mn10300: add the MN10300/AM33 architecture to the kernel

			   =========================

			   MN10300 FUNCTION CALL ABI

			   =========================

=======

GENERAL

=======

The MN10300/AM33 kernel runs in little-endian mode; big-endian mode is not

supported.

The stack grows downwards, and should always be 32-bit aligned. There are

separate stack pointer registers for userspace and the kernel.

================

ARGUMENT PASSING

================

The first two arguments (assuming up to 32-bits per argument) to a function are

passed in the D0 and D1 registers respectively; all other arguments are passed

on the stack.

If 64-bit arguments are being passed, then they are never split between

registers and the stack. If the first argument is a 64-bit value, it will be

passed in D0:D1. If the first argument is not a 64-bit value, but the second

is, the second will be passed entirely on the stack and D1 will be unused.

Arguments smaller than 32-bits are not coelesced within a register or a stack

word. For example, two byte-sized arguments will always be passed in separate

registers or word-sized stack slots.

=================

CALLING FUNCTIONS

=================

The caller must allocate twelve bytes on the stack for the callee's use before

it inserts a CALL instruction. The CALL instruction will write into the TOS

word, but won't actually modify the stack pointer; similarly, the RET

instruction reads from the TOS word of the stack, but doesn't move the stack

pointer beyond it.

	Stack:

	|		|

	|		|

	|---------------| SP+20

	| 4th Arg	|

	|---------------| SP+16

	| 3rd Arg	|

	|---------------| SP+12

	| D1 Save Slot	|

	|---------------| SP+8

	| D0 Save Slot	|

	|---------------| SP+4

	| Return Addr	|

	|---------------| SP

	|		|

	|		|

The caller must leave space on the stack (hence an allocation of twelve bytes)

in which the callee may store the first two arguments.

============

RETURN VALUE

============

The return value is passed in D0 for an integer (or D0:D1 for a 64-bit value),

or A0 for a pointer.

If the return value is a value larger than 64-bits, or is a structure or an

array, then a hidden first argument will be passed to the callee by the caller:

this will point to a piece of memory large enough to hold the result of the

function. In this case, the callee will return the value in that piece of

memory, and no value will be returned in D0 or A0.

===================

REGISTER CLOBBERING

===================

The values in certain registers may be clobbered by the callee, and other

values must be saved:

	Clobber:	D0-D1, A0-A1, E0-E3

	Save:		D2-D3, A2-A3, E4-E7, SP

All other non-supervisor-only registers are clobberable (such as MDR, MCRL,

MCRH).

=================

SPECIAL REGISTERS

=================

Certain ordinary registers may carry special usage for the compiler:

	A3:	Frame pointer

	E2:	TLS pointer

==========

KERNEL ABI

==========

The kernel may use a slightly different ABI internally.

 (*) E2

     If CONFIG_MN10300_CURRENT_IN_E2 is defined, then the current task pointer

     will be kept in the E2 register, and that register will be marked

     unavailable for the compiler to use as a scratch register.

     Normally the kernel uses something like:

	MOV	SP,An

	AND	0xFFFFE000,An

	MOV	(An),Rm		// Rm holds current

	MOV	(yyy,Rm)	// Access current->yyy

     To find the address of current; but since this option permits current to

     be carried globally in an register, it can use:

	MOV	(yyy,E2)	// Access current->yyy

     instead.

===============

SYSTEM CALL ABI

===============

System calls are called with the following convention:

	REGISTER	ENTRY			EXIT

	===============	=======================	=======================

	D0		Syscall number		Return value

	A0		1st syscall argument	Saved

	D1		2nd syscall argument	Saved

	A3		3rd syscall argument	Saved

	A2		4th syscall argument	Saved

	D3		5th syscall argument	Saved

	D2		6th syscall argument	Saved

All other registers are saved.  The layout is a consequence of the way the MOVM

instruction stores registers onto the stack.

		   =========================================

		   PART-SPECIFIC SOURCE COMPARTMENTALISATION

		   =========================================

The sources for various parts are compartmentalised at two different levels:

 (1) Processor level

     The "processor level" is a CPU core plus the other on-silicon

     peripherals.

