Minix1.5/kernel/protect.h
/* Constants for protected mode. */
/* Table sizes. */
#define GDT_SIZE (FIRST_LDT_INDEX + NR_TASKS + NR_PROCS) /* spec. and LDT's */
#define IDT_SIZE (IRQ8_VECTOR + 8) /* only up to the highest vector */
#define LDT_SIZE 2 /* contains CS and DS only */
/* Fixed global descriptors. 1 to 7 are prescribed by the BIOS. */
#define BIOS_GDT_INDEX 1 /* temp spot to store pointer to GDT */
#define BIOS_IDT_INDEX 2 /* temp spot to store pointer to GDT */
#define DS_INDEX 3 /* kernel DS */
#define ES_INDEX 4 /* kernel ES */
#define SS_INDEX 5 /* kernel SS */
#define CS_INDEX 6 /* kernel CS */
#define BIOS_CS_INDEX 7 /* temp for BIOS */
#define TSS_INDEX 8 /* kernel TSS */
#define DS_286_INDEX 9 /* scratch 16-bit source segment */
#define ES_286_INDEX 10 /* scratch 16-bit destination segment */
#define FLAT_DS_INDEX 11 /* 32-bit segment seg covering all of memory */
#define COLOR_INDEX 12 /* color screen segment */
#define MONO_INDEX 13 /* mono screen segment */
#define DB_CS_INDEX 14 /* debugger CS */
#define DB_CS16_INDEX 15 /* debugger 16-bit CS for 386 */
#define DB_DS_INDEX 16 /* debugger DS */
#define GDT_INDEX 17 /* GDT DS for debugger */
#define FIRST_LDT_INDEX 18 /* rest of descriptors are LDT's */
#if AM_KERNEL
#if !NONET
#undef FIRST_LDT_INDEX
#define EPLUS_INDEX 18 /* Western Digital Etherplus buffer */
#define FIRST_LDT_INDEX 19 /* rest of descriptors are LDT's */
#endif /* NONET */
#endif /* AM_KERNEL */
#define BIOS_GDT_SELECTOR 0x08 /* (BIOS_GDT_INDEX * DESC_SIZE) bad for asld */
#define BIOS_IDT_SELECTOR 0x10 /* (BIOS_IDT_INDEX * DESC_SIZE) */
#define DS_SELECTOR 0x18 /* (DS_INDEX * DESC_SIZE) */
#define CS_SELECTOR 0x30 /* (CS_INDEX * DESC_SIZE) */
#define BIOS_CS_SELECTOR 0x38 /* (BIOS_CS_INDEX * DESC_SIZE) */
#define TSS_SELECTOR 0x40 /* (TSS_INDEX * DESC_SIZE) */
#define DS_286_SELECTOR 0x49 /* (DS_286_INDEX * DESC_SIZE + 1) */
#define ES_286_SELECTOR 0x51 /* (ES_286_INDEX * DESC_SIZE + 1) */
#define FLAT_DS_SELECTOR 0x59 /* (FLAT_DS_INDEX * DESC_SIZE + 1) */
#define COLOR_SELECTOR 0x61 /* (COLOR_INDEX * DESC_SIZE + 1) */
#define MONO_SELECTOR 0x69 /* (MONO_INDEX * DESC_SIZE + 1) */
#define DB_CS_SELECTOR 0x70 /* (DB_CS_INDEX * DESC_SIZE) */
#define DB_CS16_SELECTOR 0x78 /* (DB_CS16_INDEX * DESC_SIZE) */
#define DB_DS_SELECTOR 0x80 /* (DB_DS_INDEX * DESC_SIZE) */
#define GDT_SELECTOR 0x88 /* (GDT_INDEX * DESC_SIZE) */
#if AM_KERNEL
#if !NONET
#define EPLUS_SELECTOR 0x91 /* (EPLUS_INDEX * DESC_SIZE) */
#endif /* AM_KERNEL */
#endif /* NONET */
/* Fixed local descriptors. */
#define CS_LDT_INDEX 0 /* process CS */
#define DS_LDT_INDEX 1 /* process DS=ES=FS=GS=SS */
/* Privileges. */
#define INTR_PRIVILEGE 0 /* kernel and interrupt handlers */
#define TASK_PRIVILEGE 1
#define USER_PRIVILEGE 3
/* 286 hardware constants. */
/* Exception vector numbers. */
#define BOUNDS_VECTOR 5 /* bounds check failed */
#define INVAL_OP_VECTOR 6 /* invalid opcode */
#define COPROC_NOT_VECTOR 7 /* coprocessor not available */
