
Checkpoint | Description  | 
  | 
  | 
31  | Allocate memory for ADM module and uncompress it. Give control to ADM module  | 
  | for initialization. Initialize language and font modules for ADM. Activate ADM  | 
  | module. | 
  | 
  | 
33  | Initializes the silent boot module. Set the window for displaying text information.  | 
  | 
  | 
37  | Displaying   | 
  | specific information.  | 
  | 
  | 
38  | Initializes different devices through DIM. See DIM Code Checkpoints section for  | 
  | more information. USB controllers are initialized at this point.  | 
  | 
  | 
39  | Initializes   | 
  | 
  | 
3A  | Initialize RTC date/time.  | 
  | 
  | 
3B  | Test for total memory installed in the system. Also, Check for DEL or ESC keys to  | 
  | limit memory test. Display total memory in the system.  | 
  | 
  | 
3C  | Mid POST initialization of chipset registers.  | 
  | 
  | 
40  | Detect different devices (Parallel ports, serial ports, and coprocessor in CPU, ...  | 
  | etc.) successfully installed in the system and update the BDA, EBDA…etc.  | 
  | 
  | 
50  | Programming the memory hole or any kind of implementation that needs an  | 
  | adjustment in system RAM size if needed.  | 
  | 
  | 
52  | Updates CMOS memory size from memory found in memory test. Allocates  | 
  | memory for Extended BIOS Data Area from base memory. Programming the  | 
  | memory hole or any kind of implementation that needs an adjustment in system  | 
  | RAM size if needed.  | 
  | 
  | 
60  | Initializes   | 
  | 
  | 
75  | Initialize   | 
  | 
  | 
78  | Initializes IPL devices controlled by BIOS and option ROMs.  | 
  | 
  | 
7A  | Initializes remaining option ROMs.  | 
  | 
  | 
7C  | Generate and write contents of ESCD in NVRam.  | 
  | 
  | 
84  | Log errors encountered during POST.  | 
  | 
  | 
85  | Display errors to the user and gets the user response for error.  | 
  | 
  | 
87  | Execute BIOS setup if needed / requested. Check boot password if installed.  | 
  | 
  | 
8C  | Late POST initialization of chipset registers.  | 
  | 
  | 
8D  | Build ACPI tables (if ACPI is supported)  | 
  | 
  | 
8E  | Program the peripheral parameters. Enable/Disable NMI as selected.  | 
  | 
  | 
90  | Late POST initialization of system management interrupt.  | 
  | 
  | 
A0  | Check boot password if installed.  | 
  | 
  | 
A1  | |
  | 
  | 
A2  | Takes care of runtime image preparation for different BIOS modules. Fill the free  | 
  | area in F000h segment with 0FFh. Initializes the Microsoft IRQ Routing Table.  | 
  | Prepares the runtime language module. Disables the system configuration display if  | 
  | needed.  | 
  | 
  | 
A4  | Initialize runtime language module. Display boot option popup menu.  | 
  | 
  | 
A7  | Displays the system configuration screen if enabled. Initialize the CPU’s before  | 
  | boot, which includes the programming of the MTRR’s.  | 
  | 
  | 
A8  | Prepare CPU for OS boot including final MTRR values.  | 
  | 
  | 
A9  | Wait for user input at config display if needed.  | 
  | 
  | 
AA  | Uninstall POST INT1Ch vector and INT09h vector. Deinitializes the ADM module.  | 
  | 
  | 
AB  | Prepare BBS for Int 19 boot.  | 
  | 
  | 
AC  | End of POST initialization of chipset registers.  | 
  | 
  | 
58  | Chapter 4 |