Emulation/switch-coreboot
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added the support for the (IDIOTIC) 8259a. We're having trouble in some cases

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because we're not setting up the emulated hardware from Long, Long Ago
This commit is contained in:
Ronald G. Minnich 2000-11-20 04:30:00 +00:00
parent 29e4d00002
commit db69e90633
2 changed files with 55 additions and 0 deletions
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1
romimages/RON_VIA_SPD/crt0.S
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@ -29,6 +29,7 @@
#include <southbridge/via/vt82c686/setup_serial.inc>
#include <pc80/serial.inc>
#include <pc80/i8259.inc>
TTYS0_TX_STRING($ttyS0_test)

54
src/pc80/i8259.inc Normal file
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@ -0,0 +1,54 @@
/* code taken from:
!
! setup.S Copyright (C) 1991, 1992 Linus Torvalds
!
! setup.s is responsible for getting the system data from the BIOS,
! and putting them into the appropriate places in system memory.
! both setup.s and system has been loaded by the bootblock.
*/
/* we're getting screwed again and again by this problem of the 8259.
* so we're going to leave this lying around for inclusion into
* crt0.S on an as-needed basis.
! well, that went ok, I hope. Now we have to reprogram the interrupts :-(
! we put them right after the intel-reserved hardware interrupts, at
! int 0x20-0x2F. There they won't mess up anything. Sadly IBM really
! messed this up with the original PC, and they haven't been able to
! rectify it afterwards. Thus the bios puts interrupts at 0x08-0x0f,
! which is used for the internal hardware interrupts as well. We just
! have to reprogram the 8259's, and it isn't fun.
*/
#define i8259delay jmp 1f ; 1:
movb $0x11,%al /*! initialization sequence*/
outb %al,$0x20 /*! send it to 8259A-1*/
i8259delay
outb %al,$0xA0 /*! and to 8259A-2*/
i8259delay
movb $0x20,%al /*! start of hardware int's (0x20)*/
outb %al,$0x21
i8259delay
movb $0x28,%al /*! start of hardware int's 2 (0x28)*/
outb %al,$0xA1
i8259delay
movb $0x04,%al /*! 8259-1 is master*/
outb %al,$0x21
i8259delay
movb $0x02,%al /*! 8259-2 is slave*/
outb %al,$0xA1
i8259delay
movb $0x01,%al /*! 8086 mode for both*/
outb %al,$0x21
i8259delay
outb %al,$0xA1
i8259delay
movb $0xFF,%al /*! mask off all interrupts for now*/
outb %al,$0xA1
i8259delay
movb $0xFB,%al /*! mask all irq's but irq2 which*/
outb %al,$0x21 /*! is cascaded*/
/*
* I like the way Linus says it:
! Well, that certainly wasn't fun :-(. Hopefully it works, and we don't
! need no steenking BIOS anyway (except for the initial loading :-).
*/