2004-10-15 00:44:26 +02:00
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#include <arch/io.h>
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2009-01-20 22:38:17 +01:00
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#include <pc80/i8259.h>
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2004-10-15 00:44:26 +02:00
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/* code taken from:
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!
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! setup.S Copyright (C) 1991, 1992 Linus Torvalds
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!
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! setup.s is responsible for getting the system data from the BIOS,
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! and putting them into the appropriate places in system memory.
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! both setup.s and system has been loaded by the bootblock.
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*/
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/* we're getting screwed again and again by this problem of the 8259.
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* so we're going to leave this lying around for inclusion into
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* crt0.S on an as-needed basis.
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! well, that went ok, I hope. Now we have to reprogram the interrupts :-(
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! we put them right after the intel-reserved hardware interrupts, at
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! int 0x20-0x2F. There they won't mess up anything. Sadly IBM really
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! messed this up with the original PC, and they haven't been able to
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! rectify it afterwards. Thus the bios puts interrupts at 0x08-0x0f,
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! which is used for the internal hardware interrupts as well. We just
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! have to reprogram the 8259's, and it isn't fun.
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*/
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void setup_i8259(void)
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{
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outb(0x11, 0x20); /*! initialization sequence to 8259A-1*/
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outb(0x11, 0xA0); /*! and to 8259A-2*/
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outb(0x20, 0x21); /*! start of hardware int's (0x20)*/
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outb(0x28, 0xA1); /*! start of hardware int's 2 (0x28)*/
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outb(0x04, 0x21); /*! 8259-1 is master*/
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outb(0x02, 0xA1); /*! 8259-2 is slave*/
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outb(0x01, 0x21); /*! 8086 mode for both*/
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outb(0x01, 0xA1);
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outb(0xFF, 0xA1); /*! mask off all interrupts for now*/
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outb(0xFB, 0x21); /*! mask all irq's but irq2 which is cascaded*/
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}
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/*
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* I like the way Linus says it:
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! Well, that certainly wasn't fun :-(. Hopefully it works, and we don't
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! need no steenking BIOS anyway (except for the initial loading :-).
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*/
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