SkyEye硬件模拟平台，第三部分: 硬件仿真实现之五

//lcd控制寄存器地址
#define LCDCON	0x02c0	/* LCD Control register */
#define VBUFSIZ	0x00001fff
/* Video buffer size (bits/128-1) */
#define LINELEN	0x0007e000
/* Line length (pix/16-1) */
#define LINELEN_SHIFT	13
#define PIXPSC	0x01f80000
/* Pixel prescale (526628/pixels-1) */
#define PIXPSC_SHIFT	19
#define ACPSC	0x3e000000
/* AC prescale */
#define ACPSC_SHIFT	25
//下面两个控制lcd是单色、4级灰度或16级灰度（每个像素点有几位决定灰度级）
#define GSEN	0x40000000
/* Grayscale enable (0: monochrome) */
#define GSMD	0x80000000
/* Grayscale mode (0: 2 bit, 1: 4 bit) */
//SYSCON寄存器的一位，控制lcd是否enable（SYSCON就是state->io.syscon）
#define	LCDEN	0x00001000
/* LCD enable */

state->mach_io.lcdcon
=(ARMword *)&io.lcdcon;
// lcd控制寄存器
state->mach_io.lcd_is_enable
=(ARMword *)&io.lcd_is_enable;
// 是否打开lcd
state->mach_io.lcd_addr_begin	=(ARMword *)&io.lcd_addr_begin; // lcd显示内存起始地址
state->mach_io.lcd_addr_end
=(ARMword *)&io.lcd_addr_end;
// lcd显示内存结束地址

switch (addr - 0x80000000) {
//如果用户写系统控制寄存器，让lcd的状态从关闭变为打开，则重新初始化lcd。
case SYSCON:
tmp = io.syscon;
io.syscon = data;
//chy 2004-03-11
if ((tmp & LCDEN) != (data & LCDEN)) {
ep7312_update_lcd(state);
}
break;
… …
//如果用户改写lcd控制寄存器，改变lcd的控制参数，则重新初始化lcd
case LCDCON:
tmp = io.lcdcon;
io.lcdcon = data;
//chy 2004-03-11 tmp compare with data
if ((tmp & (VBUFSIZ|LINELEN|GSEN|GSMD)) != (data & (VBUFSIZ|LINELEN|GSEN|GSMD))) {
ep7312_update_lcd(state);
}
break;
… …
}
//在应用程序改写SYSCON或LCDCON时,重新初始化LCD时被调用
static void ep7312_update_lcd(ARMul_State *state)
{
ep7312_lcd_disable(state);
if (io.syscon & LCDEN) {
ARMword lcdcon = io.lcdcon;
ARMword vbufsiz = lcdcon & VBUFSIZ;
ARMword linelen = (lcdcon & LINELEN) >> LINELEN_SHIFT;
int width, height, depth;
switch (lcdcon & (GSEN|GSMD)) {
case GSEN:
depth = 2;
break;
case GSEN|GSMD:
depth = 4;
break;
default:
depth = 1;
break;
}
width = (linelen + 1) * 16;
height = (vbufsiz + 1) * 128 / depth / width;
//以上是取得lcd的高，宽，像素位数（都从LCDCON寄存器中来）
//使用以上参数重新初始化lcd
ep7312_lcd_enable(state, width, height, depth);
}
}

//当LCDCON寄存器被改写时,调用lcd_enable重新初始化lcd仿真屏幕窗口
void lcd_enable(ARMul_State *state, int width, int height, int depth)
{
int i;
static int once = 0;
GdkColor tmpColor;
char * title;
char mode[100];
if(skyeye_config.no_lcd){
return;
}//如果不使用lcd,则返回
if (!once) {
once++;
gtk_init(&global_argc, &global_argv);
}//只在第一次运行时初始化一个gtk模拟出的lcd屏幕窗口
lcd_width = width;
//lcd仿真屏幕宽度
lcd_height = height;
//lcd仿真屏幕高度
lcd_depth = depth;
