Commit eed0eabd authored by Paul Burton's avatar Paul Burton Committed by Ralf Baechle
Browse files

MIPS: generic: Introduce generic DT-based board support 



Introduce a "generic" platform, which aims to be board-agnostic by
making use of device trees passed by the boot protocol defined in the
MIPS UHI (Universal Hosting Interface) specification. Provision is made
for supporting boards which use a legacy boot protocol that can't be
changed, but adding support for such boards or any others is left to
followon patches.

Right now the built kernels expect to be loaded to 0x80100000, ie. in
kseg0. This is fine for the vast majority of MIPS platforms, but
nevertheless it would be good to remove this limitation in the future by
mapping the kernel via the TLB such that it can be loaded anywhere & map
itself appropriately.

Configuration is handled by dynamically generating configs using
scripts/kconfig/merge_config.sh, somewhat similar to the way powerpc
makes use of it. This allows for variations upon the configuration, eg.
differing architecture revisions or subsets of driver support for
differing boards, to be handled without having a large number of
defconfig files.

Signed-off-by: default avatarPaul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14353/


Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
parent cf2a5e0b

arch/mips/Kbuild.platforms

+1 −0
Original line number Diff line number Diff line
@@ -11,6 +11,7 @@ platforms += cavium-octeon 
platforms += cobalt

platforms += dec

platforms += emma

platforms += generic

platforms += jazz

platforms += jz4740

platforms += lantiq

arch/mips/Kconfig

+52 −0
Original line number Diff line number Diff line
@@ -73,6 +73,57 @@ choice 
	prompt "System type"

	default SGI_IP22



config MIPS_GENERIC

	bool "Generic board-agnostic MIPS kernel"

	select BOOT_RAW

	select BUILTIN_DTB

	select CEVT_R4K

	select CLKSRC_MIPS_GIC

	select COMMON_CLK

	select CPU_MIPSR2_IRQ_VI

	select CPU_MIPSR2_IRQ_EI

	select CSRC_R4K

	select DMA_PERDEV_COHERENT

	select HW_HAS_PCI

	select IRQ_MIPS_CPU

	select LIBFDT

	select MIPS_CPU_SCACHE

	select MIPS_GIC

	select MIPS_L1_CACHE_SHIFT_7

	select NO_EXCEPT_FILL

	select PCI_DRIVERS_GENERIC

	select PINCTRL

	select SMP_UP if SMP

	select SYS_HAS_CPU_MIPS32_R1

	select SYS_HAS_CPU_MIPS32_R2

	select SYS_HAS_CPU_MIPS32_R6

	select SYS_HAS_CPU_MIPS64_R1

	select SYS_HAS_CPU_MIPS64_R2

	select SYS_HAS_CPU_MIPS64_R6

	select SYS_SUPPORTS_32BIT_KERNEL

	select SYS_SUPPORTS_64BIT_KERNEL

	select SYS_SUPPORTS_BIG_ENDIAN

	select SYS_SUPPORTS_HIGHMEM

	select SYS_SUPPORTS_LITTLE_ENDIAN

	select SYS_SUPPORTS_MICROMIPS

	select SYS_SUPPORTS_MIPS_CPS

	select SYS_SUPPORTS_MIPS16

	select SYS_SUPPORTS_MULTITHREADING

	select SYS_SUPPORTS_RELOCATABLE

	select SYS_SUPPORTS_SMARTMIPS

	select USB_EHCI_BIG_ENDIAN_DESC if BIG_ENDIAN

	select USB_EHCI_BIG_ENDIAN_MMIO if BIG_ENDIAN

	select USB_OHCI_BIG_ENDIAN_DESC if BIG_ENDIAN

	select USB_OHCI_BIG_ENDIAN_MMIO if BIG_ENDIAN

	select USB_UHCI_BIG_ENDIAN_DESC if BIG_ENDIAN

	select USB_UHCI_BIG_ENDIAN_MMIO if BIG_ENDIAN

	select USE_OF

	help

	  Select this to build a kernel which aims to support multiple boards,

	  generally using a flattened device tree passed from the bootloader

	  using the boot protocol defined in the UHI (Unified Hosting

	  Interface) specification.



config MIPS_ALCHEMY

	bool "Alchemy processor based machines"

	select ARCH_PHYS_ADDR_T_64BIT
@@ -989,6 +1040,7 @@ source "arch/mips/ath79/Kconfig" 
source "arch/mips/bcm47xx/Kconfig"

source "arch/mips/bcm63xx/Kconfig"

source "arch/mips/bmips/Kconfig"

source "arch/mips/generic/Kconfig"

source "arch/mips/jazz/Kconfig"

source "arch/mips/jz4740/Kconfig"

source "arch/mips/lantiq/Kconfig"

arch/mips/Makefile

+56 −0
Original line number Diff line number Diff line
@@ -264,6 +264,12 @@ KBUILD_CPPFLAGS += -DDATAOFFSET=$(if $(dataoffset-y),$(dataoffset-y),0) 
bootvars-y	= VMLINUX_LOAD_ADDRESS=$(load-y) \

