[PATCH] xtensa: Architecture support for Tensilica Xtensa Part 1

The attached patches provides part 1 of an architecture implementation for the
Tensilica Xtensa CPU series.
Signed-off-by: Chris Zankel <chris@zankel.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/xtensa/Kconfig

+# For a description of the syntax of this configuration file,
+# see Documentation/kbuild/config-language.txt.
+
+mainmenu "Linux/Xtensa Kernel Configuration"
+
+config FRAME_POINTER
+	bool
+	default n
+
+config XTENSA
+	bool
+	default y
+	help
+	  Xtensa processors are 32-bit RISC machines designed by Tensilica
+	  primarily for embedded systems.  These processors are both
+	  configurable and extensible.  The Linux port to the Xtensa
+	  architecture supports all processor configurations and extensions,
+	  with reasonable minimum requirements.  The Xtensa Linux project has
+	  a home page at <http://xtensa.sourceforge.net/>.
+
+config UID16
+	bool
+	default n
+
+config RWSEM_XCHGADD_ALGORITHM
+	bool
+	default y
+
+config HAVE_DEC_LOCK
+	bool
+	default y
+
+config GENERIC_HARDIRQS
+	bool
+	default y
+
+source "init/Kconfig"
+
+menu "Processor type and features"
+
+choice
+	prompt "Xtensa Processor Configuration"
+	default XTENSA_CPU_LINUX_BE
+
+config XTENSA_CPU_LINUX_BE
+	bool "linux_be"
+	---help---
+	  The linux_be processor configuration is the baseline Xtensa
+	  configurations included in this kernel and also used by
+	  binutils, gcc, and gdb. It contains no TIE, no coprocessors,
+	  and the following configuration options:
+
+	  Code Density Option                2 Misc Special Registers
+	  NSA/NSAU Instructions              128-bit Data Bus Width
+	  Processor ID                       8K, 2-way I and D Caches
+	  Zero-Overhead Loops                2 Inst Address Break Registers
+	  Big Endian                         2 Data Address Break Registers
+	  64 General-Purpose Registers       JTAG Interface and Trace Port
+	  17 Interrupts                      MMU w/ TLBs and Autorefill
+	  3 Interrupt Levels                 8 Autorefill Ways (I/D TLBs)
+	  3 Timers                           Unaligned Exceptions
+endchoice
+
+config MMU
+	bool
+	default y
+
+config XTENSA_UNALIGNED_USER
+	bool "Unaligned memory access in use space"
+	---help---
+	   The Xtensa architecture currently does not handle unaligned
+	   memory accesses in hardware but through an exception handler.
+	   Per default, unaligned memory accesses are disabled in user space.
+
+	   Say Y here to enable unaligned memory access in user space.
+
+config PREEMPT
+	bool "Preemptible Kernel"
+	---help---
+           This option reduces the latency of the kernel when reacting to
+           real-time or interactive events by allowing a low priority process to
+           be preempted even if it is in kernel mode executing a system call.
+           Unfortunately the kernel code has some race conditions if both
+           CONFIG_SMP and CONFIG_PREEMPT are enabled, so this option is
+           currently disabled if you are building an SMP kernel.
+
+           Say Y here if you are building a kernel for a desktop, embedded
+           or real-time system.  Say N if you are unsure.
+
+config MATH_EMULATION
+	bool "Math emulation"
+	help
+	Can we use information of configuration file?
+
+config HIGHMEM
+	bool "High memory support"
+
+endmenu
+
+menu "Platform options"
+
+choice
+	prompt "Xtensa System Type"
+	default XTENSA_PLATFORM_ISS
+
+config XTENSA_PLATFORM_ISS
+	bool "ISS"
+	help
+	  ISS is an acronym for Tensilica's Instruction Set Simulator.
+
+config XTENSA_PLATFORM_XT2000
+	bool "XT2000"
+	help
+	  XT2000 is the name of Tensilica's feature-rich emulation platform.
+	  This hardware is capable of running a full Linux distribution.
+
+endchoice
+
+
+config XTENSA_CALIBRATE_CCOUNT
+	bool "Auto calibration of the CPU clock rate"
+	---help---
+	  On some platforms (XT2000, for example), the CPU clock rate can
+	  vary.  The frequency can be determined, however, by measuring
