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Added a relaxed MMU\Page Structure overview |
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The structure of the above in computer speak is quite simple. Each entry is the address of it's child. If it's a directory entry, the entry consists of the table's address. Moreover, if it's a table's entry we're talking about, then it's the the address of the mapped physical memory. |
The structure of the above in computer speak is quite simple. Each entry is the address of it's child. If it's a directory entry, the entry consists of the table's address. Moreover, if it's a table's entry we're talking about, then it's the the address of the mapped physical memory. |
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A short note, however, just to ruin your simplicity. Each entry described above also contains |
A short note, however, just to ruin your simplicity. Each entry described above also contains several flags. As this is a relaxed overview, I'll only list the three major ones here: |
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*Bits 31- |
*Bits 31-12: 4kb aligned address of entry |
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*Bit 2: User\Supervisor |
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*Bit 2: Modified flag - Pages with this set must be copied to disk before deletion. |
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*Bit 1: Read\Write |
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*Bit 1: Used Flag - While set, the MMU assumes that this page is actively mapped to some physical address. |
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*Bit 0: Presence Flag - While set, the MMU will assume that this page is currently in memory. |
*Bit 0: Presence Flag - While set, the MMU will assume that this page is currently in memory. |
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