
| Checkpoint | Description | 
| 39 | Initializes  | 
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| 3A | Initialize RTC date/time. | 
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| 3B | Test for total memory installed in the system. Also, Check for DEL or ESC | 
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 | keys to limit memory test. Display total memory in the system. | 
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| 3C | Mid POST initialization of chipset registers. | 
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| 40 | Detect different devices (Parallel ports, serial ports, and coprocessor in CPU, … | 
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| 
 | etc.) successfully installed in the system and update the BDA, EBDA…etc. | 
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| 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  | 
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| 75 | Initialize  | 
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| 78 | Initializes IPL devices controlled by BIOS and option ROMs. | 
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| 7C | Generate and write contents of ESCD in NVRam. | 
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| 84 | Log errors encountered during POST. | 
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| 85 | Display errors to the user and gets the user response for error. | 
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| 87 | Execute BIOS setup if needed / requested. Check boot password if | 
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 | installed. | 
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| 8C | Late POST initialization of chipset registers. | 
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| 8D | Build ACPI tables (if ACPI is supported) | 
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| 8E | Program the peripheral parameters. Enable/Disable NMI as selected | 
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| 90 | Initialize system management interrupt by invoking all handlers. | 
| 
 | Please note this checkpoint comes right after checkpoint 20h | 
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| A1 | 
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69