宿主机环境：
Linux version 2.6.32-24, Ubuntu10.04
gcc version 4.1.3, Thread model: posix;
GNU Make 3.81
arm-linux-gcc 3.4.5

开发板环境：
CPU: S3C2410X
SDRAM: HY57V561620(32MB)
FLASH: K9F1208(64MB)
Linux Kernel: 2.6.23.8

移植步骤：
运行kernel的时候，我们会发现如下的错误：

JFFS2 version 2.2. (NAND) .. 2001-2006 Red Hat, Inc.
io scheduler noop registered
io scheduler anticipatory registered (default)
io scheduler deadline registered
io scheduler cfq registered
s3c2410-lcd s3c2410-lcd: no platform data for lcd, cannot attach
s3c2410-lcd: probe of s3c2410-lcd failed with error -22
lp: driver loaded but no devices found
ppdev: user-space parallel port driver
Serial: 8250/16550 driver $Revision: 1.90 $ 4 ports, IRQ sharing enabled
s3c2410-uart.0: s3c2410_serial0 at MMIO 0×50000000 (irq = 70) is a S3C2410
s3c2410-uart.1: s3c2410_serial1 at MMIO 0×50004000 (irq = 73) is a S3C2410
s3c2410-uart.2: s3c2410_serial2 at MMIO 0×50008000 (irq = 76) is a S3C2410
RAMDISK driver initialized: 16 RAM disks of 4096K size 1024 blocksize

表示与LCD相关的平台信息没有找到，因此没法加载LCD。 我们所要做的就是将对LCD设备的初始化加入到整个S3C2410的初始化过程中。

通过对arch/arm/mach-smdk2410/mach-smdk2410.c与arch/arm/mach-smdk2440/mach-smdk2440.c进行对比后，可以发现在smdk2440上存在着对结构体s3c2410fb_mach_info的初始化，而smdk2410则不存在，所以我们所要做的是把smdk2440上的初始化操作复制到smdk2410上，并做一定的修改。

rookiesean@rookiesean-desktop:~/workspace/linux-2.6.23.8$ vim arch/arm/mach-s3c2410/mach-smdk2410.c

#include <asm/plat-s3c24xx/common-smdk.h>

#include <asm/arch/smdk2410.h> // sean chi 18Aug2010, added.
#include <asm/arch/fb.h> // sean chi 31Aug2010, added.

static struct map_desc smdk2410_iodesc[] __initdata = {
{ vSMDK2410_ETH_IO , pSMDK2410_ETH_IO, SZ_1M, MT_DEVICE }, // sean chi 18Aug2010, added.
/* nothing here yet */
};

// sean chi 31Aug2010, added.
static struct s3c2410fb_mach_info nano2410_fb_info __initdata = {
.fixed_syncs = 1,
.type = S3C2410_LCDCON1_TFT,
.width        = 240,
.height        = 320,
.xres        = {
.min    = 240,
.max    = 240,
.defval    = 240,
},

.yres        = {
.min    = 320,
.max    = 320,
.defval = 320,
},

.bpp        = {
.min    = 16,
.max    = 16,
.defval = 16,
},
.regs    = {

.lcdcon1    = S3C2410_LCDCON1_TFT16BPP |
S3C2410_LCDCON1_TFT |
S3C2410_LCDCON1_CLKVAL(0×04),

.lcdcon2    = S3C2410_LCDCON2_VBPD(1) |
S3C2410_LCDCON2_LINEVAL(319) |
S3C2410_LCDCON2_VFPD(5) |
S3C2410_LCDCON2_VSPW(1),

.lcdcon3    = S3C2410_LCDCON3_HBPD(36) |
S3C2410_LCDCON3_HOZVAL(239) |
S3C2410_LCDCON3_HFPD(19),

.lcdcon4    = S3C2410_LCDCON4_MVAL(13) |
S3C2410_LCDCON4_HSPW(5),

.lcdcon5    = S3C2410_LCDCON5_FRM565 |
S3C2410_LCDCON5_INVVLINE|
S3C2410_LCDCON5_INVVFRAME|
S3C2410_LCDCON5_PWREN|
S3C2410_LCDCON5_HWSWP,
},
#if 1
.gpccon            =0xaaaaaaaa,
.gpccon_mask    =0xffffffff,
.gpcup            =0xffffffff,
.gpcup_mask        =0xffffffff,

.gpdcon            =0xaaaaaaaa,
.gpdcon_mask    =0xffffffff,
.gpdup            =0xffffffff,
.gpdup_mask        =0xffffffff,

#endif
.lpcsel        = 0×01,
};

……

…….

static void __init smdk2410_init(void)
{
s3c24xx_fb_set_platdata(&nano2410_fb_info); // sean chi 31Aug2010, added.
platform_add_devices(smdk2410_devices, ARRAY_SIZE(smdk2410_devices));
smdk_machine_init();
}