     Processor-specific header files are divided among directories in a similar

     way to the CPU level:

	(*) include/asm-mn10300/proc-mn103e010/

	    Support for the AM33v2 CPU core.

     The appropriate processor is selected by a CONFIG_MN10300_PROC_YYYY option

     from the "Processor support" choice menu in the arch/mn10300/Kconfig file.

 (2) Unit level

     The "unit level" is a processor plus all the external peripherals

     controlled by that processor.

     Unit-specific header files are divided among directories in a similar way

     to the CPU level; not only that, but specific sources may also be

     segregated into separate directories under the arch directory:

	(*) include/asm-mn10300/unit-asb2303/

	(*) arch/mn10300/unit-asb2303/

	    Support for the ASB2303 board with an ASB2308 daughter board.

	(*) include/asm-mn10300/unit-asb2305/

	(*) arch/mn10300/unit-asb2305/

	    Support for the ASB2305 board.

     The appropriate processor is selected by a CONFIG_MN10300_UNIT_ZZZZ option

     from the "Unit type" choice menu in the arch/mn10300/Kconfig file.

============

COMPILE TIME

============

When the kernel is compiled, symbolic links will be made in the asm header file

directory for this arch:

	include/asm-mn10300/proc => include/asm-mn10300/proc-YYYY/

	include/asm-mn10300/unit => include/asm-mn10300/unit-ZZZZ/

So that the header files contained in those directories can be accessed without

lots of #ifdef-age.

The appropriate arch/mn10300/unit-ZZZZ directory will also be entered by the

compilation process; all other unit-specific directories will be ignored.

W:	http://www.linux-mm.org

S:	Maintained

MEI MN10300/AM33 PORT

P:	David Howells

M:	dhowells@redhat.com

P:	Koichi Yasutake

M:	yasutake.koichi@jp.panasonic.com

L:	linux-am33-list@redhat.com

W:	ftp://ftp.redhat.com/pub/redhat/gnupro/AM33/

S:	Maintained

MEMORY TECHNOLOGY DEVICES (MTD)

P:	David Woodhouse

M:	dwmw2@infradead.org

#

# For a description of the syntax of this configuration file,

# see Documentation/kbuild/kconfig-language.txt.

#

mainmenu "Linux Kernel Configuration"

config MN10300

	def_bool y

config AM33

	def_bool y

config MMU

	def_bool y

config HIGHMEM

	def_bool n

config NUMA

	def_bool n

config UID16

	def_bool y

config RWSEM_GENERIC_SPINLOCK

	def_bool y

config RWSEM_XCHGADD_ALGORITHM

	bool

config GENERIC_HARDIRQS_NO__DO_IRQ

	def_bool y

config GENERIC_CALIBRATE_DELAY

	def_bool y

config GENERIC_FIND_NEXT_BIT

	def_bool y

config GENERIC_HWEIGHT

	def_bool y

config GENERIC_TIME

	def_bool y

config GENERIC_BUG

	def_bool y

config QUICKLIST

	def_bool y

config ARCH_HAS_ILOG2_U32

	def_bool y

config ARCH_SUPPORTS_AOUT

	def_bool n

# Use the generic interrupt handling code in kernel/irq/

config GENERIC_HARDIRQS

	def_bool y

config HOTPLUG_CPU

	def_bool n

mainmenu "Matsushita MN10300/AM33 Kernel Configuration"

source "init/Kconfig"

menu "Matsushita MN10300 system setup"

choice

	prompt "Unit type"

	default MN10300_UNIT_ASB2303

	help

	  This option specifies board for which the kernel will be

	  compiled. It affects the external peripherals catered for.

config MN10300_UNIT_ASB2303

	bool "ASB2303"

config MN10300_UNIT_ASB2305

	bool "ASB2305"

endchoice

choice

	prompt "Processor support"

	default MN10300_PROC_MN103E010

	help

	  This option specifies the processor for which the kernel will be

	  compiled. It affects the on-chip peripherals catered for.

