ARM+LINUX移植攻略（十）支持东华 3.5寸LCD输出console信息和BMP图片、logo

哈尔滨理工大学软件工程专业08-7李万鹏原创作品，转载请标明出处

http://blog.csdn.net/woshixingaaa/archive/2011/02/19/6194637.aspx

由于linux启动代码，仍然出现乱码，而我将启动信息输出到lcd就没有乱码。暂时这个问题还没有解决，lcd其实早已完成，今天整理下，再解决那个问题。

下面是我绘制的主要的lcd驱动调用流程图。start_armboot()在lib_arm/board.c中，stdio_init()在common/stdio.cdrv_video_init(),video_init(),video_logo (),video_fb_address(）在drivers/video/cfb_console.c中，video_hw_init()在drivers/video/s3c2410_fb.c中，board_video_init()在board/samsung/TE2440II/TE2440II.c。

最终调用了board_video_init()函数，这个函数由我们自己来编写，由于以前写过裸机的lcd程序，所以时序就可以直接拿来用，不用调了，哈哈。在这个函数中主要还是对那5个lcd的控制寄存器进行初始化。这里要注意根据不同的屏，进行x,y的调整，我用的是东华WXCAT35-TG3#001，主要就是初始化一个GraphicDevice *pGD结构体。

#define MVAL (0) #define MVAL_USED (0) //0=each frame 1=rate by MVAL #define INVVDEN (0) //0=normal 1=inverted #define BSWP (0) //Byte swap control #define HWSWP (0) //Half word swap control //TFT 240320 #define LCD_XSIZE_TFT_240320 (320) #define LCD_YSIZE_TFT_240320 (240) //TFT240320 #define HOZVAL_TFT_240320 (LCD_XSIZE_TFT_240320-1) #define LINEVAL_TFT_240320 (LCD_YSIZE_TFT_240320-1) //Timing parameter for WXCAT35-TG3#001" #define VBPD_240320 (3) #define VFPD_240320 (5) #define VSPW_240320 (15) #define HBPD_240320 (58) #define HFPD_240320 (15) #define HSPW_240320_WXCAT35 (8) //Adjust the horizontal displacement of the screen #define CLKVAL_TFT_240320 (7) //FCLK=405MHz,HCLK=101.25MHz,VCLK=4602272Hz void board_video_init(GraphicDevice *pGD) { S3C24X0_LCD * const lcd = S3C24X0_GetBase_LCD(); S3C2410_NAND * const nand = S3C2410_GetBase_NAND(); /* FIXME: select LCM type by env variable */ /* Configuration for GTA01 LCM on QT2410 */ lcd->LCDCON1 = 0x00000778; /* CLKVAL=7, BPPMODE=16bpp, TFT, ENVID=0 */ lcd->LCDCON2 = (VBPD_240320<<24)|(LINEVAL_TFT_240320<<14)|(VFPD_240320<<6)|(VSPW_240320); lcd->LCDCON3 = (HBPD_240320<<19)|(HOZVAL_TFT_240320<<8)|(HFPD_240320); lcd->LCDCON4 = (MVAL<<8)|(HSPW_240320_WXCAT35); lcd->LCDCON5 = 0x00000f09; lcd->LPCSEL = 0x00000000; }

明白上边的流程后一切变得很简单，只要根据自己的屏调整好时序就行了。添加一个驱动文件这个是一个外国的牛人已经写好的。在drivers/video/下添加s3c2410_fb.c。代码如下：

