/*
* Copyright (C) 2003-2004 Jakub Jermar
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <arch.h>
#include <arch/cp0.h>
#include <arch/exception.h>
#include <arch/asm/regname.h>
#include <arch/asm.h>
#include <mm/vm.h>
#include <userspace.h>
#include <arch/console.h>
#include <memstr.h>
#include <arch/interrupt.h>
/* Size of the code jumping to the exception handler code
* - J+NOP
*/
#define EXCEPTION_JUMP_SIZE 8
#define TLB_EXC ((char *) 0x80000000)
#define NORM_EXC ((char *) 0x80000180)
#define CACHE_EXC ((char *) 0x80000100)
#include <arch/debug.h>
#include <print.h>
void arch_pre_mm_init(void)
{
/* It is not assumed by default */
cpu_priority_high();
/* Copy the exception vectors to the right places */
memcpy(TLB_EXC
, (char *)tlb_refill_entry
, EXCEPTION_JUMP_SIZE
);
memcpy(NORM_EXC
, (char *)exception_entry
, EXCEPTION_JUMP_SIZE
);
memcpy(CACHE_EXC
, (char *)cache_error_entry
, EXCEPTION_JUMP_SIZE
);
/*
* Switch to BEV normal level so that exception vectors point to the kernel.
* Clear the error level.
*/
cp0_status_write(cp0_status_read() & ~(cp0_status_bev_bootstrap_bit|cp0_status_erl_error_bit));
/*
* Mask all interrupts
*/
cp0_mask_all_int();
/*
* Unmask hardware clock interrupt.
*/
cp0_unmask_int(TIMER_INTERRUPT);
/*
* Start hardware clock.
*/
cp0_compare_write(cp0_compare_value + cp0_count_read());
console_init();
}
void arch_post_mm_init(void)
{
}
void arch_late_init(void)
{
}
void userspace(void)
{
/* EXL=1, UM=1, IE=1 */
cp0_status_write(cp0_status_read() | (cp0_status_exl_exception_bit |
cp0_status_um_bit |
cp0_status_ie_enabled_bit));
cp0_epc_write(UTEXT_ADDRESS);
userspace_asm(USTACK_ADDRESS+PAGE_SIZE);
while (1)
;
}
/* Stack pointer saved when entering user mode */
/* TODO: How do we do it on SMP system???? */
__address supervisor_sp;
void before_thread_runs_arch(void)
{
supervisor_sp = (__address) &THREAD->kstack[THREAD_STACK_SIZE-SP_DELTA];
}