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The boot code in the BCM7208 instructs it to continue the boot process by reading additional code from the onboard NAND flash, which can be updated in the field, either from on the flash slots or USB mass storage. Part of the NAND flash is also used to hold non-volatile parameters. The contents of the boot flash are copied into the SDRAM. The CPU then jumps to the boot code.
SDRAM
The HD120, HD220, and HD1020 players each contain one DDR SDRAM device. When the BCM7208 boots, it will copy the code from the NAND flash device into the SDRAM and then execute the code from the SDRAM. The SDRAM runs at a clock rate of 666MHz, with a data rate of 1333MHz.
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There are four on-board LEDs that indicate the following:
LED | Indication | |
Green power | Flashes any time the board is powered up and not in reset mode. | |
Green flash activity | Flashes any time there is CPU activity. | |
Yellow update | Flashes when the board is being upgraded. | |
Red status | Flashes a certain number of times to indicate which error is occurring. The flash codes are described below. | |
2 | Unspecified error | |
3 | Network recovery script is preparing to run on a device configured for network recovery. | |
4 | No upgrade file found | |
5 | Failed to load kernel module | |
6 | Board is not capable of running the current firmware version. | |
7 | Problem related to the Ethernet chip | |
7 | A piece of on-board hardware is not working correctly (on firmware versions 4.1 and later). | |
8 | Problem related to the storage device (either the USB drive or SD card) | |
9 | Problem related to the registry/EEPROM | |
10 | The autorun script encountered a load/run error. | |
11 | WiFi-related error (mainly, WiFi not found on USB) | |
12 | Unable to find a bootable image (on firmware versions 4.0 and later) | |
On-Board Switch
The on-board switch is connected to the GPIO32. A pullup on the button normally sets the GPIO32 to be pulled high. Conversely, the GPIO32 is pulled low when the button is pressed.
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The USB 2.0 high-speed host controller is implemented internally in the BCM2708 SOC chip. The board utilizes the TPS2065 device, which is over-current protected switch: It can be used to turn the power to the USB device on or off or to detect over-current situations.