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Annotation of qemu/roms/ipxe/src/arch/i386/include/pic8259.h, revision 1.1

1.1     ! root        1: /*
        !             2:  * Basic support for controlling the 8259 Programmable Interrupt Controllers.
        !             3:  *
        !             4:  * Initially written by Michael Brown (mcb30).
        !             5:  */
        !             6: 
        !             7: FILE_LICENCE ( GPL2_OR_LATER );
        !             8: 
        !             9: #ifndef PIC8259_H
        !            10: #define PIC8259_H
        !            11: 
        !            12: /* For segoff_t */
        !            13: #include "realmode.h"
        !            14: 
        !            15: #define IRQ_PIC_CUTOFF 8
        !            16: 
        !            17: /* 8259 register locations */
        !            18: #define PIC1_ICW1 0x20
        !            19: #define PIC1_OCW2 0x20
        !            20: #define PIC1_OCW3 0x20
        !            21: #define PIC1_ICR 0x20
        !            22: #define PIC1_IRR 0x20
        !            23: #define PIC1_ISR 0x20
        !            24: #define PIC1_ICW2 0x21
        !            25: #define PIC1_ICW3 0x21
        !            26: #define PIC1_ICW4 0x21
        !            27: #define PIC1_IMR 0x21
        !            28: #define PIC2_ICW1 0xa0
        !            29: #define PIC2_OCW2 0xa0
        !            30: #define PIC2_OCW3 0xa0
        !            31: #define PIC2_ICR 0xa0
        !            32: #define PIC2_IRR 0xa0
        !            33: #define PIC2_ISR 0xa0
        !            34: #define PIC2_ICW2 0xa1
        !            35: #define PIC2_ICW3 0xa1
        !            36: #define PIC2_ICW4 0xa1
        !            37: #define PIC2_IMR 0xa1
        !            38: 
        !            39: /* Register command values */
        !            40: #define OCW3_ID 0x08
        !            41: #define OCW3_READ_IRR 0x03
        !            42: #define OCW3_READ_ISR 0x02
        !            43: #define ICR_EOI_NON_SPECIFIC 0x20
        !            44: #define ICR_EOI_NOP 0x40
        !            45: #define ICR_EOI_SPECIFIC 0x60
        !            46: #define ICR_EOI_SET_PRIORITY 0xc0
        !            47: 
        !            48: /* Macros to enable/disable IRQs */
        !            49: #define IMR_REG(x) ( (x) < IRQ_PIC_CUTOFF ? PIC1_IMR : PIC2_IMR )
        !            50: #define IMR_BIT(x) ( 1 << ( (x) % IRQ_PIC_CUTOFF ) )
        !            51: #define irq_enabled(x) ( ( inb ( IMR_REG(x) ) & IMR_BIT(x) ) == 0 )
        !            52: #define enable_irq(x) outb ( inb( IMR_REG(x) ) & ~IMR_BIT(x), IMR_REG(x) )
        !            53: #define disable_irq(x) outb ( inb( IMR_REG(x) ) | IMR_BIT(x), IMR_REG(x) )
        !            54: 
        !            55: /* Macros for acknowledging IRQs */
        !            56: #define ICR_REG( irq ) ( (irq) < IRQ_PIC_CUTOFF ? PIC1_ICR : PIC2_ICR )
        !            57: #define ICR_VALUE( irq ) ( (irq) % IRQ_PIC_CUTOFF )
        !            58: #define CHAINED_IRQ 2
        !            59: 
        !            60: /* Utility macros to convert IRQ numbers to INT numbers and INT vectors  */
        !            61: #define IRQ_INT( irq ) ( ( ( (irq) - IRQ_PIC_CUTOFF ) ^ 0x70 ) & 0x7f )
        !            62: 
        !            63: /* Other constants */
        !            64: #define IRQ_MAX 15
        !            65: #define IRQ_NONE -1U
        !            66: 
        !            67: /* Function prototypes
        !            68:  */
        !            69: void send_eoi ( unsigned int irq );
        !            70: 
        !            71: #endif /* PIC8259_H */

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