125 lines
		
	
	
		
			5.7 KiB
		
	
	
	
		
			C
		
	
	
		
			Executable File
		
	
	
	
	
			
		
		
	
	
			125 lines
		
	
	
		
			5.7 KiB
		
	
	
	
		
			C
		
	
	
		
			Executable File
		
	
	
	
	
| /* Constants for protected mode. */
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| 
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| /* Table sizes. */
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| #define GDT_SIZE (FIRST_LDT_INDEX + NR_TASKS + NR_PROCS) 
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| 					/* spec. and LDT's */
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| #define IDT_SIZE (IRQ8_VECTOR + 8)	/* only up to the highest vector */
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| #define LDT_SIZE (2 + NR_REMOTE_SEGS) 	/* CS, DS and remote segments */
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| 
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| /* Fixed global descriptors.  1 to 7 are prescribed by the BIOS. */
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| #define GDT_INDEX            1	/* GDT descriptor */
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| #define IDT_INDEX            2	/* IDT descriptor */
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| #define DS_INDEX             3	/* kernel DS */
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| #define ES_INDEX             4	/* kernel ES (386: flag 4 Gb at startup) */
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| #define SS_INDEX             5	/* kernel SS (386: monitor SS at startup) */
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| #define CS_INDEX             6	/* kernel CS */
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| #define MON_CS_INDEX         7	/* temp for BIOS (386: monitor CS at startup) */
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| #define TSS_INDEX            8	/* kernel TSS */
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| #define DS_286_INDEX         9	/* scratch 16-bit source segment */
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| #define ES_286_INDEX        10	/* scratch 16-bit destination segment */
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| #define A_INDEX             11	/* 64K memory segment at A0000 */
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| #define B_INDEX             12	/* 64K memory segment at B0000 */
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| #define C_INDEX             13	/* 64K memory segment at C0000 */
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| #define D_INDEX             14	/* 64K memory segment at D0000 */
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| #define FIRST_LDT_INDEX     15	/* rest of descriptors are LDT's */
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| 
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| #define GDT_SELECTOR      0x08	/* (GDT_INDEX * DESC_SIZE) bad for asld */
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| #define IDT_SELECTOR      0x10	/* (IDT_INDEX * DESC_SIZE) */
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| #define DS_SELECTOR       0x18	/* (DS_INDEX * DESC_SIZE) */
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| #define ES_SELECTOR       0x20	/* (ES_INDEX * DESC_SIZE) */
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| #define FLAT_DS_SELECTOR  0x21	/* less privileged ES */
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| #define SS_SELECTOR       0x28	/* (SS_INDEX * DESC_SIZE) */
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| #define CS_SELECTOR       0x30	/* (CS_INDEX * DESC_SIZE) */
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| #define MON_CS_SELECTOR   0x38	/* (MON_CS_INDEX * DESC_SIZE) */
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| #define TSS_SELECTOR      0x40	/* (TSS_INDEX * DESC_SIZE) */
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| #define DS_286_SELECTOR   0x49	/* (DS_286_INDEX*DESC_SIZE+TASK_PRIVILEGE) */
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| #define ES_286_SELECTOR   0x51	/* (ES_286_INDEX*DESC_SIZE+TASK_PRIVILEGE) */
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| 
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| /* Fixed local descriptors. */
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| #define CS_LDT_INDEX         0	/* process CS */
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| #define DS_LDT_INDEX         1	/* process DS=ES=FS=GS=SS */
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| #define EXTRA_LDT_INDEX      2	/* first of the extra LDT entries */
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| 
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| /* Privileges. */
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| #define INTR_PRIVILEGE       0	/* kernel and interrupt handlers */
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| #define TASK_PRIVILEGE       1	/* kernel tasks */
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| #define USER_PRIVILEGE       3	/* servers and user processes */
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| 
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| /* 286 hardware constants. */
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| 
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| /* Exception vector numbers. */
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| #define BOUNDS_VECTOR        5	/* bounds check failed */
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| #define INVAL_OP_VECTOR      6	/* invalid opcode */
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| #define COPROC_NOT_VECTOR    7	/* coprocessor not available */
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| #define DOUBLE_FAULT_VECTOR  8
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| #define COPROC_SEG_VECTOR    9	/* coprocessor segment overrun */
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| #define INVAL_TSS_VECTOR    10	/* invalid TSS */
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| #define SEG_NOT_VECTOR      11	/* segment not present */
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| #define STACK_FAULT_VECTOR  12	/* stack exception */
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| #define PROTECTION_VECTOR   13	/* general protection */
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| 
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| /* Selector bits. */
