3.1.2.4. U-Boot Splash Screen¶
Adding a splash screen
AM335x
All the code below is based on Processor Linux SDK 03.02.00..05.
There is a frame buffer driver for am335x in the drivers/video directory called am3355x-fb.c. It makes calls to routines in board.c to set up the LCDC and frame buffer. To use it:
Either create a new defconfig in the configs directory or just add SPLASH to CONFIG_SYS_EXTRA_OPTIONS. In this example the am335x_evm_defconfig is copied into a new one called am335x_evm_splash_defconfig.
CONFIG_TARGET_AM335X_EVM=y
CONFIG_SPL_STACK_R_ADDR=0x82000000
CONFIG_DEFAULT_DEVICE_TREE="am335x-evm"
CONFIG_SPL=y
CONFIG_SPL_STACK_R=y
CONFIG_SYS_EXTRA_OPTIONS="NAND,SPLASH"
CONFIG_HUSH_PARSER=y
CONFIG_AUTOBOOT_KEYED=y
In include/configs/am335x_evm.h, add support for the splash screen, LCDC, and gzipped bitmaps.
/* Splash scrren support */
#ifdef CONFIG_SPLASH
#define CONFIG_AM335X_LCD
#define CONFIG_LCD
#define CONFIG_LCD_NOSTDOUT
#define CONFIG_SYS_WHITE_ON_BLACK
#define LCD_BPP LCD_COLOR16
#define CONFIG_VIDEO_BMP_GZIP
#define CONFIG_SYS_VIDEO_LOGO_MAX_SIZE (1366*767*4)
#define CONFIG_CMD_UNZIP
#define CONFIG_CMD_BMP
#define CONFIG_BMP_16BPP
#endif
In arch/arm/cpu/armv7/am33xx/clock_am33xx.c enable the LCDC clocks.
&cmrtc->rtcclkctrl,
&cmper->usb0clkctrl,
&cmper->emiffwclkctrl,
&cmper->emifclkctrl,
&cmper->lcdclkctrl,
&cmper->lcdcclkstctrl,
&cmper->epwmss2clkctrl,
0
In board.c add includes for mmc, fat, lcd, and the frame buffer.
#include <libfdt.h>
#include <fdt_support.h>
#include <mmc.h>
#include <fat.h>
#include <lcd.h>
#include <../../../drivers/video/am335x-fb.h>
This example code is based on the AM335x Starter Kit. A GPIO controls the backlight so use GPIO_TO_PIN to define the GPIO.
#define GPIO_ETH1_MODE GPIO_TO_PIN(1, 26)
/* GPIO that controls backlight on EVM-SK */
#define GPIO_BACKLIGHT_EN GPIO_TO_PIN(3, 17)
In board_late_init call the splash screen routine.
#if !defined(CONFIG_SPL_BUILD)
splash_screen();
/* try reading mac address from efuse */
mac_lo = readl(&cdev->macid0l);
mac_hi = readl(&cdev->macid0h);
The following routines enable the backlight, load the LCD timings (this example is based on Starter Kit), power on the LCD and enable it, then finally the splash screen code that registers a fat file system on mmc0. The gzipped bitmap is named splash.bmp.gz and is displayed with bmp_display.
#if defined(CONFIG_LCD) && defined(CONFIG_AM335X_LCD) && \
!defined(CONFIG_SPL_BUILD)
void lcdbacklight(int on)
{
gpio_request(GPIO_BACKLIGHT_EN, "backlight_en");
if (on)
gpio_direction_output(GPIO_BACKLIGHT_EN, 0);
else
gpio_direction_output(GPIO_BACKLIGHT_EN, 1);
}
int load_lcdtiming(struct am335x_lcdpanel *panel)
{
struct am335x_lcdpanel pnltmp;
pnltmp.hactive = 480;
pnltmp.vactive = 272;
pnltmp.bpp = 16;
pnltmp.hfp = 8;
pnltmp.hbp = 43;
pnltmp.hsw = 4;
pnltmp.vfp = 4;
pnltmp.vbp = 12;
pnltmp.vsw = 10;
pnltmp.pxl_clk_div = 2;
pnltmp.pol = 0;
pnltmp.pup_delay = 1;
pnltmp.pon_delay = 1;
panel_info.vl_rot = 0;
memcpy((void *)panel, (void *)&pnltmp, sizeof(struct am335x_lcdpanel));
return 0;
}
void lcdpower(int on)
{
lcd_enable();
}
vidinfo_t panel_info = {
.vl_col = 480,
.vl_row = 272,
.vl_bpix = 4,
.priv = 0
};
void lcd_ctrl_init(void *lcdbase)
{
struct am335x_lcdpanel lcd_panel;
memset(&lcd_panel, 0, sizeof(struct am335x_lcdpanel));
if (load_lcdtiming(&lcd_panel) != 0)
return;
lcd_panel.panel_power_ctrl = &lcdpower;
if (am335xfb_init(&lcd_panel) != 0)
printf("ERROR: failed to initialize video!");
/* Modify panel into to real resolution */
panel_info.vl_col = lcd_panel.hactive;
panel_info.vl_row = lcd_panel.vactive;
// lcd_set_flush_dcache(1);
}
void lcd_enable(void)
{
lcdbacklight(1);
}
void splash_screen(void)
{
struct mmc *mmc = NULL;
int err;
mmc = find_mmc_device(0);
if (!mmc)
printf("Error finding mmc device\n");
mmc_init(mmc);
err = fat_register_device(&mmc->block_dev,
CONFIG_SYS_MMCSD_FS_BOOT_PARTITION);
if (!err) {
err = file_fat_read("splash.bmp.gz", (void *)0x82000000, 0);
bmp_display(0x82000000, 0, 0);
}
}
#endif
In mux.c define the LCDC pin mux.