在对源代码进行修改了以后，配置内核，将Device Driver->Graphic support下的Support for frame buffer devices， S3C2410 LCD framebuffer support和Bootup logo勾选上。

rookiesean@rookiesean-desktop:~/workspace/linux-2.6.23.8$ make menuconfig

Device Driver –>

Graphics support ->

<*>Support for frame buffer devices

<*>S3C2410 LCD framebuffer support

<*>Bootup logo

对于其他版本来说，在这里可以重新编译内核，加载到开发板上运行就可以了，但在linux kernel 2.6.23上，这还不够，这时候如果编译加载的话，会在开发板上显示如下结果：

io scheduler noop registered
io scheduler anticipatory registered (default)
io scheduler deadline registered
io scheduler cfq registered
Unable to handle kernel NULL pointer dereference at virtual address 00000014
pgd = c0004000
[00000014] *pgd=00000000
Internal error: Oops: 805 [#1]
Modules linked in:
CPU: 0 Not tainted (2.6.23.8 #18)
PC is at s3c2410fb_set_lcdaddr+0×94/0xb4
LR is at 0xc02fdb48
pc : [] lr : [] psr: 60000013
sp : c03ebe24 ip : c02fdb48 fp : c03ebe40
r10: c02fc714 r9 : c0333d60 r8 : c02fc70c
r7 : c0305358 r6 : 19e80000 r5 : 19e92c00 r4 : 000000f0
r3 : 00000014 r2 : 00000001 r1 : 00000001 r0 : 00000025
Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment kernel
Control: c000717f Table: 30004000 DAC: 00000017
Process swapper (pid: 1, stack limit = 0xc03ea258)
Stack: (0xc03ebe24 to 0xc03ec000)
be20: c3c4025c c4a00000 c0305358 c0333d60 c03ebe60 c03ebe44 c014f03c
be40: c014e500 00000000 c3c4025c c3c40000 00000000 c03ebe9c c03ebe64 c001afa0
be60: c014ef7c c3c4025c c3c400a8 00000020 c03dd454 c02fc714 00000000 c03052c8
be80: c03052c8 c0337038 c0024860 00000000 c03ebeac c03ebea0 c0179df0 c001aad4
bea0: c03ebed0 c03ebeb0 c0177f30 c0179de0 c02fc7d4 c02fc714 c0178090 c03052c8
bec0: c03ea000 c03ebee8 c03ebed4 c0178110 c0177e58 00000000 c03ebeec c03ebf14
bee0: c03ebeec c0176f44 c01780a0 c0309250 c0309250 c02fc75c 00000000 c03052c8
bf00: c03052d0 c0309164 c03ebf24 c03ebf18 c0178190 c0176f04 c03ebf4c c03ebf28
bf20: c017770c c0178180 c03052c8 00000000 00000000 c0023410 c03ea000 00000000
bf40: c03ebf60 c03ebf50 c017860c c01776a8 00000000 c03ebf70 c03ebf64 c0179f04
bf60: c017859c c03ebf80 c03ebf74 c014f284 c0179ea8 c03ebff4 c03ebf84 c0008c3c
bf80: c014f280 e1a00007 e89da9f0 00000000 00000001 e24cb004 00000000 00000000
bfa0: 00000000 c03ebfb0 c002cec4 c0044b38 00000000 00000000 c0008b5c c004aee8
bfc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
bfe0: 00000000 00000000 00000000 c03ebff8 c004aee8 c0008b6c 1580302c e5943018
Backtrace:
[] (s3c2410fb_set_lcdaddr+0×0/0xb4) from [] (s3c2410fb_init_registers+0xd0/0×144)
r7:c0333d60 r6:c0305358 r5:c4a00000 r4:c3c4025c
[] (s3c2410fb_init_registers+0×0/0×144) from [] (s3c2410fb_probe+0x4dc/0x5e8)
r7:00000000 r6:c3c40000 r5:c3c4025c r4:00000000
[] (s3c2410fb_probe+0×0/0x5e8) from [] (platform_drv_probe+0×20/0×24)
[] (platform_drv_probe+0×0/0×24) from [] (driver_probe_device+0xe8/0x18c)
[] (driver_probe_device+0×0/0x18c) from [] (__driver_attach+0×80/0xe0)
r8:c03ea000 r7:c03052c8 r6:c0178090 r5:c02fc714 r4:c02fc7d4
[] (__driver_attach+0×0/0xe0) from [] (bus_for_each_dev+0×50/0×84)
r5:c03ebeec r4:00000000
[] (bus_for_each_dev+0×0/0×84) from [] (driver_attach+0×20/0×28)
r7:c0309164 r6:c03052d0 r5:c03052c8 r4:00000000
[] (driver_attach+0×0/0×28) from [] (bus_add_driver+0×74/0x1b0)
[] (bus_add_driver+0×0/0x1b0) from [] (driver_register+0×80/0×88)
[] (driver_register+0×0/0×88) from [] (platform_driver_register+0x6c/0×88)
r4:00000000
[] (platform_driver_register+0×0/0×88) from [] (s3c2410fb_init+0×14/0x1c)
[] (s3c2410fb_init+0×0/0x1c) from [] (kernel_init+0xe0/0x29c)
[] (kernel_init+0×0/0x29c) from [] (do_exit+0×0/0×748)
Code: e3530000 e1a01004 1bfbec4f e3a03014 (e4836004)
Kernel panic – not syncing: Attempted to kill init!

