[U-Boot] [PATCH 8/8] mips: bmips: add support for raw .elf images

[Álvaro Fernández Rojas]

Hi,

El 15/04/2017 a las 20:54, Daniel Schwierzeck escribió:
> 
> 
> Am 15.04.2017 um 20:10 schrieb Álvaro Fernández Rojas:
>> Hi,
>>
>> El 15/04/2017 a las 19:19, Álvaro Fernández Rojas escribió:
>>>
>>>
>>> El 14/04/2017 a las 21:05, Daniel Schwierzeck escribió:
>>>>
>>>>
>>>> Am 13.04.2017 um 17:52 schrieb Álvaro Fernández Rojas:
>>>>> CFE supports loading .elf images instead of raw binaries.
>>>>>
>>>>> Signed-off-by: Álvaro Fernández Rojas <noltari at gmail.com>
>>>>> ---
>>>>>  Makefile                     | 22 ++++++++++++++++++++++
>>>>>  arch/mips/cpu/u-boot-elf.lds | 10 ++++++++++
>>>>>  2 files changed, 32 insertions(+)
>>>>>  create mode 100644 arch/mips/cpu/u-boot-elf.lds
>>>>>
>>>>> diff --git a/Makefile b/Makefile
>>>>> index 09b597d..667b5f2 100644
>>>>> --- a/Makefile
>>>>> +++ b/Makefile
>>>>> @@ -568,6 +568,15 @@ ifndef LDSCRIPT
>>>>>  	endif
>>>>>  endif
>>>>>  
>>>>> +ifndef LDSCRIPT_ELF
>>>>> +	ifeq ($(wildcard $(LDSCRIPT_ELF)),)
>>>>> +		LDSCRIPT_ELF := $(srctree)/$(CPUDIR)/u-boot-elf.lds
>>>>> +	endif
>>>>> +	ifeq ($(wildcard $(LDSCRIPT_ELF)),)
>>>>> +		LDSCRIPT_ELF := $(srctree)/arch/$(ARCH)/cpu/u-boot-elf.lds
>>>>> +	endif
>>>>> +endif
>>>>
>>>> could you try to build the ELF binary without a custom linker script? I
>>>> think the built-in one should work too.
>>>>
>>>>> +
>>>>>  else
>>>>>  # Dummy target needed, because used as prerequisite
>>>>>  include/config/auto.conf: ;
>>>>> @@ -786,6 +795,7 @@ ifneq ($(CONFIG_SPL_TARGET),)
>>>>>  ALL-$(CONFIG_SPL) += $(CONFIG_SPL_TARGET:"%"=%)
>>>>>  endif
>>>>>  ALL-$(CONFIG_REMAKE_ELF) += u-boot.elf
>>>>> +ALL-$(CONFIG_ARCH_BMIPS) += u-boot-bmips.elf
>>>>>  ALL-$(CONFIG_EFI_APP) += u-boot-app.efi
>>>>>  ALL-$(CONFIG_EFI_STUB) += u-boot-payload.efi
>>>>>  
>>>>> @@ -1192,6 +1202,15 @@ u-boot.elf: u-boot.bin
>>>>>  		--defsym=_start=$(CONFIG_SYS_TEXT_BASE) \
>>>>>  		-Ttext=$(CONFIG_SYS_TEXT_BASE)
>>>>>  
>>>>> +# Rules to link u-boot-bmips
>>>>> +quiet_cmd_u-boot-bmips ?= LD      $@
>>>>> +	cmd_u-boot-bmips ?= $(LD) -e startup -T u-boot-elf.lds \
>>>>> +	-Ttext $(CONFIG_SYS_TEXT_BASE) -o $@ u-boot-bmips.o
>>>>> +
>>>>> +u-boot-bmips.elf: u-boot.bin u-boot-elf.lds
>>>>> +	$(Q)$(LD) -r -b binary --oformat elf32-tradbigmips -o u-boot-bmips.o $<
>>>>> +	$(call if_changed,u-boot-bmips)
>>>>
>>>> could you try to generate the ELF binary like in the existing rule
>>>> above? If that works, we could refactor the generic rule to remove the
>>>> hard-coded aarch64 flags. If not, move this code and the
>>>> "ALL-$(CONFIG_ARCH_BMIPS) += u-boot-bmips.elf" to arch/mips/Makefile
>>> Sure, I will try and see if it works.
>> It works, but it has to be changed:
>> u-boot.elf: u-boot.bin
>> 	@$(OBJCOPY) -B mips -I binary -O elf32-tradbigmips \
>> 		$< u-boot-elf.o
>> 	@$(LD) u-boot-elf.o -o $@ \
>> 		--defsym=__start=$(CONFIG_SYS_TEXT_BASE) \
>> 		-Ttext=$(CONFIG_SYS_TEXT_BASE)
>> Changes:
>> 1) __start symbol instead of _start
>> 2) mips instead of aarch64
>> 3) elf32-tradbigmips instead of elf64-littleaarch64
> 
> 2) and 3) are expected, that's what could be fixed with a small
> refactoring. But why --defsym=__start? The U-Boot entry point is _start.
--defsym=_start throws the following error:
mips-openwrt-linux-ld.bfd: warning: cannot find entry symbol __start; defaulting to 0000000080010000
However, --defsym=__start throws no errors...

> 
>>
>>>
>>>>
>>>> Also don't forget to add new binaries to .gitignore and the Makefile
>>>> clean targets.
>>> Right, my fault :).
>>>
>>>>
>>>>> +
>>>>>  # Rule to link u-boot
>>>>>  # May be overridden by arch/$(ARCH)/config.mk
>>>>>  quiet_cmd_u-boot__ ?= LD      $@
>>>>> @@ -1340,6 +1359,9 @@ cmd_cpp_lds = $(CPP) -Wp,-MD,$(depfile) $(cpp_flags) $(LDPPFLAGS) \
>>>>>  u-boot.lds: $(LDSCRIPT) prepare FORCE
>>>>>  	$(call if_changed_dep,cpp_lds)
>>>>>  
>>>>> +u-boot-elf.lds: $(LDSCRIPT_ELF) prepare
>>>>> +	$(call if_changed_dep,cpp_lds)
>>>>> +
>>>>>  spl/u-boot-spl.bin: spl/u-boot-spl
>>>>>  	@:
>>>>>  spl/u-boot-spl: tools prepare \
>>>>> diff --git a/arch/mips/cpu/u-boot-elf.lds b/arch/mips/cpu/u-boot-elf.lds
>>>>> new file mode 100644
>>>>> index 0000000..db0bb46
>>>>> --- /dev/null
>>>>> +++ b/arch/mips/cpu/u-boot-elf.lds
>>>>> @@ -0,0 +1,10 @@
>>>>> +OUTPUT_ARCH(mips)
>>>>> +SECTIONS {
>>>>> +	.text : {
>>>>> +		startup = .;
>>>>> +		*(.text)
>>>>> +		*(.text.*)
>>>>> +		*(.data)
>>>>> +		*(.data.*)
>>>>> +	}
>>>>> +}
>>>>>
>>>>
>