Power-On Self-Test Post, Checkpoint Description

Power-On Self-Test (POST)

Each time you turn on the system, the Power-on Self Test (POST) is initiated. Several items are tested during POST, but is for the most part transparent to the user.

The Power-On Self Test (POST) is a BIOS procedure that boots the system, initializes and diagnoses the system components, and controls the operation of the power-on password option. If POST discovers errors in system operations at power-on, it displays error messages on screen, generates a check point code at port 80h or even halts the system if the error is fatal.

NOTE: When Post executes a task, it uses a series of preset numbers called check points to belatched atport 80h, indicating the stages it is currently running. This latch can be read and shown on a debug board.The following table describes the BIOS common tasks carried out by POST. Each task is denoted by an unique check point number. For other unique check point numbers that are not listed in the table, refer to the corresponding product service guide.

Post Checkpoints List: The list may vary accordingly depending on your BIOS

Bootblock Initialization Code Checkpoints

Checkpoint	Description

Before D0	If boot block debugger is enabled, CPU cache-as-RAM functionality is enabled at this
	point. Stack will be enabled from this point.

D0	Early Boot Strap Processor (BSP) initialization like microcode update, frequency and other
	CPU critical initialization. Early chipset initialization is done.

D1	Early super I/O initialization is done including RTC and keyboard controller. Serial port is
	enabled at this point if needed for debugging. NMI is disabled. Perform keyboard controller
	BAT test. Save power-on CPUID value in scratch CMOS. Go to flat mode with 4GB limit
	and GA20 enabled.

D2	Verify the boot block checksum. System will hang here if checksum is bad.

D3	Disable CACHE before memory detection. Execute full memory sizing module. If memory
	sizing module not executed, start memory refresh and do memory sizing in Boot block
	code. Do additional chipset initialization. Re-enable CACHE. Verify that flat mode is
	enabled.

D4	Test base 512KB memory. Adjust policies and cache first 8MB. Set stack.

D5	Bootblock code is copied from ROM to lower system memory and control is given to it.
	BIOS now executes out of RAM. Copies compressed boot block code to memory in right
	segments. Copies BIOS from ROM to RAM for faster access. Performs main BIOS
	checksum and updates recovery status accordingly.

D6	Both key sequence and OEM specific method is checked to determine if BIOS recovery is
	forced. If BIOS recovery is necessary, control flows to checkpoint E0. See Bootblock
	Recovery Code Checkpoints section of document for more information.

D7	Restore CPUID value back into register. The Bootblock-Runtime interface module is
	moved to system memory and control is given to it. Determine whether to execute serial
	flash.

D8	The Runtime module is uncompressed into memory. CPUID information is stored in
	memory.

D9	Store the Uncompressed pointer for future use in PMM. Copying Main BIOS into memory.
	Leaves all RAM below 1MB Read-Write including E000 and F000 shadow areas but
	closing SMRAM.

Chapter 4

M5802(G) specifications

The Acer M5802(G) is a versatile desktop computer designed to meet the demands of both home users and professionals. It showcases a blend of power, performance, and modern features that make it a competitive choice in the mid-range desktop market.

At the heart of the Acer M5802(G) lies a robust Intel processor, typically from the Core i5 or i7 range, ensuring responsiveness and efficiency in handling various tasks, from everyday computing to more intensive workloads. The multi-core architecture allows users to run multiple applications simultaneously without significant performance drops, making it ideal for multitaskers.

One of the standout features of the M5802(G) is its ample storage options. It generally comes equipped with a sizeable hard drive or SSD configuration, which not only provides plenty of space for files, applications, and media but also enhances boot and loading times. The option for SSD storage significantly improves system performance, allowing for quick access to programs and files.

Graphics capabilities are also well addressed in the Acer M5802(G). Depending on the specific configuration, it can come with integrated Intel HD graphics or an optional dedicated graphics card from AMD or NVIDIA. This makes it suitable for casual gaming, video editing, and graphic design, offering users the flexibility to engage in creative and entertainment activities.

Connectivity is a key feature of the Acer M5802(G). It is typically equipped with various USB ports, including USB 3.0 for faster data transfer, HDMI, and Ethernet ports. This enables easy connection to a variety of external devices such as printers, external storage, and monitors, enhancing the overall usability of the system.

In terms of design, the Acer M5802(G) boasts a sleek and modern chassis, making it a visually appealing addition to any workspace. The compact form factor ensures that it does not occupy excessive desk space while still housing powerful components.

In summary, the Acer M5802(G) stands out with its powerful Intel processor, generous storage options, decent graphics capabilities, and excellent connectivity options. This combination makes it an excellent choice for users looking for a dependable and robust desktop computer capable of handling diverse tasks efficiently. Whether for productivity or entertainment, the M5802(G) delivers exceptional performance in a stylish package.