/****************************************************************************
OS/A65 Version 2.0.0
Multitasking Operating System for 6502 Computers
Copyright (C) 1989-1998 Andre Fachat
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
****************************************************************************/
/***************************************************************************
*
* This file is included in the RESET routine of the kernel,
* after the "sei:cld". The routine starting at the bginning
* of this file must initialize the hardware to the system RAM
* in the beginning and the system ROM in the end of the memory
* map. Also the system stack (pointer) is setup.
*
* In addition to that the system interrupt timer (needed for
* task preemtion) must be setup.
*
* After that the file must define the following macros:
*
* GETFREQ() returns a=0 for 1Mhz, a=128 for 2MHz
* LEDPORT address of LED port to signal hardware failures
* LED_LED bit of LED bit in LEDPORT address
* H_ERROR() if LEDPORT is not defined, then H_ERROR replaces
* the LED toggle routine if needed.
* CLRTIMER() clear the system interrupt timer interrupt
* KERNELIRQ() returns if an interrupt occured in the kernel
* or outside. Is checked by "BNE IRQ_in_Kernel"
* SAVEMEM() save system mem config for interrupt
* RESTOREMEM() restore system mem config after interrupt
* STARTMEM() This is used to alloc/enable memory pages found
* during kernel init. Takes mem size in AC as given
* by the kernel init. It is called _after_ inimem!
*/
/* Kernel routines for C64 hardware */
/*
* init stack pointer for system stack
*/
ldx #<-1
txs
/*
* init memory configuration
*/
/* check if it's really a 8x96 */
lda #%10001100 ; memory config plain bank 1
sta $fff0 ; no I/O and screen peek through (prg bank)
ldx #11
ll0 lda eok_addr,x ; set interrupt etc vectors
sta $fff4,x
dex
bpl ll0
lda #%11100000 ; memory config plain bank 0
sta $fff0 ; I/O and screen peek through (system bank)
ldx #11
ll1 lda eok_addr,x ; set interrupt etc vectors
sta $fff4,x
dex
bpl ll1
/*
* C64 specific irq timer init, irq every 20ms
* We assume that the reset - or a loader program has disabled all irq
*/
lda #%00000001 ; enable PIA1 CB1 screen retrace timer
sta PETPIA1+PIA_CRA
/*
* check zeropage RAM, jump to he_zero if failure
* clears zeropage - at least 2-7 is a _must_!
*/
#include "kernel/zerotest.a65"
/*
* check system RAM from RAMSTAT up to RAMEND, jump to he_ram if failure
* returns available RAM in 256 byte blocks in AC
*/
.zero
cnt .byt 0
.text
#include "kernel/ramtest.a65"
cmp #MIN_MEM
bcs ok
lda #0
sta $fff0
jmp ($fffc)
ok
/*
* originally SYSPORT specific, they have a value for the C64 also...
*/
#define GETFREQ() lda #0
#undef LEDPORT
#undef LED_LED
/*
* We have to clear the interrupt timer
*/
#define CLRTIMER() lda PETPIA1+PIA_PA
/*
* MMU systems may map task pages into kernel mem to make copying
* easier. This mapping has to be preserved during interrupt.
* SAVEMEM() saves the memory configuration, while RESTOREMEM()
* restores it, obviously.
* These routines are called _after_ "jsr memsys", so this routine
* has to preserve this mapping when called from kernel space,
* and so must memtask.
*/
#undef SAVEMEM
#undef RESTOREMEM
/*
* Check if we have an interrupt in the kernel
*/
#define KERNELIRQ() lda Syscnt:cmp #1
/*
* no memory management...
*/
#define STARTMEM()