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| #define TI                0x04	/* table indicator */
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| #define RPL               0x03	/* requester privilege level */
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| 
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| /* Descriptor structure offsets. */
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| #define DESC_BASE            2	/* to base_low */
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| #define DESC_BASE_MIDDLE     4	/* to base_middle */
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| #define DESC_ACCESS          5	/* to access byte */
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| #define DESC_SIZE            8	/* sizeof (struct segdesc_s) */
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| 
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| /* Base and limit sizes and shifts. */
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| #define BASE_MIDDLE_SHIFT   16	/* shift for base --> base_middle */
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| 
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| /* Access-byte and type-byte bits. */
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| #define PRESENT           0x80	/* set for descriptor present */
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| #define DPL               0x60	/* descriptor privilege level mask */
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| #define DPL_SHIFT            5
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| #define SEGMENT           0x10	/* set for segment-type descriptors */
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| 
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| /* Access-byte bits. */
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| #define EXECUTABLE        0x08	/* set for executable segment */
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| #define CONFORMING        0x04	/* set for conforming segment if executable */
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| #define EXPAND_DOWN       0x04	/* set for expand-down segment if !executable*/
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| #define READABLE          0x02	/* set for readable segment if executable */
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| #define WRITEABLE         0x02	/* set for writeable segment if !executable */
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| #define TSS_BUSY          0x02	/* set if TSS descriptor is busy */
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| #define ACCESSED          0x01	/* set if segment accessed */
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| 
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| /* Special descriptor types. */
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| #define AVL_286_TSS          1	/* available 286 TSS */
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| #define LDT                  2	/* local descriptor table */
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| #define BUSY_286_TSS         3	/* set transparently to the software */
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| #define CALL_286_GATE        4	/* not used */
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| #define TASK_GATE            5	/* only used by debugger */
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| #define INT_286_GATE         6	/* interrupt gate, used for all vectors */
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| #define TRAP_286_GATE        7	/* not used */
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| 
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| /* Extra 386 hardware constants. */
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| 
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| /* Exception vector numbers. */
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| #define PAGE_FAULT_VECTOR   14
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| #define COPROC_ERR_VECTOR   16	/* coprocessor error */
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| 
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| /* Descriptor structure offsets. */
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| #define DESC_GRANULARITY     6	/* to granularity byte */
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| #define DESC_BASE_HIGH       7	/* to base_high */
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| 
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| /* Base and limit sizes and shifts. */
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| #define BASE_HIGH_SHIFT     24	/* shift for base --> base_high */
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| #define BYTE_GRAN_MAX   0xFFFFFL   /* maximum size for byte granular segment */
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| #define GRANULARITY_SHIFT   16	/* shift for limit --> granularity */
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| #define OFFSET_HIGH_SHIFT   16	/* shift for (gate) offset --> offset_high */
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| #define PAGE_GRAN_SHIFT     12	/* extra shift for page granular limits */
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| 
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| /* Type-byte bits. */
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| #define DESC_386_BIT  0x08 /* 386 types are obtained by ORing with this */
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| 				/* LDT's and TASK_GATE's don't need it */
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| 
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| /* Granularity byte. */
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| #define GRANULAR  	  0x80	/* set for 4K granularilty */
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| #define DEFAULT   	  0x40	/* set for 32-bit defaults (executable seg) */
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| #define BIG       	  0x40	/* set for "BIG" (expand-down seg) */
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| #define AVL        	  0x10	/* 0 for available */
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| #define LIMIT_HIGH   	  0x0F	/* mask for high bits of limit */
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