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Diffstat (limited to 'notes.txt')
| -rw-r--r-- | notes.txt | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/notes.txt b/notes.txt new file mode 100644 index 0000000..9016799 --- /dev/null +++ b/notes.txt @@ -0,0 +1,23 @@ + /* Defenitions: + * Segment: + * A logically contiguous chunk of memory with consistent properties from the cpus perspective + * - Just a bunch of memory dedicated for a specific purpose + * Segment Register: + * A register of the CPU that refers to a segment for a particular purpose (CS, DS, SS, ES) + * or for general use. (FS, GS) + * - Code segment, Data segment, ... + * Segment Selector: + * A reference to a descriptor, which you can load into a segment register; the selector is an offset + * into a descriptor table pointing to one of its entries. + * These entries are typically 8 bytes long, therefore + * bits 3 and up only declare the descriptor table entry offset + * bit 2 specifies GDT or LDT + * bits 0-1 declare ring level that needs to correspond to the descriptor table entry's DPL field. + * GENERAL PROTECTION FAULT if it doesn't + * If it does correspond then the CPL level of the selector used is changed accordingly + * - A pointer to an entry in the DT + * Segment Descriptor: + * An entry in a descriptor table. + * These are a binary data structure that tells the CPU the attributes of a given segment + * - A binary number that describes a segment + */ |