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Update linux-initialization-2.md

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Initialization/linux-initialization-2.md
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@ -115,7 +115,11 @@ Where:
* `Offset` - is offset to entry point of an interrupt handler; * `Offset` - is offset to entry point of an interrupt handler;
* `DPL` - Descriptor Privilege Level; * `DPL` - Descriptor Privilege Level;
* `P` - Segment Present flag; * `P` - Segment Present flag;
* `Segment selector` - a code segment selector in GDT or LDT * `Segment selector` - a code segment selector in GDT or LDT (actually it always point to GDT in linux)
```C
#define __KERNEL_CS (GDT_ENTRY_KERNEL_CS*8) // 0000 0000 0001 0000
#define GDT_ENTRY_KERNEL_CS 2
```
* `IST` - provides ability to switch to a new stack for interrupts handling. * `IST` - provides ability to switch to a new stack for interrupts handling.
And the last `Type` field describes type of the `IDT` entry. There are three different kinds of gates for interrupts: And the last `Type` field describes type of the `IDT` entry. There are three different kinds of gates for interrupts:
@ -164,7 +168,7 @@ where `NUM_EXCEPTION_VECTORS` expands to `32`. As we can see, We're filling only
and inserts an interrupt gate to the `IDT` table which is represented by the `&idt_descr` array. and inserts an interrupt gate to the `IDT` table which is represented by the `&idt_descr` array.
The `early_idt_handler_array` array is declaredd in the [arch/x86/include/asm/segment.h](https://github.com/torvalds/linux/blob/master/arch/x86/include/asm/segment.h) header file and contains addresses of the first `32` exception handlers: The `early_idt_handler_array` array is declared in the [arch/x86/include/asm/segment.h](https://github.com/torvalds/linux/blob/master/arch/x86/include/asm/segment.h) header file and contains addresses of the first `32` exception handlers:
```C ```C
#define EARLY_IDT_HANDLER_SIZE 9 #define EARLY_IDT_HANDLER_SIZE 9