[RFC 2/2] ARM:boot:device tree: Merge specific atags into the device tree
Grant Likely
grant.likely at secretlab.ca
Fri Feb 4 15:59:38 EST 2011
On Feb 3, 2011 9:44 PM, "Nicolas Pitre" <nico at fluxnic.net> wrote:
>
> On Wed, 26 Jan 2011, John Bonesio wrote:
>
> > This patch is to merge in key atags into the appended device tree. An
appended
> > device tree is where the zImage has a dtb binary appended at the end of
it. The
> > boot code looks for an appended device tree, then looks for a few key
atags
> > passed in by the bootloader.
> >
> > The bootargs and memory size settings, if they exist, override existing
values
> > in the appended device tree. If these values don't currently exist in
the
> > appended device tree, they are added.
> >
> > Signed-off-by: John Bonesio <bones at secretlab.ca>
> > Acked-by: Grant Likely <grant.likely at secretlab.ca>
>
> This is just for testing/evaluation purpose and not intended to be
> merged upstream at some point, right?
Correct.
>
> > ---
> >
> > arch/arm/boot/compressed/Makefile | 31 +++++++++++++++++---
> > arch/arm/boot/compressed/atags.c | 50
++++++++++++++++++++++++++++++++
> > arch/arm/boot/compressed/head.S | 7 ++++
> > arch/arm/boot/compressed/misc.c | 58
++++++++++++++++++++++++++++++++++++-
> > 4 files changed, 139 insertions(+), 7 deletions(-)
> > create mode 100644 arch/arm/boot/compressed/atags.c
> >
> > diff --git a/arch/arm/boot/compressed/Makefile
b/arch/arm/boot/compressed/Makefile
> > index 0a8f748..7978a39 100644
> > --- a/arch/arm/boot/compressed/Makefile
> > +++ b/arch/arm/boot/compressed/Makefile
> > @@ -49,6 +49,10 @@ ifeq ($(CONFIG_ARCH_SHMOBILE),y)
> > OBJS += head-shmobile.o
> > endif
> >
> > +ifeq ($(CONFIG_ARM_APPENDED_DTB),y)
> > +OBJS += atags.o libfdt.a
> > +endif
> > +
> > #
> > # We now have a PIC decompressor implementation. Decompressors running
> > # from RAM should not define ZTEXTADDR. Decompressors running directly
> > @@ -80,7 +84,9 @@ ORIG_CFLAGS := $(KBUILD_CFLAGS)
> > KBUILD_CFLAGS = $(subst -pg, , $(ORIG_CFLAGS))
> > endif
> >
> > -EXTRA_CFLAGS := -fpic -fno-builtin
> > +fdttree := $(srctree)/scripts/dtc/libfdt
> > +
> > +EXTRA_CFLAGS := -fpic -fno-builtin -I$(fdttree) -I$(obj)
> > EXTRA_AFLAGS := -Wa,-march=all
> >
> > # Supply ZRELADDR to the decompressor via a linker symbol.
> > @@ -100,13 +106,28 @@ LDFLAGS_vmlinux += -X
> > LDFLAGS_vmlinux += -T
> >
> > # For __aeabi_uidivmod
> > -lib1funcs = $(obj)/lib1funcs.o
> > +libfuncs = $(obj)/lib1funcs.o
> >
> > -$(obj)/lib1funcs.S: $(srctree)/arch/$(SRCARCH)/lib/lib1funcs.S FORCE
> > - $(call cmd,shipped)
> > +ifeq ($(CONFIG_ARM_APPENDED_DTB),y)
> > +# For memchr, memmove, etc
> > +libfuncs += $(obj)/memchr.o $(obj)/strchr.o $(obj)/memmove.o
$(obj)/memzero.o
> > +endif
> > +
> > +
> > +libfdtheader := $(fdttree)/fdt.h $(fdttree)/libfdt.h
$(fdttree)/libfdt_internal.h
> > +libfdtobj := $(obj)/fdt.o $(obj)/fdt_ro.o $(obj)/fdt_wip.o
$(obj)/fdt_sw.o $(obj)/fdt_rw.o $(obj)/fdt_strerror.o
> > +
> > +$(libfdtobj): $(obj)/%.o: $(srctree)/scripts/dtc/libfdt/%.c
$(libfdtheader)
> > + $(call cmd_cc_o_c)
> > +
> > +$(obj)/libfdt.a: $(libfdtobj)
> > + $(AR) rcs $@ $^
> > +
> > +$(libfuncs): $(obj)/%.o: $(srctree)/arch/$(SRCARCH)/lib/%.S
> > + $(call cmd_as_o_S)
> >
> > $(obj)/vmlinux: $(obj)/vmlinux.lds $(obj)/$(HEAD)
$(obj)/piggy.$(suffix_y).o \
> > - $(addprefix $(obj)/, $(OBJS)) $(lib1funcs) FORCE
> > + $(addprefix $(obj)/, $(OBJS)) $(libfuncs) FORCE
> > $(call if_changed,ld)
> > @:
> >
> > diff --git a/arch/arm/boot/compressed/atags.c
b/arch/arm/boot/compressed/atags.c
> > new file mode 100644
> > index 0000000..e37d8de
> > --- /dev/null
> > +++ b/arch/arm/boot/compressed/atags.c
> > @@ -0,0 +1,50 @@
> > +#include <stddef.h>
> > +#include <asm/byteorder.h>
> > +#include <asm/setup.h>
> > +#include <fdt.h>
> > +#include <libfdt.h>
> > +
> > +
> > +int dt_setprop(void *fdt, const char *node_path, const char *property,
