Intel MPCBL0010, Intel NetStructure Single Board Computer manual Warm Reset, Hard Reset

Hardware Management Overview—MPCBL0010 SBC

10.12.1Warm Reset

A warm reset occurs when the processor boots after a soft reset request. To qualify as a warm boot, the reset counter located at 40h:D0h must be non-zero (by default, the reset counter and reset flag are initialized to 10 and 1234h by the BIOS after a cold boot). Execution starts at the reset vector. The BIOS initializes and configures all devices except for memory. Memory contents remain intact except for the first 8 MB. The BIOS uses the first 8 MB during POST, but does not modify the reset flag or the reset counter. MCH is not reset, allowing DRAM refresh to continue during the warm boot.

On every warm boot, the BIOS automatically decrements the reset counter by one. When the reset counter reaches zero and the soft reset is initiated, a cold boot occurs instead of a warm boot

The front panel reset button is connected to IPMC. If the button is pushed, the IPMC outputs an active signal to the ICH’s RCIN to perform CPU init as the warm reset.

Figure 25. Warm Reset￿￿￿Block Diagram	￿￿￿￿	￿￿￿￿￿￿￿￿￿￿
￿￿￿￿￿￿￿￿		￿￿￿￿￿￿￿￿￿￿￿
		￿￿￿￿￿￿￿￿

Note: The KBRST (keyboard reset) can be used to cause a warm reset and will be detected by the IPMC.

10.12.2Hard Reset

Any reset that does not meet the configuration described in Section 10.12.1, “Warm Reset” is classified as a cold boot. Execution starts at the reset vector, and the BIOS initializes and configures all devices, including memory subsystem, as if a hard reset had occurred. During a cold boot the BIOS initializes the warm reset counter to 10h and clears the reset flag to 1234h. Software can then read the Reset flag to determine the type of reset.

10.13Field Replaceable Unit (FRU) Information

The FRU information provides inventory data about the boards where the FRU Information Device is located. The part number or version number can be read through software.

	Intel NetStructure® MPCBL0010 Single Board Computer
October 2006	Technical Product Specification
Order Number: 304120	141