36ab..e45767851a4c 100644 --- a/arch/arm/boot/compressed/head.S +++ b/arch/arm/boot/compressed/head.S @@ -246,6 +246,38 @@ restart: adr r0, LC0 cmp lr, r1 bne dtb_check_done @ not found +#ifdef CONFIG_ARM_ATAG_DTB_COMPAT + /* + * OK... Let's do some funky business here. + * If we do have a DTB appended to zImage, and we do have + * an ATAG list around, we want the later to be translated + * and folded into the former here. To be on the safe side, + * let's temporarily move the stack away into the malloc + * area. No GOT fixup has occurred yet, but none of the + * code we're about to call uses any global variable. + */ + add sp, sp, #0x10000 + stmfd sp!, {r0-r3, ip, lr} + mov r0, r8 + mov r1, r6 + sub r2, sp, r6 + bl atags_to_fdt + + /* + * If returned value is 1, there is no ATAG at the location + * pointed by r8. Try the typical 0x100 offset from start + * of RAM and hope for the best. + */ + cmp r0, #1 + sub r0, r4, #(TEXT_OFFSET - 0x100) + mov r1, r6 + sub r2, sp, r6 + blne atags_to_fdt + + ldmfd sp!, {r0-r3, ip, lr} + sub sp, sp, #0x10000 +#endif + mov r8, r6 @ use the appended device tree /* diff --git a/arch/arm/boot/compressed/libfdt_env.h b/arch/arm/boot/compressed/libfdt_env.h new file mode 100644 index 000000000000..1f4e71876b00 --- /dev/null +++ b/arch/arm/boot/compressed/libfdt_env.h @@ -0,0 +1,15 @@ +#ifndef _ARM_LIBFDT_ENV_H +#define _ARM_LIBFDT_ENV_H + +#include <linux/types.h> +#include <linux/string.h> +#include <asm/byteorder.h> + +#define fdt16_to_cpu(x) be16_to_cpu(x) +#define cpu_to_fdt16(x) cpu_to_be16(x) +#define fdt32_to_cpu(x) be32_to_cpu(x) +#define cpu_to_fdt32(x) cpu_to_be32(x) +#define fdt64_to_cpu(x) be64_to_cpu(x) +#define cpu_to_fdt64(x) cpu_to_be64(x) + +#endif |