BIOS Overview
Checkpoint | POST Routine Description | |
Code | ||
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24 | To do any setup before Int vector init. | |
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25 | Interrupt vector initialization about to begin. To clear password if necessary. | |
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27 | Any initialization before setting video mode to be done. | |
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28 | Going for monochrome mode and color mode setting. | |
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2A | Different BUSes init (system, static, output devices) to start if present. | |
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2B | To give control for any setup required before optional video ROM check. | |
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2C | To look for optional video ROM and give control. | |
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2D | To give control to do any processing after video ROM returns control. | |
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2E | If EGA/VGA not found then do display memory R/W test. | |
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2F | EGA/VGA not found. Display memory R/W test about to begin. | |
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30 | Display memory R/W test passed. About to look for the retrace checking. | |
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31 | Display memory R/W test or retrace checking failed. To do alternate Display memory R/W test. | |
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32 | Alternate Display memory R/W test passed. To look for the alternate display retrace checking. | |
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34 | Video display checking over. Display mode to be set next. | |
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37 | Display mode set. Going to display the power on message. | |
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38 | Different BUSes init (input, IPL, general devices) to start if present. | |
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39 | Display different BUSes initialization error messages. | |
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3A | New cursor position read and saved. To display the Hit <DEL> message. | |
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40 | To prepare the descriptor tables. | |
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42 | To enter in virtual mode for memory test. | |
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43 | To enable interrupts for diagnostics mode. | |
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44 | To initialize data to check memory wrap around at 0:0. | |
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45 | Data initialized. Going to check for memory wrap around at 0:0 and finding the total system memory size. | |
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46 | Memory wrap around test done. Memory size calculation over. About to go for writing patterns to test memory. | |
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47 | Pattern to be tested written in extended memory. Going to write patterns in base 640k memory. | |
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48 | Patterns written in base memory. Going to find out amount of memory below 1M memory. | |
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49 | Amount of memory below 1M found and verified. Going to find out amount of memory above 1M memory. | |
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4B | Amount of memory above 1M found and verified. Check for soft reset and going to clear memory below 1M for soft | |
| reset. (If power on, go to check point# 4Eh). | |
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4C | Memory below 1M cleared. (SOFT RESET) Going to clear memory above 1M. | |
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4D | Memory above 1M cleared. (SOFT RESET) Going to save the memory size. (Goto check point# 52h). | |
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4E | Memory test started. (NOT SOFT RESET) About to display the first 64k memory size. | |
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4F | Memory size display started. This will be updated during memory test. Going for sequential and random memory test. | |
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50 | Memory testing/initialization below 1M complete. Going to adjust displayed memory size for relocation/shadow. | |
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51 | Memory size display adjusted due to relocation/ shadow. Memory test above 1M to follow. | |
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52 | Memory testing/initialization above 1M complete. Going to save memory size information. | |
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53 | Memory size information is saved. CPU registers are saved. Going to enter in real mode. | |
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54 | Shutdown successful, CPU in real mode. Going to disable gate A20 line and disable parity/NMI. | |
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57 | A20 address line, parity/NMI disable successful. Going to adjust memory size depending on relocation/shadow. | |
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58 | Memory size adjusted for relocation/shadow. Going to clear Hit <DEL> message. | |
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Evo D310 Micro Desktop 49
