（二）BSP编写（串口、MTD、UBIFS）

二、Linux3.2.8内核部分

实验5：BSP编写第一步 能挂载UBIFS的最小BSP

本次试验主要是添加JASON6410板的BSP，另外添加了NAND flash驱动，MTD及UBIFS的内核支持。

以下是mach-jason6410.c的源码：

/* linux/arch/arm/mach-s3c64xx/mach-jason6410.c
 *
 * Copyright 2012 Jason Lu <[e-mail]>
 *     http://jason2012.blog.chinaunix.net
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
*/

#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/fb.h>
#include <linux/gpio.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/dm9000.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/partitions.h>
#include <linux/serial_core.h>
#include <linux/types.h>

#include <asm/mach-types.h>
#include <asm/mach/arch.h>
#include <asm/mach/map.h>

#include <mach/map.h>
#include <mach/regs-gpio.h>
#include <mach/regs-modem.h>
#include <mach/regs-srom.h>

#include <plat/s3c6410.h>
#include <plat/adc.h>
#include <plat/cpu.h>
#include <plat/devs.h>
#include <plat/fb.h>
#include <plat/nand.h>
#include <plat/regs-serial.h>
#include <plat/ts.h>
#include <plat/regs-fb-v4.h>

#include <video/platform_lcd.h>

#define UCON S3C2410_UCON_DEFAULT
#define ULCON (S3C2410_LCON_CS8 | S3C2410_LCON_PNONE | S3C2410_LCON_STOPB)
#define UFCON (S3C2410_UFCON_RXTRIG8 | S3C2410_UFCON_FIFOMODE)

static struct s3c2410_uartcfg jason6410_uartcfgs[] __initdata = {
    [0] = {
        .hwport    = 0,
        .flags    = 0,
        .ucon    = UCON,
        .ulcon    = ULCON,
        .ufcon    = UFCON,
    },
    [1] = {
        .hwport    = 1,
        .flags    = 0,
        .ucon    = UCON,
        .ulcon    = ULCON,
        .ufcon    = UFCON,
    },
    [2] = {
        .hwport    = 2,
        .flags    = 0,
        .ucon    = UCON,
        .ulcon    = ULCON,
        .ufcon    = UFCON,
    },
    [3] = {
        .hwport    = 3,
        .flags    = 0,
        .ucon    = UCON,
        .ulcon    = ULCON,
        .ufcon    = UFCON,
    },
};

/* Nand flash */
static struct mtd_partition jason6410_nand_part[] = {
    {
        .name        = "u-boot-2011.06",
        .offset        = 0,
        .size        = (4 * 128 *SZ_1K),
        .mask_flags    = MTD_CAP_NANDFLASH,
    },
    {
        .name        = "Linux Kernel 3.2.8",
        .offset        = MTDPART_OFS_APPEND,
        .size        = (5*SZ_1M) ,
        .mask_flags    = MTD_CAP_NANDFLASH,
    },
    {
        .name        = "UBI File System",
        .offset        = MTDPART_OFS_APPEND,
        .size        = MTDPART_SIZ_FULL,
    }
};

static struct s3c2410_nand_set jason6410_nand_sets[] = {
    [0] = {
        .name        = "nand",
        .nr_chips    = 1,
        .nr_partitions    = ARRAY_SIZE(jason6410_nand_part),
        .partitions    = jason6410_nand_part,
    },
};

static struct s3c2410_platform_nand jason6410_nand_info = {
    .tacls        = 25,
    .twrph0        = 55,
    .twrph1        = 40,
    .nr_sets    = ARRAY_SIZE(jason6410_nand_sets),
    .sets        = jason6410_nand_sets,
};

static struct platform_device *jason6410_devices[] __initdata = {
    &s3c_device_nand,
};

static void __init jason6410_map_io(void)
{
    s3c64xx_init_io(NULL, 0);
    s3c24xx_init_clocks(12000000);
    s3c24xx_init_uarts(jason6410_uartcfgs, ARRAY_SIZE(jason6410_uartcfgs));
}

static void __init jason6410_machine_init(void)
{
    s3c_device_nand.name = "s3c6410-nand";
    s3c_nand_set_platdata(&jason6410_nand_info);

    platform_add_devices(jason6410_devices, ARRAY_SIZE(jason6410_devices));
}

MACHINE_START(JASON6410, "JASON6410")
    /* Maintainer: Darius Augulis <[e-mail]> */
    .atag_offset    = 0x100,
    .init_irq    = s3c6410_init_irq,
    .map_io        = jason6410_map_io,
    .init_machine    = jason6410_machine_init,
    .timer        = &s3c24xx_timer,
MACHINE_END

添加BSP支持的过程如下：

1. arch/arm/mach-s3c6410/Kconfig
line 93, add:
config MACH_JASON6410
    bool "JASON6410"
    select CPU_S3C6410
    select S3C_DEV_FB
    select S3C64XX_SETUP_FB_24BPP
    help
      Machine support for the JASON6410

2. arch/arm/mach-s3c6410/Makefile
line 47, add:
obj-$(CONFIG_MACH_JASON6410)    += mach-jason6410.o

3. 添加mach-jason6410.c到目录：arch/arm/mach-s3c6410/

另外，作为自己移植的板子，把MACHINE ID也给改了（当然，在u-boot里的也应做相应修改）。 

@arch/arm/tools/mach-types
last line, add:
jason6410        MACH_JASON6410        JASON6410        8888

这里只写出本次主要修改，其余修改过程详见《基于Tiny6410的Linux3.2.8系统移植（一）》

到此，就能正常挂载文件系统了。接下来要做的就是完善BSP并移植驱动程序。

本次试验内核配置、与标准内核的DIFF文件和内核移植过程的三个文档：

 step2.1_my_BSP_jason6410.zip