#define DOUBLE_FAULT_VECTOR 8
#define COPROC_SEG_VECTOR 9 /* coprocessor segment overrun */
#define INVAL_TSS_VECTOR 10 /* invalid TSS */
#define SEG_NOT_VECTOR 11 /* segment not present */
#define STACK_FAULT_VECTOR 12 /* stack exception */
#define PROTECTION_VECTOR 13 /* general protection */
/* Selector bits. */
#define TI 0x04 /* table indicator */
#define RPL 0x03 /* requester privilege level */
/* Descriptor structure offsets. */
#define DESC_BASE 2 /* to base_low */
#define DESC_BASE_MIDDLE 4 /* to base_middle */
#define DESC_ACCESS 5 /* to access byte */
#define DESC_SIZE 8 /* sizeof (struct segdesc_s) */
/* Segment sizes. */
#define MAX_286_SEG_SIZE 0x10000L
/* Base and limit sizes and shifts. */
#define BASE_MIDDLE_SHIFT 16 /* shift for base --> base_middle */
/* Access-byte and type-byte bits. */
#define PRESENT 0x80 /* set for descriptor present */
#define DPL 0x60 /* descriptor privilege level mask */
#define DPL_SHIFT 5
#define SEGMENT 0x10 /* set for segment-type descriptors */
/* Access-byte bits. */
#define EXECUTABLE 0x08 /* set for executable segment */
#define CONFORMING 0x04 /* set for conforming segment if executable */
#define EXPAND_DOWN 0x04 /* set for expand-down segment if !executable*/
#define READABLE 0x02 /* set for readable segment if executable */
#define WRITEABLE 0x02 /* set for writeable segment if !executable */
#define TSS_BUSY 0x02 /* set if TSS descriptor is busy */
#define ACCESSED 0x01 /* set if segment accessed */
/* Special descriptor types. */
#define AVL_286_TSS 1 /* available 286 TSS */
#define LDT 2 /* local descriptor table */
#define BUSY_286_TSS 3 /* set transparently to the software */
#define CALL_286_GATE 4 /* not used */
#define TASK_GATE 5 /* only used by debugger */
#define INT_286_GATE 6 /* interrupt gate, used for all vectors */
#define TRAP_286_GATE 7 /* not used */
/* Extra 386 hardware constants. */
/* Exception vector numbers. */
#define PAGE_FAULT_VECTOR 14
#define COPROC_ERR_VECTOR 16 /* coprocessor error */
/* Descriptor structure offsets. */
#define DESC_GRANULARITY 6 /* to granularity byte */
#define DESC_BASE_HIGH 7 /* to base_high */
/* Base and limit sizes and shifts. */
#define BASE_HIGH_SHIFT 24 /* shift for base --> base_high */
#define BYTE_GRAN_MAX 0xFFFFFL /* maximum size for byte granular segment */
#define GRANULARITY_SHIFT 16 /* shift for limit --> granularity */
#define OFFSET_HIGH_SHIFT 16 /* shift for (gate) offset --> offset_high */
#define PAGE_GRAN_SHIFT 12 /* extra shift for page granular limits */
/* Type-byte bits. */
#define DESC_386_BIT 0x08 /* 386 types are obtained by ORing with this */
/* LDT's and TASK_GATE's don't need it */
/* Granularity byte. */
#define GRANULAR 0x80 /* set for 4K granularilty */
#define DEFAULT 0x40 /* set for 32-bit defaults (executable seg) */
#define BIG 0x40 /* set for "BIG" (expand-down seg) */
#define AVL 0x10 /* 0 for available */
#define LIMIT_HIGH 0x0F /* mask for high bits of limit */