//表示一个象素所用的bit数（决定颜色深度）
*(state->mach_io.lcd_is_enable)=1;
//根据显示模式计算lcd显示内存的结束地址
*(state->mach_io.lcd_addr_end) = *(state->mach_io.lcd_addr_begin) + (width * height * depth / 8);
printf("SKYEYE:
lcd_addr_begin 0x%x,lcd_addr_end 0x%x, width %d, height %d, depth %d/n",*(state->mach_io.lcd_addr_end),
*(state->mach_io.lcd_addr_begin),width, height,depth);
//建立顶层窗口
window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
//初始化gtk窗口，包括窗口标题,窗口大小等
title="SkyEye_LcdScreen_TouchScreen ";
sprintf(mode,"%s%dx%dx%d",title,lcd_width,lcd_height,lcd_depth);
gtk_window_set_title(window, mode);
gtk_widget_set_usize(window, width, height);
//把"expose_event"和顶层窗口的信号处理器联系起来
gtk_signal_connect(GTK_OBJECT(window), "expose_event",
(GtkSignalFunc)expose_event, NULL);
gtk_widget_set_events(window, GDK_EXPOSURE_MASK);
//建立触摸屏仿真事件盒容器,这在skyeye的触摸屏仿真中会用到,此处不进行详细分析
TouchScreen = gtk_event_box_new ( );
gtk_container_add (GTK_CONTAINER (window), TouchScreen);
gtk_widget_set_events(GTK_OBJECT(TouchScreen), GDK_ENTER_NOTIFY_MASK
| GDK_LEAVE_NOTIFY_MASK
| GDK_BUTTON_PRESS_MASK
| GDK_BUTTON_RELEASE_MASK
| GDK_POINTER_MOTION_HINT_MASK);
gtk_signal_connect (GTK_OBJECT(TouchScreen), "button-press-event",
GTK_SIGNAL_FUNC (callback_button_press), NULL);
gtk_signal_connect (GTK_OBJECT(TouchScreen), "button-release-event",
GTK_SIGNAL_FUNC (callback_button_release), NULL);
gtk_signal_connect (GTK_OBJECT(TouchScreen), "motion-notify-event",
GTK_SIGNAL_FUNC (callback_motion_notify), NULL);
gtk_widget_show (TouchScreen);
gtk_widget_realize (TouchScreen);
gdk_window_set_cursor (TouchScreen->window,gdk_cursor_new (GDK_HAND2));
//建立LCD屏幕仿真绘图窗口
LCD = gtk_drawing_area_new ();
gtk_container_add (GTK_CONTAINER (TouchScreen), LCD);
//显示LCD屏幕仿真绘图窗口
gtk_widget_show (LCD);
//显示顶层窗口
gtk_widget_show(window);
colormap = gdk_window_get_colormap(LCD->window);
/*单色,4色,16色,256色都需要调色板调出RGB颜色*/
switch (lcd_depth) {
case 1:
for (i = 0; i < 2; i++){
tmpColor= color2[i];
gdk_color_alloc (colormap, &tmpColor);
gc[i] = gdk_gc_new(LCD->window);
gdk_gc_set_foreground(gc[i], &tmpColor);
}
break;
case 2:
for (i = 0; i < 4; i++){
tmpColor= color4[i];
gdk_color_alloc (colormap, &tmpColor);
gc[i] = gdk_gc_new(LCD->window);
gdk_gc_set_foreground(gc[i], &tmpColor);
}
break;
case 4:
for (i = 0; i < 16; i++){
tmpColor= color16[i];
gdk_color_alloc (colormap, &tmpColor);
gc[i] = gdk_gc_new(LCD->window);
gdk_gc_set_foreground(gc[i], &tmpColor);