config MN10300_PROC_MN103E010

	bool "MN103E010"

	depends on MN10300_UNIT_ASB2303 || MN10300_UNIT_ASB2305

	select MN10300_PROC_HAS_TTYSM0

	select MN10300_PROC_HAS_TTYSM1

	select MN10300_PROC_HAS_TTYSM2

endchoice

choice

	prompt "Processor core support"

	default MN10300_CPU_AM33V2

	help

	  This option specifies the processor core for which the kernel will be

	  compiled. It affects the instruction set used.

config MN10300_CPU_AM33V2

	bool "AM33v2"

endchoice

config FPU

	bool "FPU present"

	default y

	depends on MN10300_PROC_MN103E010

choice

	prompt "CPU Caching mode"

	default MN10300_CACHE_WBACK

	help

	  This option determines the caching mode for the kernel.

	  Write-Back caching mode involves the all reads and writes causing

	  the affected cacheline to be read into the cache first before being

	  operated upon. Memory is not then updated by a write until the cache

	  is filled and a cacheline needs to be displaced from the cache to

	  make room. Only at that point is it written back.

	  Write-Through caching only fetches cachelines from memory on a

	  read. Writes always get written directly to memory. If the affected

	  cacheline is also in cache, it will be updated too.

	  The final option is to turn of caching entirely.

config MN10300_CACHE_WBACK

	bool "Write-Back"

config MN10300_CACHE_WTHRU

	bool "Write-Through"

config MN10300_CACHE_DISABLED

	bool "Disabled"

endchoice

menu "Memory layout options"

config KERNEL_RAM_BASE_ADDRESS

	hex "Base address of kernel RAM"

	default "0x90000000"

config INTERRUPT_VECTOR_BASE

	hex "Base address of vector table"

	default "0x90000000"

	help

	  The base address of the vector table will be programmed into

          the TBR register. It must be on 16MiB address boundary.

config KERNEL_TEXT_ADDRESS

	hex "Base address of kernel"

	default "0x90001000"

config KERNEL_ZIMAGE_BASE_ADDRESS

	hex "Base address of compressed vmlinux image"

	default "0x90700000"

endmenu

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.

	  This allows applications to run more reliably even when the system is

	  under load.

	  Say Y here if you are building a kernel for a desktop, embedded

	  or real-time system.  Say N if you are unsure.

config PREEMPT_BKL

	bool "Preempt The Big Kernel Lock"

	depends on PREEMPT

	default y

	help

	  This option reduces the latency of the kernel by making the

	  big kernel lock preemptible.

	  Say Y here if you are building a kernel for a desktop system.

	  Say N if you are unsure.

config MN10300_CURRENT_IN_E2

	bool "Hold current task address in E2 register"

	default y

	help

	  This option removes the E2/R2 register from the set available to gcc

	  for normal use and instead uses it to store the address of the

	  current process's task_struct whilst in the kernel.

	  This means the kernel doesn't need to calculate the address each time

	  "current" is used (take SP, AND with mask and dereference pointer

	  just to get the address), and instead can just use E2+offset

	  addressing each time.

	  This has no effect on userspace.

config MN10300_USING_JTAG

	bool "Using JTAG to debug kernel"

	default y

	help

	  This options indicates that JTAG will be used to debug the kernel. It

	  suppresses the use of certain hardware debugging features, such as

	  single-stepping, which are taken over completely by the JTAG unit.

config MN10300_RTC

	bool "Using MN10300 RTC"

	depends on MN10300_PROC_MN103E010

	default n

	help

	  This option enables support for the RTC, thus enabling time to be

	  tracked, even when system is powered down. This is available on-chip

	  on the MN103E010.

config MN10300_WD_TIMER

	bool "Using MN10300 watchdog timer"

	default y

	help

	  This options indicates that the watchdog timer will be used.

config PCI

	bool "Use PCI"

	depends on MN10300_UNIT_ASB2305

	default y

	help

	  Some systems (such as the ASB2305) have PCI onboard. If you have one

	  of these boards and you wish to use the PCI facilities, say Y here.