通过上面错误信息中的Backtrace，可以看到问题出在一个名为s3c2410fb_lcd_setaddr的函数上。在源代码中找到这个函数，存在于drivers/video/s3c2410fb.c文件里，通过对Linux 2.6.22, 2.6.23, 2.6.24的对比，发现对这段函数做如下代码修改即可，原因末知，发了邮件给写这部分代码的Ben Dooks大神询问，末回。。。

static void s3c2410fb_set_lcdaddr(struct s3c2410fb_info *fbi)
{
struct fb_var_screeninfo *var = &fbi->fb->var;
void __iomem *regs = fbi->io; // sean chi 31Aug2010, added.
unsigned long saddr1, saddr2, saddr3;

saddr1 = fbi->fb->fix.smem_start >> 1;
saddr2 = fbi->fb->fix.smem_start;
saddr2 += (var->xres * var->yres * var->bits_per_pixel)/8;
saddr2>>= 1;

saddr3 = S3C2410_OFFSIZE(0) | S3C2410_PAGEWIDTH((var->xres * var->bits_per_pixel / 16) & 0x3ff);

dprintk(“LCDSADDR1 = 0x%08lx\n”, saddr1);
dprintk(“LCDSADDR2 = 0x%08lx\n”, saddr2);
dprintk(“LCDSADDR3 = 0x%08lx\n”, saddr3);

writel(saddr1, regs + S3C2410_LCDSADDR1); // sean chi 31Aug2010, was writel(saddr, S3C2410_LCDSADDR1);
writel(saddr2, regs + S3C2410_LCDSADDR2);
writel(saddr3, regs + S3C2410_LCDSADDR3);
}

除此之外，还要把drivers/video/fbmem.c中的register_framebuffer做如下修改：

/**
* register_framebuffer – registers a frame buffer device
* @fb_info: frame buffer info structure
*
* Registers a frame buffer device @fb_info.
*
* Returns negative errno on error, or zero for success.
*
*/

int
register_framebuffer(struct fb_info *fb_info)
{
int i;
struct fb_event event;
struct fb_videomode mode;

if (num_registered_fb == FB_MAX)
return -ENXIO;
num_registered_fb++;
for (i = 0 ; i < FB_MAX; i++) if (!registered_fb[i]) break; fb_info->node = i;

fb_info->dev = device_create(fb_class, fb_info->device,
MKDEV(FB_MAJOR, i), “fb%d”, i);
if (IS_ERR(fb_info->dev)) {
/* Not fatal */
printk(KERN_WARNING “Unable to create device for framebuffer %d; errno = %ld\n”, i, PTR_ERR(fb_info->dev));
fb_info->dev = NULL;
} else
fb_init_device(fb_info);

if (fb_info->pixmap.addr == NULL) {
fb_info->pixmap.addr = kmalloc(FBPIXMAPSIZE, GFP_KERNEL);
if (fb_info->pixmap.addr) {
fb_info->pixmap.size = FBPIXMAPSIZE;
fb_info->pixmap.buf_align = 1;
fb_info->pixmap.scan_align = 1;
fb_info->pixmap.access_align = 32;
fb_info->pixmap.flags = FB_PIXMAP_DEFAULT;
}
}
fb_info->pixmap.offset = 0;

if (!fb_info->pixmap.blit_x)
fb_info->pixmap.blit_x = ~(u32)0;

if (!fb_info->pixmap.blit_y)
fb_info->pixmap.blit_y = ~(u32)0;

if (!fb_info->modelist.prev || !fb_info->modelist.next)
INIT_LIST_HEAD(&fb_info->modelist);

fb_var_to_videomode(&mode, &fb_info->var);
fb_add_videomode(&mode, &fb_info->modelist);
registered_fb[i] = fb_info;

event.info = fb_info;
// sean chi 31Aug2010, removed. fb_notifier_call_chain(FB_EVENT_FB_REGISTERED, &event);

return 0;
}

否则将会出现kernel的启动过程hang掉的情况，至于为什么这么改的原因。。。我也不知道，同样问了Ben Dooks大神，没回。。。

对Linux2.6.23进行这样的修改将会导致启动后LCD屏上不会显示LOGO， 原因在于Linux启动时LOGO的加载是由fb_notifier_call_chain调用的，但由于我们之前把fb_notifier_call_chain从启动过程中去掉了，因此我们不会看到LOGO，但通过编写应用程序对/dev/fb0进行读写依然可以在LCD屏上画出图像。