nios2: Build infrastructure

This patch adds Makefile and Kconfig files required for building a
nios2 kernel.

Signed-off-by: Ley Foon Tan <lftan@altera.com>

2 files changed, 130 insertions, 0 deletions

diff --git a/arch/nios2/platform/Kconfig.platform b/arch/nios2/platform/Kconfig.platform
new file mode 100644
index 000000000000..d3e5df9fb36b
--- /dev/null
+++ b/arch/nios2/platform/Kconfig.platform
@@ -0,0 +1,129 @@
+menu "Platform options"
+
+comment "Memory settings"
+
+config NIOS2_MEM_BASE
+	hex "Memory base address"
+	default "0x00000000"
+	help
+	  This is the physical address of the memory that the kernel will run
+	  from. This address is used to link the kernel and setup initial memory
+	  management. You should take the raw memory address without any MMU
+	  or cache bits set.
+	  Please not that this address is used directly so you have to manually
+	  do address translation if it's connected to a bridge.
+
+comment "Device tree"
+
+config NIOS2_DTB_AT_PHYS_ADDR
+	bool "DTB at physical address"
+	default n
+	help
+	  When enabled you can select a physical address to load the dtb from.
+	  Normally this address is passed by a bootloader such as u-boot but
+	  using this you can use a devicetree without a bootloader.
+	  This way you can store a devicetree in NOR flash or an onchip rom.
+	  Please note that this address is used directly so you have to manually
+	  do address translation if it's connected to a bridge. Also take into
+	  account that when using an MMU you'd have to ad 0xC0000000 to your
+	  address
+
+config NIOS2_DTB_PHYS_ADDR
+	hex "DTB Address"
+	depends on NIOS2_DTB_AT_PHYS_ADDR
+	default "0xC0000000"
+	help
+	  Physical address of a dtb blob.
+
+config NIOS2_DTB_SOURCE_BOOL
+	bool "Compile and link device tree into kernel image"
+	default n
+	help
+	  This allows you to specify a dts (device tree source) file
+	  which will be compiled and linked into the kernel image.
+
+config NIOS2_DTB_SOURCE
+	string "Device tree source file"
+	depends on NIOS2_DTB_SOURCE_BOOL
+	default ""
+	help
+	  Absolute path to the device tree source (dts) file describing your
+	  system.
+
+comment "Nios II instructions"
+
+config NIOS2_HW_MUL_SUPPORT
+	bool "Enable MUL instruction"
+	default n
+	help
+	  Set to true if you configured the Nios II to include the MUL
+	  instruction.  This will enable the -mhw-mul compiler flag.
+
+config NIOS2_HW_MULX_SUPPORT
+	bool "Enable MULX instruction"
+	default n
+	help
+	  Set to true if you configured the Nios II to include the MULX
+	  instruction.  Enables the -mhw-mulx compiler flag.
+
+config NIOS2_HW_DIV_SUPPORT
+	bool "Enable DIV instruction"
+	default n
+	help
+	  Set to true if you configured the Nios II to include the DIV
+	  instruction.  Enables the -mhw-div compiler flag.
+
+config NIOS2_FPU_SUPPORT
+	bool "Custom floating point instr support"
+	default n
+	help
+	  Enables the -mcustom-fpu-cfg=60-1 compiler flag.
+
+config NIOS2_CI_SWAB_SUPPORT
+	bool "Byteswap custom instruction"
+	default n
+	help
+	  Use the byteswap (endian converter) Nios II custom instruction provided
+	  by Altera and which can be enabled in QSYS builder. This accelerates
+	  endian conversions in the kernel (e.g. ntohs).
+
+config NIOS2_CI_SWAB_NO
+	int "Byteswap custom instruction number" if NIOS2_CI_SWAB_SUPPORT
+	default 0
+	help
+	  Number of the instruction as configured in QSYS Builder.
+
+comment "Cache settings"
+
+config CUSTOM_CACHE_SETTINGS
+	bool "Custom cache settings"
+	help
+	  This option allows you to tweak the cache settings used during early
+	  boot (where the information from device tree is not yet available).
+	  There should be no reason to change these values. Linux will work
+	  perfectly fine, even if the Nios II is configured with smaller caches.
+
+	  Say N here unless you know what you are doing.
+
+config NIOS2_DCACHE_SIZE
+	hex "D-Cache size" if CUSTOM_CACHE_SETTINGS
+	range 0x200 0x10000
+	default "0x800"
+	help
+	  Maximum possible data cache size.
+
+config NIOS2_DCACHE_LINE_SIZE
+	hex "D-Cache line size" if CUSTOM_CACHE_SETTINGS
+	range 0x10 0x20
+	default "0x20"
+	help
+	  Minimum possible data cache line size.
+
+config NIOS2_ICACHE_SIZE
+	hex "I-Cache size" if CUSTOM_CACHE_SETTINGS
+	range 0x200 0x10000
+	default "0x1000"
+	help
+	  Maximum possible instruction cache size.
+
+endmenu
diff --git a/arch/nios2/platform/Makefile b/arch/nios2/platform/Makefile
new file mode 100644
index 000000000000..46364f1d9352
--- /dev/null
+++ b/arch/nios2/platform/Makefile
@@ -0,0 +1 @@
+obj-y += platform.o