1. mach-types add one entry
# machine_is_xxx CONFIG_xxxx MACH_TYPE_xxx number
ks8695 ARCH_KS8695 KS8695 180
The above file is needed so that the cript
linux/arch/arm/tools/gen-mach-types can generate
linux/include/asm-arm/mach-types.h
2.ks8695_defconfig create a config file
When you do make _config, e.g.make ks8695_config
to build a kernel,then the file corresponding to the first part of
the parameter is copied out of linux/arch/arm/def-configs/ to
linux/.config
3.Kconfig
config ARCH_KS8695
bool "Micrel/Kendin KS8695"
help
Support for Micrel/Kendin KS8695 "Centaur" (ARM922T) based
System-on-Chip devices.
4. Kconfig
1."Processor Type"
# Select CPU types depending on the architecture selected. This
selects which CPUs we support in the kernel image, and the
compiler instruction optimiser behaviour.
# ARM922T
config CPU_ARM922T
bool "Support ARM922T processor" if ARCH_INTEGRATOR
depends on ARCH_LH7A40X || ARCH_INTEGRATOR || ARCH_KS8695
default y if ARCH_LH7A40X || ARCH_KS8695
select CPU_32v4T
select CPU_ABRT_EV4T
select CPU_CACHE_V4WT
select CPU_CACHE_VIVT
select CPU_CP15_MMU
select CPU_COPY_V4WB if MMU
select CPU_TLB_V4WBI if MMU
help
The ARM922T is a version of the ARM920T, but with smaller
instruction and data caches. It is used in Altera's
Excalibur XA device family and Micrel's KS8695 Centaur.
Say Y if you want support for the ARM922T processor.
Otherwise, say N.
2."Processor Features"
config CPU_BIG_ENDIAN
bool "Build big-endian kernel"
depends on ARCH_SUPPORTS_BIG_ENDIAN
help
Say Y if you plan on running a kernel in big-endian mode.
Note that your board must be properly built and your board
port must properly enable any big-endian related features
of your chipset/board/processor.
=================================================================
================================================================= STEP 1: make files 0.
(zreladdr-y)
(params_phys-y)
(initrd_phys-y)
1.Makefile
machine-$(CONFIG_ARCH_KS8695) := ks8695
ifneq ($(machine-y),)
MACHINE := arch/arm/mach-$(machine-y)/
2.Makefile
ifneq ($(MACHINE),)
include $(srctree)/$(MACHINE)/Makefile.boot
endif
# Note: the following conditions must always be true:
# ZRELADDR == virt_to_phys(PAGE_OFFSET + TEXT_OFFSET)
# PARAMS_PHYS must be within 4MB of ZRELADDR
# INITRD_PHYS must be in RAM
ZRELADDR := $(zreladdr-y)
PARAMS_PHYS := $(params_phys-y)
INITRD_PHYS := $(initrd_phys-y)
export ZRELADDR INITRD_PHYS PARAMS_PHYS
targets := Image zImage xipImage bootpImage uImage
================================================================= STEP 2:.C .S files 1. directory
-- Low-level IRQ helper macros
-- Debug output macros
-- Irq number definations
-- DMA definations
-- Memory mapping/translation
-- Reset operation
-- IDLE function
makefile.boot define macros zreladdr-y
entry-macro.S Low-level IRQ helper macros for machine
get_irqnr_and_base
disable_irq
debug-macro.S
these are low level debug function, which talk to a
serial port without relying on interrupts and any other
kernel functionality
Reference:
head.S
entry-header.S
entry-armv.S
entry-common.S
arch.c /*may be use other file name.: board-micrel.c*/
define structure machie_desc map_desc and map_io function
This should contain the architecture-specific fix ups and IO
MACHINE_START(KS8695, "KS8695 Centaur Development Board")
/* Maintainer: Micrel Semiconductor Inc. */
.phys_io = KS8695_IO_PA,
.io_pg_offst = (KS8695_IO_VA >> 18) & 0xfffc,
.boot_params = KS8695_SDRAM_PA + 0x100,
.map_io = ks8695_map_io,
.init_irq = ks8695_init_irq,
.init_machine = micrel_init,
.timer = &ks8695_timer,
MACHINE_END
ks8695_map_io()->iotable_init()
will be called in pageing_init/devicemaps_init in arch/mm.c
static struct __initdata map_desc ks8695_io_desc[] = {
{
.virtual = KS8695_IO_VA,
.pfn = __phys_to_pfn(KS8695_IO_PA),
.length = KS8695_IO_SIZE,
.type = MT_DEVICE,
}
};
irq.c
You should provide the XXX_init_irq function here. This sets
up the interrupt controller.Interrupt mask and unmask func-
tions
=================================================================
================================================================= STEP 3: include files
[asm-arm/arch-ks8695/]|[asm-arm/]memroy.h
PHYS_OFFSET
refer to /documents/arm/porting and documents/arm/memory.txt
kernel memory symbol defintion.
[asm-arm/mach]|[asm-arm/arch-ks8695]|[/asm-arm/]dma.h
Defines for DMA channels,and DMA-able areas of memory
[asm-arm/arch-ks8695/]|[asm-arm/]hardware.h
define the memory addresses,IO addresses,and so on,according
to your hardware specifications (memory map and IO map).
#define KS8695_SDRAM_PA 0x00000000
#define KS8695_IO_PA 0x03F00000
#define KS8695_IO_VA 0xF0000000
#define KS8695_IO_SIZE SZ_1M
#define KS8695_PCIMEM_PA 0x60000000
#define KS8695_PCIMEM_SIZE SZ_512M
#define KS8695_PCIIO_PA 0x80000000
#define KS8695_PCIIO_SIZE SZ_64K
[asm-arm/arch-ks8695/]|[asm-arm/]io.h