> > + uint32_t *val_array, int size)
> > +{
> > + int offset;
> > +
> > + offset = fdt_path_offset(fdt, node_path);
> > + if (offset < 0)
> > + return offset;
> > +
> > + return fdt_setprop(fdt, offset, property, val_array, size);
> > +}
> > +
> > +int dt_setprop_string(void *fdt, const char *node_path,
> > + const char *property, const char *string)
> > +{
> > + int offset;
> > +
> > + offset = fdt_path_offset(fdt, node_path);
> > + if (offset < 0)
> > + return offset;
> > +
> > + return fdt_setprop_string(fdt, offset, property, string);
> > +}
> > +
> > +void dt_merge_atags(void *dt, void *ataglist)
> > +{
> > + struct tag *atag = ataglist;
> > + uint32_t mem_reg_property[2];
> > +
> > + while (atag && atag->hdr.tag != 0) {
> > + if (atag->hdr.tag == ATAG_CMDLINE) {
> > + dt_setprop_string(dt, "/chosen", "bootargs",
> > + atag->u.cmdline.cmdline);
> > + } else if (atag->hdr.tag == ATAG_MEM) {
> > + mem_reg_property[0] =
cpu_to_fdt32(atag->u.mem.start);
> > + mem_reg_property[1] =
cpu_to_fdt32(atag->u.mem.size);
> > + dt_setprop(dt, "/memory", "reg", mem_reg_property,
> > + sizeof(mem_reg_property));
> > + }
> > + atag = tag_next(atag);
> > + }
> > +}
> > +
> > diff --git a/arch/arm/boot/compressed/head.S
b/arch/arm/boot/compressed/head.S
> > index db860b3..09e659d 100644
> > --- a/arch/arm/boot/compressed/head.S
> > +++ b/arch/arm/boot/compressed/head.S
> > @@ -257,6 +257,13 @@ not_relocated:
> > cmp r1, r9
> > bne keep_atags
> >
> > + /* Merge some of the atags into the device tree */
> > + push {r2, r3, r10, r11}
> > + mov r0, r2
> > + mov r1, r8
> > + bl dt_merge_atags
> > + pop {r2, r3, r10, r11}
> > +
> > /* copy the device tree binary to 0x0 */
> > ldr r9, [r10, #4] @ device tree size
> >
> > diff --git a/arch/arm/boot/compressed/misc.c
b/arch/arm/boot/compressed/misc.c
> > index e653a6d..2d4da4c 100644
> > --- a/arch/arm/boot/compressed/misc.c
> > +++ b/arch/arm/boot/compressed/misc.c
> > @@ -29,7 +29,7 @@ unsigned int __machine_arch_type;
> > #include <asm/unaligned.h>
> >
> >
> > -static void putstr(const char *ptr);
> > +void putstr(const char *ptr);
> > extern void error(char *x);
> >
> > #include <mach/uncompress.h>
> > @@ -100,7 +100,7 @@ static void icedcc_putc(int ch)
> > #define putc(ch) icedcc_putc(ch)
> > #endif
> >
> > -static void putstr(const char *ptr)
> > +void putstr(const char *ptr)
> > {
> > char c;
> >
> > @@ -114,6 +114,60 @@ static void putstr(const char *ptr)
> > }
> >
> >
> > +#ifdef CONFIG_ARM_APPENDED_DTB
> > +/**
> > + * strlen - Find the length of a string
> > + * @s: The string to be sized
> > + */
> > +size_t strlen(const char *s)
> > +{
> > + const char *sc;
> > +
> > + for (sc = s; *sc != '\0'; ++sc)
> > + /* nothing */;
> > + return sc - s;
> > +}
> > +
> > +/**
> > + * strcmp - Compare two strings
> > + * @cs: One string
> > + * @ct: Another string
> > + */
> > +#undef strcmp
> > +int strcmp(const char *cs, const char *ct)
> > +{
> > + unsigned char c1, c2;
> > +
> > + while (1) {
> > + c1 = *cs++;
> > + c2 = *ct++;
> > + if (c1 != c2)
> > + return c1 < c2 ? -1 : 1;
> > + if (!c1)
> > + break;
> > + }
> > + return 0;
> > +}
> > +
> > +/**
> > + * memcmp - Compare two areas of memory
> > + * @cs: One area of memory
> > + * @ct: Another area of memory
> > + * @count: The size of the area.
> > + */
> > +#undef memcmp
> > +int memcmp(const void *cs, const void *ct, size_t count)
> > +{
> > + const unsigned char *su1, *su2;
> > + int res = 0;
> > +
> > + for (su1 = cs, su2 = ct; 0 < count; ++su1, ++su2, count--)
> > + if ((res = *su1 - *su2) != 0)
> > + break;
> > + return res;
> > +}
> > +#endif
> > +
> > void *memcpy(void *__dest, __const void *__src, size_t __n)
> > {
> > int i = 0;
> >
> >
> > _______________________________________________
> > linux-arm-kernel mailing list
> > linux-arm-kernel at lists.infradead.org
> > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
> >
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