	  The PCI-HOWTO, available from

	  <http://www.tldp.org/docs.html#howto>, contains valuable

	  information about which PCI hardware does work under Linux and which

	  doesn't.

source "drivers/pci/Kconfig"

source "drivers/pcmcia/Kconfig"

menu "MN10300 internal serial options"

config MN10300_PROC_HAS_TTYSM0

	bool

	default n

config MN10300_PROC_HAS_TTYSM1

	bool

	default n

config MN10300_PROC_HAS_TTYSM2

	bool

	default n

config MN10300_TTYSM

	bool "Support for ttySM serial ports"

	depends on MN10300

	default y

	select SERIAL_CORE

	help

	  This option enables support for the on-chip serial ports that the

	  MN10300 has available.

config MN10300_TTYSM_CONSOLE

	bool "Support for console on ttySM serial ports"

	depends on MN10300_TTYSM

	select SERIAL_CORE_CONSOLE

	help

	  This option enables support for a console on the on-chip serial ports

	  that the MN10300 has available.

#

# /dev/ttySM0

#

config MN10300_TTYSM0

	bool "Enable SIF0 (/dev/ttySM0)"

	depends on MN10300_TTYSM && MN10300_PROC_HAS_TTYSM0

	help

	  Enable access to SIF0 through /dev/ttySM0 or gdb-stub

choice

	prompt "Select the timer to supply the clock for SIF0"

	default MN10300_TTYSM0_TIMER8

	depends on MN10300_TTYSM0

config MN10300_TTYSM0_TIMER8

	bool "Use timer 8 (16-bit)"

config MN10300_TTYSM0_TIMER2

	bool "Use timer 2 (8-bit)"

endchoice

#

# /dev/ttySM1

#

config MN10300_TTYSM1

	bool "Enable SIF1 (/dev/ttySM1)"

	depends on MN10300_TTYSM && MN10300_PROC_HAS_TTYSM1

	help

	  Enable access to SIF1 through /dev/ttySM1 or gdb-stub

choice

	prompt "Select the timer to supply the clock for SIF1"

	default MN10300_TTYSM0_TIMER9

	depends on MN10300_TTYSM1

config MN10300_TTYSM1_TIMER9

	bool "Use timer 9 (16-bit)"

config MN10300_TTYSM1_TIMER3

	bool "Use timer 3 (8-bit)"

endchoice

#

# /dev/ttySM2

#

config MN10300_TTYSM2

	bool "Enable SIF2 (/dev/ttySM2)"

	depends on MN10300_TTYSM && MN10300_PROC_HAS_TTYSM2

	help

	  Enable access to SIF2 through /dev/ttySM2 or gdb-stub

choice

	prompt "Select the timer to supply the clock for SIF2"

	default MN10300_TTYSM0_TIMER10

	depends on MN10300_TTYSM2

config MN10300_TTYSM2_TIMER10

	bool "Use timer 10 (16-bit)"

endchoice

config MN10300_TTYSM2_CTS

	bool "Enable the use of the CTS line /dev/ttySM2"

	depends on MN10300_TTYSM2

endmenu

source "mm/Kconfig"

menu "Power management options"

source kernel/power/Kconfig

endmenu

endmenu

menu "Executable formats"

source "fs/Kconfig.binfmt"

endmenu

source "net/Kconfig"

source "drivers/Kconfig"

source "fs/Kconfig"

source "arch/mn10300/Kconfig.debug"

source "security/Kconfig"

source "crypto/Kconfig"

source "lib/Kconfig"

source "arch/mn10300/oprofile/Kconfig"

menu "Kernel hacking"

source "lib/Kconfig.debug"

config DEBUG_STACKOVERFLOW

	bool "Check for stack overflows"

	depends on DEBUG_KERNEL

config DEBUG_DECOMPRESS_KERNEL

	bool "Using serial port during decompressing kernel"

	depends on DEBUG_KERNEL

	default n

	help

	  If you say Y here you will confirm the start and the end of

	  decompressing Linux seeing "Uncompressing Linux... " and

	  "Ok, booting the kernel.\n" on console.

config KPROBES

	bool "Kprobes"

	depends on DEBUG_KERNEL

	help

	  Kprobes allows you to trap at almost any kernel address and

	  execute a callback function.  register_kprobe() establishes

	  a probepoint and specifies the callback.  Kprobes is useful

	  for kernel debugging, non-intrusive instrumentation and testing.

