nds32: Build infrastructure

This patch adds Makefile, Kconfig and vmlinux.lds.S files required for building
an nds32 kernel.

Signed-off-by: Vincent Chen <vincentc@andestech.com>
Signed-off-by: Greentime Hu <greentime@andestech.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 174 insertions, 0 deletions

diff --git a/arch/nds32/Kconfig.cpu b/arch/nds32/Kconfig.cpu
new file mode 100644
index 000000000000..ba44cc539da9
--- /dev/null
+++ b/arch/nds32/Kconfig.cpu
@@ -0,0 +1,174 @@
+comment "Processor Features"
+
+config CPU_BIG_ENDIAN
+	bool "Big endian"
+
+config CPU_LITTLE_ENDIAN
+        def_bool !CPU_BIG_ENDIAN
+
+config HWZOL
+	bool "hardware zero overhead loop support"
+	depends on CPU_D10 || CPU_D15
+	default n
+	help
+	  A set of Zero-Overhead Loop mechanism is provided to reduce the
+	  instruction fetch and execution overhead of loop-control instructions.
+	  It will save 3 registers($LB, $LC, $LE) for context saving if say Y.
+	  You don't need to save these registers if you can make sure your user
+	  program doesn't use these registers.
+
+	  If unsure, say N.
+
+config CPU_CACHE_ALIASING
+	bool "Aliasing cache"
+	depends on CPU_N10 || CPU_D10 || CPU_N13 || CPU_V3
+	default y
+	help
+	  If this CPU is using VIPT data cache and its cache way size is larger
+	  than page size, say Y. If it is using PIPT data cache, say N.
+
+	  If unsure, say Y.
+
+choice
+	prompt "minimum CPU type"
+	default CPU_V3
+	help
+	  The data cache of N15/D15 is implemented as PIPT and it will not cause
+	  the cache aliasing issue. The rest cpus(N13, N10 and D10) are
+	  implemented as VIPT data cache. It may cause the cache aliasing issue
+	  if its cache way size is larger than page size. You can specify the
+	  CPU type direcly or choose CPU_V3 if unsure.
+
+          A kernel built for N10 is able to run on N15, D15, N13, N10 or D10.
+          A kernel built for N15 is able to run on N15 or D15.
+          A kernel built for D10 is able to run on D10 or D15.
+          A kernel built for D15 is able to run on D15.
+          A kernel built for N13 is able to run on N15, N13 or D15.
+
+config CPU_N15
+	bool "AndesCore N15"
+config CPU_N13
+	bool "AndesCore N13"
+	select CPU_CACHE_ALIASING if ANDES_PAGE_SIZE_4KB
+config CPU_N10
+	bool "AndesCore N10"
+	select CPU_CACHE_ALIASING
+config CPU_D15
+	bool "AndesCore D15"
+config CPU_D10
+	bool "AndesCore D10"
+	select CPU_CACHE_ALIASING
+config CPU_V3
+	bool "AndesCore v3 compatible"
+	select CPU_CACHE_ALIASING
+endchoice
+choice
+	prompt "Paging -- page size "
+	default ANDES_PAGE_SIZE_4KB
+config  ANDES_PAGE_SIZE_4KB
+	bool "use 4KB page size"
+config  ANDES_PAGE_SIZE_8KB
+	bool "use 8KB page size"
+endchoice
+
+config CPU_ICACHE_DISABLE
+	bool "Disable I-Cache"
+	help
+	  Say Y here to disable the processor instruction cache. Unless
+	  you have a reason not to or are unsure, say N.
+
+config CPU_DCACHE_DISABLE
+	bool "Disable D-Cache"
+	help
+	  Say Y here to disable the processor data cache. Unless
+	  you have a reason not to or are unsure, say N.
+
+config CPU_DCACHE_WRITETHROUGH
+	bool "Force write through D-cache"
+	depends on !CPU_DCACHE_DISABLE
+	help
+	  Say Y here to use the data cache in writethrough mode. Unless you
+	  specifically require this or are unsure, say N.
+
+config WBNA
+	bool "WBNA"
+	default n
+	help
+	  Say Y here to enable write-back memory with no-write-allocation policy.
+
+config ALIGNMENT_TRAP
+	bool "Kernel support unaligned access handling by sw"
+	depends on PROC_FS
+	default n
+	help
+	  Andes processors cannot load/store information which is not
+	  naturally aligned on the bus, i.e., a 4 byte load must start at an
+	  address divisible by 4. On 32-bit Andes processors, these non-aligned
+	  load/store instructions will be emulated in software if you say Y
+	  here, which has a severe performance impact. With an IP-only
+	  configuration it is safe to say N, otherwise say Y.
+
+config HW_SUPPORT_UNALIGNMENT_ACCESS
+	bool "Kernel support unaligned access handling by hw"
+	depends on !ALIGNMENT_TRAP
+	default n
+	help
+	  Andes processors load/store world/half-word instructions can access
+	  unaligned memory locations without generating the Data Alignment
+	  Check exceptions. With an IP-only configuration it is safe to say N,
+	  otherwise say Y.
+
+config HIGHMEM
+	bool "High Memory Support"
+	depends on MMU && !CPU_CACHE_ALIASING
+	help
+	  The address space of Andes processors is only 4 Gigabytes large
+	  and it has to accommodate user address space, kernel address
+	  space as well as some memory mapped IO. That means that, if you
+	  have a large amount of physical memory and/or IO, not all of the
+	  memory can be "permanently mapped" by the kernel. The physical
+	  memory that is not permanently mapped is called "high memory".
+
+	  Depending on the selected kernel/user memory split, minimum
+	  vmalloc space and actual amount of RAM, you may not need this
+	  option which should result in a slightly faster kernel.
+
+	  If unsure, say N.
+
+config CACHE_L2
+	bool "Support L2 cache"
+        default y
+	help
+	  Say Y here to enable L2 cache if your SoC are integrated with L2CC.
+	  If unsure, say N.
+
+menu "Memory configuration"
+
+choice
+	prompt "Memory split"
+	depends on MMU
+	default VMSPLIT_3G_OPT
+	help
+	  Select the desired split between kernel and user memory.
+
+	  If you are not absolutely sure what you are doing, leave this
+	  option alone!
+
+	config VMSPLIT_3G
+		bool "3G/1G user/kernel split"
+	config VMSPLIT_3G_OPT
+		bool "3G/1G user/kernel split (for full 1G low memory)"
+	config VMSPLIT_2G
+		bool "2G/2G user/kernel split"
+	config VMSPLIT_1G
+		bool "1G/3G user/kernel split"
+endchoice
+
+config PAGE_OFFSET
+	hex
+	default 0x40000000 if VMSPLIT_1G
+	default 0x80000000 if VMSPLIT_2G
+	default 0xB0000000 if VMSPLIT_3G_OPT
+	default 0xC0000000
+
+endmenu