}
break;
case 8:
for (i = 0; i < 256; i++){
tmpColor= color256[i];
gdk_color_alloc (colormap, &tmpColor);
gc[i] = gdk_gc_new(LCD->window);
gdk_gc_set_foreground(gc[i], &tmpColor);
}
break;
default:
break;
}
}
//对lcd屏幕仿真窗口重新初始化时,要先调用lcd_disable释放资源并关闭原来的窗口
void lcd_disable(ARMul_State *state)
{
int i;
if (skyeye_config.no_lcd)
return;
//chy 2004-03-11
*(state->mach_io.lcd_is_enable)=0;
if(lcd_depth<=8){
for (i = 0; i <2^lcd_depth ; i++) {
if (gc[i]) {
gdk_gc_destroy(gc[i]);
gc[i] = NULL;
}
}
}//释放GdkGC(Gdk图形设备上下文）
if (window) {
gtk_widget_destroy(window);
window = NULL;
}//关闭模拟lcd屏幕的gtk window
}
lcd_cycle(ARMul_State *state)
{
gtk_main_iteration_do(FALSE);
}
/*无阻塞地检查gtk模拟出的lcd window中是否有事件需要相应的事件回调函数处理（如expose_event, motion_notify_event，button_press_event等），
这些事件是在lcd_enable中注册的。SkyEye模拟ep7312时,本函数在skyeye_mach_ep7312.c的函数ep7312_io_do_cycle中被调用,
最终是被armio.c中的io_do_cycle调用，也就是每个时钟执行一次。
当对lcd显示内存进行写操作时,lcd_write会被调用,将相应的象素画到lcd屏幕仿真窗口上*/
void lcd_write(ARMul_State *state, ARMword addr, ARMword data)
{
ARMword offset;
int pixnum, x, y, bit;
int pix;
GdkColor color;
//如果不使用lcd,则返回
if (skyeye_config.no_lcd)
return;
//根据象素所在的4字节的地址,计算该4字节所包含的第一个象素对应于在lcd仿真屏幕上的坐标
offset = (addr & ~3) - LCD_BASE;
pixnum = offset * 8/ lcd_depth;
x = pixnum % lcd_width;
y = pixnum / lcd_width;
assert(y < lcd_height);
//调用gdk画点函数gdk_draw_point画出该4字节所包含的所有象素点
//当颜色深度等于 1时,要画32个点
//当颜色深度等于 2时,要画16个点
//当颜色深度等于 4时,要画8个点
//当颜色深度等于 8时,要画4个点
//当颜色深度等于16时,要画2个点
//当颜色深度等于32时,要画1个点
for (bit = 0; bit < 32; bit += lcd_depth) {
switch (lcd_depth) {
//当颜色深度<=8时,已经根据相应的调色板调出RGB值
case 1:
case 2:
case 4:
case 8:
pix = (data >> bit) % (1 << lcd_depth);
gdk_draw_point(LCD->window, gc[pix], x, y);
x++;
break;
case 15:
break;
//当颜色深度大于8时,可以直接根据象素值调出RGB值
case 16:
pix = (data >> bit) % (1 << lcd_depth);
color.red =
(short)((pix&0x00007c00)<<1);
//rgb--->1555
color.green = (short)((pix&0x000003e0)<<6);
color.blue =
(short)((pix&0x0000001f)<<11);
gdk_color_alloc (colormap, &color);
mygc = gdk_gc_new(LCD->window);
gdk_gc_set_foreground(mygc, &color);
gdk_draw_point(LCD->window, mygc, x, y);
x++;
break;
case 24:
break;
case 32:
color.red =
((data&0x00ff0000)>>8);
color.green = ((data&0x0000ff00));
color.blue =
((data&0x000000ff)<<8);
gdk_color_alloc (colormap, &color);
mygc = gdk_gc_new(LCD->window);
gdk_gc_set_foreground(mygc, &color);
gdk_draw_point(LCD->window, mygc, x, y);
break;
default:
break;
}
}
}