	  If in doubt, say "N".

config GDBSTUB

	bool "Remote GDB kernel debugging"

	depends on DEBUG_KERNEL

	select DEBUG_INFO

	select FRAME_POINTER

	help

	  If you say Y here, it will be possible to remotely debug the kernel

	  using gdb. This enlarges your kernel ELF image disk size by several

	  megabytes and requires a machine with more than 16 MB, better 32 MB

	  RAM to avoid excessive linking time. This is only useful for kernel

	  hackers. If unsure, say N.

config GDBSTUB_IMMEDIATE

	bool "Break into GDB stub immediately"

	depends on GDBSTUB

	help

	  If you say Y here, GDB stub will break into the program as soon as

	  possible, leaving the program counter at the beginning of

	  start_kernel() in init/main.c.

config GDB_CONSOLE

	bool "Console output to GDB"

	depends on GDBSTUB

	help

	  If you are using GDB for remote debugging over a serial port and

	  would like kernel messages to be formatted into GDB $O packets so

	  that GDB prints them as program output, say 'Y'.

config GDBSTUB_DEBUGGING

	bool "Debug GDB stub by messages to serial port"

	depends on GDBSTUB

	help

	  This causes debugging messages to be displayed at various points

	  during execution of the GDB stub routines. Such messages will be

	  displayed on ttyS0 if that isn't the GDB stub's port, or ttySM0

	  otherwise.

config GDBSTUB_DEBUG_ENTRY

	bool "Debug GDB stub entry"

	depends on GDBSTUB_DEBUGGING

	help

	  This option causes information to be displayed about entry to or exit

	  from the main GDB stub routine.

config GDBSTUB_DEBUG_PROTOCOL

	bool "Debug GDB stub protocol"

	depends on GDBSTUB_DEBUGGING

	help

	  This option causes information to be displayed about the GDB remote

	  protocol messages generated exchanged with GDB.

config GDBSTUB_DEBUG_IO

	bool "Debug GDB stub I/O"

	depends on GDBSTUB_DEBUGGING

	help

	  This option causes information to be displayed about GDB stub's

	  low-level I/O.

config GDBSTUB_DEBUG_BREAKPOINT

	bool "Debug GDB stub breakpoint management"

	depends on GDBSTUB_DEBUGGING

	help

	  This option causes information to be displayed about GDB stub's

	  breakpoint management.

choice

	prompt "GDB stub port"

	default GDBSTUB_TTYSM0

	depends on GDBSTUB

	help

	  Select the serial port used for GDB-stub.

config GDBSTUB_ON_TTYSM0

	bool "/dev/ttySM0 [SIF0]"

	depends on MN10300_TTYSM0

	select GDBSTUB_ON_TTYSMx

config GDBSTUB_ON_TTYSM1

	bool "/dev/ttySM1 [SIF1]"

	depends on MN10300_TTYSM1

	select GDBSTUB_ON_TTYSMx

config GDBSTUB_ON_TTYSM2

	bool "/dev/ttySM2 [SIF2]"

	depends on MN10300_TTYSM2

	select GDBSTUB_ON_TTYSMx

config GDBSTUB_ON_TTYS0

	bool "/dev/ttyS0"

	select GDBSTUB_ON_TTYSx

config GDBSTUB_ON_TTYS1

	bool "/dev/ttyS1"

	select GDBSTUB_ON_TTYSx

endchoice

config GDBSTUB_ON_TTYSMx

	bool

	depends on GDBSTUB_ON_TTYSM0 || GDBSTUB_ON_TTYSM1 || GDBSTUB_ON_TTYSM2

	default y

config GDBSTUB_ON_TTYSx

	bool

	depends on GDBSTUB_ON_TTYS0 || GDBSTUB_ON_TTYS1

	default y

endmenu