		  VMLINUX_ENTRY_ADDRESS=$(entry-y) \

		  PLATFORM=$(platform-y)

ifdef CONFIG_32BIT

bootvars-y	+= ADDR_BITS=32

endif

ifdef CONFIG_64BIT

bootvars-y	+= ADDR_BITS=64

endif



LDFLAGS			+= -m $(ld-emul)
@@ -431,4 +437,54 @@ define archhelp 
	echo '  dtbs_install         - Install dtbs to $(INSTALL_DTBS_PATH)'

	echo

	echo '  These will be default as appropriate for a configured platform.'

	echo

	echo '  If you are targeting a system supported by generic kernels you may'

	echo '  configure the kernel for a given architecture target like so:'

	echo

	echo '  {micro32,32,64}{r1,r2,r6}{el,}_defconfig <BOARDS="list of boards">'

	echo

	echo '  Otherwise, the following default configurations are available:'

endef



generic_config_dir = $(srctree)/arch/$(ARCH)/configs/generic

generic_defconfigs :=



#

# If the user generates a generic kernel configuration without specifying a

# list of boards to include the config fragments for, default to including all

# available board config fragments.

#

ifeq ($(BOARDS),)

BOARDS = $(patsubst board-%.config,%,$(notdir $(wildcard $(generic_config_dir)/board-*.config)))

endif



#

# Generic kernel configurations which merge generic_defconfig with the

# appropriate config fragments from arch/mips/configs/generic/, resulting in

# the ability to easily configure the kernel for a given architecture,

# endianness & set of boards without duplicating the needed configuration in

# hundreds of defconfig files.

#

define gen_generic_defconfigs

$(foreach bits,$(1),$(foreach rev,$(2),$(foreach endian,$(3),

target := $(bits)$(rev)$(filter el,$(endian))_defconfig

generic_defconfigs += $$(target)

$$(target): $(generic_config_dir)/$(bits)$(rev).config

$$(target): $(generic_config_dir)/$(endian).config

)))

endef



$(eval $(call gen_generic_defconfigs,32 64,r1 r2 r6,eb el))

$(eval $(call gen_generic_defconfigs,micro32,r2,eb el))



.PHONY: $(generic_defconfigs)

$(generic_defconfigs):

	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/kconfig/merge_config.sh \

		-m -O $(objtree) $(srctree)/arch/$(ARCH)/configs/generic_defconfig $^ \

		$(foreach board,$(BOARDS),$(generic_config_dir)/board-$(board).config)

	$(Q)$(MAKE) olddefconfig



#

# Prevent generic merge_config rules attempting to merge single fragments

#

$(generic_config_dir)/%.config: ;

arch/mips/boot/Makefile

+10 −1
Original line number Diff line number Diff line
@@ -111,13 +111,22 @@ targets += vmlinux.bz2.itb 
targets += vmlinux.lzma.itb

targets += vmlinux.lzo.itb



ifeq ($(ADDR_BITS),32)

	itb_addr_cells = 1

endif

ifeq ($(ADDR_BITS),64)

	itb_addr_cells = 2

endif



quiet_cmd_cpp_its_S = ITS     $@

      cmd_cpp_its_S = $(CPP) $(cpp_flags) -P -C -o $@ $< \

		        -DKERNEL_NAME="\"Linux $(KERNELRELEASE)\"" \

			-DVMLINUX_BINARY="\"$(3)\"" \

			-DVMLINUX_COMPRESSION="\"$(2)\"" \

			-DVMLINUX_LOAD_ADDRESS=$(VMLINUX_LOAD_ADDRESS) \

			-DVMLINUX_ENTRY_ADDRESS=$(VMLINUX_ENTRY_ADDRESS)

			-DVMLINUX_ENTRY_ADDRESS=$(VMLINUX_ENTRY_ADDRESS) \

			-DADDR_BITS=$(ADDR_BITS) \

			-DADDR_CELLS=$(itb_addr_cells)



$(obj)/vmlinux.its: $(srctree)/arch/mips/$(PLATFORM)/vmlinux.its.S FORCE

	$(call if_changed_dep,cpp_its_S,none,vmlinux.bin)

arch/mips/configs/generic/32r1.config

0 → 100644
+2 −0
Original line number Diff line number Diff line 
CONFIG_CPU_MIPS32_R1=y

CONFIG_HIGHMEM=y

CRA Git | Maintained and supported by SUSTech CRA and CCSE