+	  against a well known, fixed frequency, such as an UART oscillator.
+
+config XTENSA_CPU_CLOCK
+	int "CPU clock rate [MHz]"
+	depends on !XTENSA_CALIBRATE_CCOUNT
+	default "16"
+
+config GENERIC_CALIBRATE_DELAY
+	bool "Auto calibration of the BogoMIPS value"
+	---help---
+	  The BogoMIPS value can easily derived from the CPU frequency.
+
+config CMDLINE_BOOL
+	bool "Default bootloader kernel arguments"
+
+config CMDLINE
+	string "Initial kernel command string"
+	depends on CMDLINE_BOOL
+	default "console=ttyS0,38400 root=/dev/ram"
+	help
+	  On some architectures (EBSA110 and CATS), there is currently no way
+	  for the boot loader to pass arguments to the kernel. For these
+	  architectures, you should supply some command-line options at build
+	  time by entering them here. As a minimum, you should specify the
+	  memory size and the root device (e.g., mem=64M root=/dev/nfs).
+
+config SERIAL_CONSOLE
+	bool
+	depends on XTENSA_PLATFORM_ISS
+	default y
+
+config XTENSA_ISS_NETWORK
+	bool
+	depends on XTENSA_PLATFORM_ISS
+	default y
+
+endmenu
+
+menu "Bus options"
+
+config PCI
+	bool "PCI support" if !XTENSA_PLATFORM_ISS
+	depends on !XTENSA_PLATFORM_ISS
+	default y
+	help
+	  Find out whether you have a PCI motherboard. PCI is the name of a
+	  bus system, i.e. the way the CPU talks to the other stuff inside
+	  your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
+	  VESA. If you have PCI, say Y, otherwise N.
+
+	  The PCI-HOWTO, available from
+	  <http://www.linuxdoc.org/docs.html#howto>, contains valuable
+	  information about which PCI hardware does work under Linux and which
+	  doesn't
+
+source "drivers/pci/Kconfig"
+
+config HOTPLUG
+
+	bool "Support for hot-pluggable devices"
+	---help---
+	Say Y here if you want to plug devices into your computer while
+	the system is running, and be able to use them quickly.  In many
+	cases, the devices can likewise be unplugged at any time too.
+
+	One well known example of this is PCMCIA- or PC-cards, credit-card
+	size devices such as network cards, modems or hard drives which are
+	plugged into slots found on all modern laptop computers.  Another
+	example, used on modern desktops as well as laptops, is USB.
+
+	Enable HOTPLUG and KMOD, and build a modular kernel.  Get agent
+	software (at <http://linux-hotplug.sourceforge.net/>) and install it.
+	Then your kernel will automatically call out to a user mode "policy
+	agent" (/sbin/hotplug) to load modules and set up software needed
+	to use devices as you hotplug them.
+
+source "drivers/pcmcia/Kconfig"
+
+source "drivers/pci/hotplug/Kconfig"
+
+endmenu
+
+menu "Exectuable file formats"
+
+# only elf supported
+config KCORE_ELF
+        bool
+        depends on PROC_FS
+        default y
+        help
+          If you enabled support for /proc file system then the file
+          /proc/kcore will contain the kernel core image in ELF format. This
+          can be used in gdb:
+
+          $ cd /usr/src/linux ; gdb vmlinux /proc/kcore
+
+          This is especially useful if you have compiled the kernel with the
+          "-g" option to preserve debugging information. It is mainly used
+	  for examining kernel data structures on the live kernel.
+
+source "fs/Kconfig.binfmt"
+
+endmenu
+
+source "drivers/Kconfig"
+
+source "fs/Kconfig"
+
+menu "Xtensa initrd options"
+	depends on BLK_DEV_INITRD
+
+	config EMBEDDED_RAMDISK
+	bool "Embed root filesystem ramdisk into the kernel"
+
+config EMBEDDED_RAMDISK_IMAGE
+	string "Filename of gziped ramdisk image"
+	depends on EMBEDDED_RAMDISK
+	default "ramdisk.gz"
+	help
+	  This is the filename of the ramdisk image to be built into the
+	  kernel.  Relative pathnames are relative to arch/xtensa/boot/ramdisk/.
+	  The ramdisk image is not part of the kernel distribution; you must
+	  provide one yourself.
+endmenu
+
+source "arch/xtensa/Kconfig.debug"
+
+source "security/Kconfig"
+
+source "crypto/Kconfig"
+
+source "lib/Kconfig"
+
+