#ifdef CONFIG_AM335X_LCD
static struct module_pin_mux lcd_pin_mux[] = {
{OFFSET(lcd_data0), (MODE(0) | PULLUDDIS)}, /* LCD-Data(0) */
{OFFSET(lcd_data1), (MODE(0) | PULLUDDIS)}, /* LCD-Data(1) */
{OFFSET(lcd_data2), (MODE(0) | PULLUDDIS)}, /* LCD-Data(2) */
{OFFSET(lcd_data3), (MODE(0) | PULLUDDIS)}, /* LCD-Data(3) */
{OFFSET(lcd_data4), (MODE(0) | PULLUDDIS)}, /* LCD-Data(4) */
{OFFSET(lcd_data5), (MODE(0) | PULLUDDIS)}, /* LCD-Data(5) */
{OFFSET(lcd_data6), (MODE(0) | PULLUDDIS)}, /* LCD-Data(6) */
{OFFSET(lcd_data7), (MODE(0) | PULLUDDIS)}, /* LCD-Data(7) */
{OFFSET(lcd_data8), (MODE(0) | PULLUDDIS)}, /* LCD-Data(8) */
{OFFSET(lcd_data9), (MODE(0) | PULLUDDIS)}, /* LCD-Data(9) */
{OFFSET(lcd_data10), (MODE(0) | PULLUDDIS)}, /* LCD-Data(10) */
{OFFSET(lcd_data11), (MODE(0) | PULLUDDIS)}, /* LCD-Data(11) */
{OFFSET(lcd_data12), (MODE(0) | PULLUDDIS)}, /* LCD-Data(12) */
{OFFSET(lcd_data13), (MODE(0) | PULLUDDIS)}, /* LCD-Data(13) */
{OFFSET(lcd_data14), (MODE(0) | PULLUDDIS)}, /* LCD-Data(14) */
{OFFSET(lcd_data15), (MODE(0) | PULLUDDIS)}, /* LCD-Data(15) */
{OFFSET(gpmc_ad8), (MODE(1) | PULLUDDIS)}, /* LCD-Data(16) */
{OFFSET(gpmc_ad9), (MODE(1) | PULLUDDIS)}, /* LCD-Data(17) */
{OFFSET(gpmc_ad10), (MODE(1) | PULLUDDIS)}, /* LCD-Data(18) */
{OFFSET(gpmc_ad11), (MODE(1) | PULLUDDIS)}, /* LCD-Data(19) */
{OFFSET(gpmc_ad12), (MODE(1) | PULLUDDIS)}, /* LCD-Data(20) */
{OFFSET(gpmc_ad13), (MODE(1) | PULLUDDIS)}, /* LCD-Data(21) */
{OFFSET(gpmc_ad14), (MODE(1) | PULLUDDIS)}, /* LCD-Data(22) */
{OFFSET(gpmc_ad15), (MODE(1) | PULLUDDIS)}, /* LCD-Data(23) */
{OFFSET(lcd_vsync), (MODE(0) | PULLUDDIS)}, /* LCD-VSync */
{OFFSET(lcd_hsync), (MODE(0) | PULLUDDIS)}, /* LCD-HSync */
{OFFSET(lcd_ac_bias_en), (MODE(0) | PULLUDDIS)},/* LCD-DE */
{OFFSET(lcd_pclk), (MODE(0) | PULLUDDIS)}, /* LCD-CLK */
/* backlight */
{OFFSET(mcasp0_ahclkr), (MODE(7) | PULLUDDIS)}, /* mcasp0_gpio */
{-1},
};
#endif
And enable the LCD.
} else if (board_is_evm_sk()) {
/* Starter Kit EVM */
configure_module_pin_mux(i2c1_pin_mux);
configure_module_pin_mux(gpio0_7_pin_mux);
configure_module_pin_mux(rgmii1_pin_mux);
configure_module_pin_mux(mmc0_pin_mux_sk_evm);
#ifdef CONFIG_AM335X_LCD
configure_module_pin_mux(lcd_pin_mux);
#endif
} else if (board_is_bone_lt()) {