android系统启动模式

android的启动模式会在u-boot中进行判断和处理:

1, arch/arm/mach-rockchip/boot_rkimg.c

setup_download_mode---> if (rockchip_dnl_key_pressed() || is_hotkey(HK_ROCKUSB_DNL))--->判断按键

                                                                                       --->rockchip_u2phy_vbus_detect: 判断usb

                                                                                                     ---->env_set("reboot_mode", "recovery-key")   :设置uboot环境变量

2,arch/arm/mach-rockchip/boot_mode.c

rockchip_get_boot_mode--->

                                                 env_reboot_mode = env_get("reboot_mode");
                                                 if (env_reboot_mode) {
                                                           if (!strcmp(env_reboot_mode, "recovery-key")) {
                                                                  return BOOT_MODE_RECOVERY;----------------------------------->物理按键进入recovery

/* Recovery mode from:
 *      - Android BCB in misc.img
 *      - "reboot recovery" command
 *      - recovery key pressed without usb attach
 */