arch/xtensa/Kconfig.debug

+menu "Kernel hacking"
+
+source "lib/Kconfig.debug"
+
+endmenu
+
+

arch/xtensa/Makefile

+#
+# This file is subject to the terms and conditions of the GNU General Public
+# License.  See the file "COPYING" in the main directory of this archive
+# for more details.
+#
+# Copyright (C) 2001 - 2005  Tensilica Inc.
+#
+# This file is included by the global makefile so that you can add your own
+# architecture-specific flags and dependencies. Remember to do have actions
+# for "archclean" and "archdep" for cleaning up and making dependencies for
+# this architecture
+
+# Core configuration.
+# (Use CPU=<xtensa_config> to use another default compiler.)
+
+cpu-$(CONFIG_XTENSA_CPU_LINUX_BE)	:= linux_be
+cpu-$(CONFIG_XTENSA_CPU_LINUX_CUSTOM)	:= linux_custom
+
+CPU = $(cpu-y)
+export CPU
+
+# Platform configuration
+
+platform-y					:= common
+platform-$(CONFIG_XTENSA_PLATFORM_XT2000)	:= xt2000
+platform-$(CONFIG_XTENSA_PLATFORM_ISS)		:= iss
+
+PLATFORM = $(platform-y)
+export PLATFORM
+
+#LDFLAGS_vmlinux		:= -T$(word 1,$(LINKSCRIPT))
+AFLAGS_vmlinux.lds.o	:= -Uxtensa
+CPPFLAGS		+= -Iarch/xtensa -Iinclude/asm  -mlongcalls  -g
+AFLAGS			+= -Iarch/xtensa -Iinclude/asm
+CPP			= $(CC) -E $(CFLAGS)
+
+cflags-y	+= -Iarch/xtensa -pipe -mlongcalls
+
+
+KBUILD_DEFCONFIG := common_defconfig
+
+# ramdisk/initrd support
+# You need a compressed ramdisk image, named ramdisk.gz in
+# arch/xtensa/boot/ramdisk
+
+core-$(CONFIG_EMBEDDED_RAMDISK)	+= arch/xtensa/boot/ramdisk/
+
+# Test for cross compiling
+
+ifneq ($(CPU),)
+  COMPILE_ARCH = $(shell uname -m)
+
+  ifneq ($(COMPILE_ARCH), xtensa)
+    ifndef CROSS_COMPILE
+      CROSS_COMPILE = xtensa_$(CPU)-
+    endif
+  endif
+endif
+
+#
+
+LIBGCC := $(shell $(CC) $(CFLAGS) -print-libgcc-file-name)
+
+head-y		:= arch/xtensa/kernel/head.o
+core-y		+= arch/xtensa/kernel/ \
+		   arch/xtensa/mm/ arch/xtensa/platform-$(PLATFORM)/
+libs-y		+= arch/xtensa/lib/ $(LIBGCC)
+
+boot	:= arch/xtensa/boot
+
+arch/xtensa/kernel/asm-offsets.s: \
+	arch/xtensa/kernel/asm-offsets.c \
+	include/asm-xtensa/.platform
+
+include/asm-xtensa/offsets.h: arch/xtensa/kernel/asm-offsets.s
+	$(call filechk,gen-asm-offsets)
+
+prepare: include/asm-xtensa/.platform include/asm-xtensa/offsets.h
+
+# Update machine cpu and platform symlinks if something which affects
+# them changed.
+
+include/asm-xtensa/.platform: $(wildcard include/config/arch/*.h)
+	@echo '  Setting up cpu ($(CPU)) and platform ($(PLATFORM)) symlinks'
+	$(Q)rm -f include/asm-xtensa/platform
+	$(Q)rm -f include/asm-xtensa/xtensa/config
+	$(Q)(cd include/asm-xtensa/; ln -sf platform-$(PLATFORM) platform)
+	$(Q)(cd include/asm-xtensa/xtensa; ln -sf config-$(CPU) config)
+
+all: zImage
+
+bzImage : zImage
+
+zImage zImage.initrd: vmlinux
+	$(Q)$(MAKE) $(build)=$(boot) $@
+
+CLEAN_FILES	+= arch/xtensa/vmlinux.lds include/asm-xtensa/offset.h
+
+define archhelp
+  @echo '* zImage      - Compressed kernel image (arch/xtensa/boot/images/zImage.*)'
+endef
+