/* * (C) Copyright 2006 by OpenMoko, Inc. * Author: Harald Welte <laforge@openmoko.org> * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation; either version 2 of * the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, * MA 02111-1307 USA */ #include <common.h> #if defined(CONFIG_VIDEO_S3C2410) #include <video_fb.h> #include "videomodes.h" #include <s3c2410.h> /* * Export Graphic Device */ GraphicDevice smi; #define VIDEO_MEM_SIZE 0x200000 /* 240x320x16bit = 0x25800 bytes */ extern void board_video_init(GraphicDevice *pGD); /******************************************************************************* * * Init video chip with common Linux graphic modes (lilo) */ void *video_hw_init (void) { S3C24X0_LCD * const lcd = S3C24X0_GetBase_LCD(); GraphicDevice *pGD = (GraphicDevice *)&smi; int videomode; unsigned long t1, hsynch, vsynch; char *penv; int tmp, i, bits_per_pixel; struct ctfb_res_modes *res_mode; struct ctfb_res_modes var_mode; // unsigned char videoout; /* Search for video chip */ printf("Video: "); tmp = 0; videomode = CFG_SYS_DEFAULT_VIDEO_MODE; /* get video mode via environment */ if ((penv = getenv ("videomode")) != NULL) { /* deceide if it is a string */ if (penv[0] <= '9') { videomode = (int) simple_strtoul (penv, NULL, 16); tmp = 1; } } else { tmp = 1; } if (tmp) { /* parameter are vesa modes */ /* search params */ for (i = 0; i < VESA_MODES_COUNT; i++) { if (vesa_modes[i].vesanr == videomode) break; } if (i == VESA_MODES_COUNT) { printf ("no VESA Mode found, switching to mode 0x%x ", CFG_SYS_DEFAULT_VIDEO_MODE); i = 0; } res_mode = (struct ctfb_res_modes *) &res_mode_init[vesa_modes[i]. resindex]; bits_per_pixel = vesa_modes[i].bits_per_pixel; } else { res_mode = (struct ctfb_res_modes *) &var_mode; bits_per_pixel = video_get_params (res_mode, penv); } /* calculate hsynch and vsynch freq (info only) */ t1 = (res_mode->left_margin + res_mode->xres + res_mode->right_margin + res_mode->hsync_len) / 8; t1 *= 8; t1 *= res_mode->pixclock; t1 /= 1000; hsynch = 1000000000L / t1; t1 *= (res_mode->upper_margin + res_mode->yres + res_mode->lower_margin + res_mode->vsync_len); t1 /= 1000; vsynch = 1000000000L / t1; /* fill in Graphic device struct */ sprintf (pGD->modeIdent, "%dx%dx%d %ldkHz %ldHz", res_mode->xres, res_mode->yres, bits_per_pixel, (hsynch / 1000), (vsynch / 1000)); printf ("%s\n", pGD->modeIdent); pGD->winSizeX = res_mode->xres; pGD->winSizeY = res_mode->yres; pGD->plnSizeX = res_mode->xres; pGD->plnSizeY = res_mode->yres; switch (bits_per_pixel) { case 8: pGD->gdfBytesPP = 1; pGD->gdfIndex = GDF__8BIT_INDEX; break; case 15: pGD->gdfBytesPP = 2; pGD->gdfIndex = GDF_15BIT_555RGB; break; case 16: pGD->gdfBytesPP = 2; pGD->gdfIndex = GDF_16BIT_565RGB; break; case 24: pGD->gdfBytesPP = 3; pGD->gdfIndex = GDF_24BIT_888RGB; break; } /* statically configure settings */ pGD->winSizeX = pGD->plnSizeX = 320; pGD->winSizeY = pGD->plnSizeY = 240; pGD->gdfBytesPP = 2; pGD->gdfIndex = GDF_16BIT_565RGB; pGD->frameAdrs = LCD_VIDEO_ADDR; pGD->memSize = VIDEO_MEM_SIZE; board_video_init(pGD); lcd->LCDSADDR1 = pGD->frameAdrs >> 1; /* This marks the end of the frame buffer. */ lcd->LCDSADDR2 = (lcd->LCDSADDR1&0x1fffff) + (pGD->winSizeX+0) * pGD->winSizeY; lcd->LCDSADDR3 = (pGD->winSizeX & 0x7ff); /* Clear video memory */ memset((void *)pGD->frameAdrs, 0, pGD->memSize); /* Enable Display */ lcd->LCDCON1 |= 0x01; /* ENVID = 1 */ return ((void*)&smi); } void video_set_lut (unsigned int index, /* color number */ unsigned char r, /* red */ unsigned char g, /* green */ unsigned char b /* blue */ ) { } #endif /* CONFIG_VIDEO_S3C2410 */

在你的配置头文件中添加如下宏定义：

#define CONFIG_CMD_BMP #define CONFIG_VIDEO #define CONFIG_VIDEO_S3C2410 #define CONFIG_VIDEO_LOGO #define VIDEO_FB_16BPP_PIXEL_SWAP #define CONFIG_VIDEO_SW_CURSOR #define CONFIG_VIDEO_BMP_LOGO

这样就基本完成了，重新启动一下是不是就显示出samsung的logo了。如果先改成自己喜欢的图片，修改tools/logos/denx.bmp，记住一定是是8bpp的bmp图，修改Makefile文件，修改/tools目录下的Makefile文件，大约是44~46行，

jpegtopnm $1 | ppmquant 31 | ppmtobmp -bpp 8 > $2

这样就可以显示出你自己喜欢的logo图片了。

如果想将串口的打印信息显示在lcd上，添加环境变量。

#define CONFIG_EXTRA_ENV_SETTINGS \ "stdin=serial\0" \ "stdout=vga" \ "stderr=serial\0" \

只要让stdout等于vga就可以了。在lib_arm/board.c文件中可以看到console_init初始化两次，我们修改的影响第二次的初始化，第一次的不影响，所以还会有部分输出信息显示在串口上的。Lcd就到这里，有什么问题我再及时改正吧。