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/*
        Exception test.

        The following list outlines the tests performed
        
        Execption test
        - 0x100 reset                        - start addr after reset 
        - 0x200 bus error                    - unimplemented addr is accessed
        - 0x300 data page fault              - NOT tested here 
        - 0x400 instruction page fault       - NOT tested here 
        - 0x500 tick timer                   - NOT tested here 
        - 0x600 alignment                    - write to unaligned addr
        - 0x700 illegal instruction          - use unimplemented inst. l.div 
        - 0x800 external interrupt           - int triggered from wb slave 
        - 0x900 d-tlb miss                   - translation tests
        - 0xA00 i-tlb miss                   - NOT tested here 
        - 0xB00 range                        - NOT tested here 
        - 0xC00 system call                  - NOT tested here 
        - 0xD00 floating point               - NOT tested here 
        - 0xE00 trap                         - NOT tested here 
        - 0xF00 RESERVED 
        
        r11 - 1st exception counter incremented inside exception 
        r12 - 2nd exception counter incremented outside and rigth after
              exception
        ... other register use to be documented...

        Julius Baxter, julius@opencores.org
        Tadej Markovic, tadej@opencores.org
        
*/
//////////////////////////////////////////////////////////////////////
////                                                              ////
//// Copyright (C) 2010 Authors and OPENCORES.ORG                 ////
////                                                              ////
//// This source file may be used and distributed without         ////
//// restriction provided that this copyright statement is not    ////
//// removed from the file and that any derivative work contains  ////
//// the original copyright notice and the associated disclaimer. ////
////                                                              ////
//// This source file is free software; you can redistribute it   ////
//// and/or modify it under the terms of the GNU Lesser General   ////
//// Public License as published by the Free Software Foundation; ////
//// either version 2.1 of the License, or (at your option) any   ////
//// later version.                                               ////
////                                                              ////
//// This source 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 Lesser General Public License for more ////
//// details.                                                     ////
////                                                              ////
//// You should have received a copy of the GNU Lesser General    ////
//// Public License along with this source; if not, download it   ////
//// from http://www.opencores.org/lgpl.shtml                     ////
////                                                              ////
//////////////////////////////////////////////////////////////////////

#include "spr-defs.h"
#include "board.h"
#include "or1200-defines.h"
        
/* =================================================== [ exceptions ] === */
        .section .vectors, "ax"


/* ---[ 0x100: RESET exception ]----------------------------------------- */
        .org 0x100      
        l.movhi r0, 0
        /* Clear status register */
        l.ori   r1, r0, SPR_SR_SM
        l.mtspr r0, r1, SPR_SR
        /* Clear timer  */
        l.mtspr r0, r0, SPR_TTMR
        /* Init the stack */
        .global stack
        l.movhi r1, hi(stack)
        l.ori   r1, r1, lo(stack)
        l.addi  r2, r0, -3
        l.and   r1, r1, r2
        /* Jump to program initialisation code */
        .global _start
        l.movhi r4, hi(_start)
        l.ori   r4, r4, lo(_start)
        l.jr    r4
        l.nop

  
/* ---[ 0x200: BUS error ]------------------------------------------------ */
        .org 0x200
        .global _bus_handler
_bus_handler:   
        l.mfspr r3,r0,SPR_EPCR_BASE     /* Get EPC */
        l.nop   2
        l.mfspr r3,r0,SPR_EEAR_BASE     /* Get EEA */
        l.nop   2
        l.addi  r11,r11,1               /* Increment 1st exception counter */
        l.sfeqi r2, 0xd /* Is this a data bus test, if so return with l.rfe */
        l.bf 1f
        l.movhi r5, 0    /* r5 should be the one causing the error on dbus */
        /* Instruction bus error test return */
        l.movhi r5, hi(0x44004800) /* Put "l.jr r9" instruction in r5 */
        l.ori r5, r5, lo(0x44004800)
        l.sw 0x0(r0), r5 /* Write "l.j r9" to address 0x0 in RAM */
        l.movhi r5,0x1500       /* Put a "l.nop"  instruction in r5 */
        l.sw    0x4(r0),r5      /* Write l.nop instruction to RAM addr 0x4 */
        l.mtspr r0,r0,SPR_ICBIR         /* Invalidate line 0 of cache */
        l.mtspr r0,r0,SPR_EPCR_BASE     /* RFE to 0x0, which is l.jr r9 */
1:      l.rfe

/* ---[ 0x600: ALIGN error ]------------------------------------------------ */
        .org 0x600
        .global _align_handler
_align_handler: 
        l.mfspr r3,r0,SPR_EPCR_BASE     /* Get EPC */
        l.nop   2
        l.addi  r11,r11,1               /* Increment 1st exception counter */
        l.movhi r5,0                    /* Clear the pointer register */
        l.rfe


/* ---[ 0x700: ILLEGAL INSN exception ]------------------------------------- */
        .org 0x700
        .global _illinsn_handler
_illinsn_handler:
        l.mfspr r3,r0,SPR_EPCR_BASE     /* Get EPC */
        l.nop   2
        l.addi  r11,r11,1               /* Increment 1st exception counter */
        /* Delay slot test needs this instruction "fixed" */
        l.movhi r5,0x1500               /* Put a "l.nop"  instruction in r5 */
        l.sw    0x4(r0),r5      /* Write l.nop instruction to RAM addr 0x4 */
        l.mtspr r0,r0,SPR_ICBIR         /* Invalidate line 0 of cache */
        l.mtspr r0,r0,SPR_EPCR_BASE     /* Jump to 0, which is l.jr r9 */
        l.rfe

/* ---[ 0x900: DTLB exception ]--------------------------------------------- */
        .org 0x900
        .global _dtlb_handler
/* Exception handler - DMMU TLB miss */
/* Assume 64-entry TLB cache */ 
_dtlb_handler:
        l.sw    -4(r1),r4
        l.sw    -8(r1),r5
        l.sw    -12(r1),r6
        l.sw    -16(r1),r7
        l.sw    -20(r1),r8
        l.mfspr r2, r0, SPR_EEAR_BASE
        /* Find the entry/set for this address */
        l.srli r13, r2, 13 /* r13 = VPN, shift by size 8192 = 2**13 */
        l.andi r4, r13, 0x3f /* 64 entries = 6 bit mask, r4 = set number */
        /* If page is in the 0xc0000000 space we map to 4MB part of
        memory, ie 0x0 => 0x00400000, otherwise 1-1 mapping */
        l.movhi r5, hi(0xc0000000)
        l.ori r5, r5, lo(0xc0000000)
        l.srli r5, r5, 13 /* Get page address, shift by page size, 13 bits */
        l.movhi r6, hi(0xff << 11) /* Mask for top byte of VPN */
        l.ori r6, r6, lo(0xff << 11)
        l.and r6, r6, r13 /* Mask in only top byte of VPN */
        l.sfeq r5, r6 /* Decide if it's in our special mapped region or not*/
        
        /* First, Setup value for DTLBM (match) reg, is same for both cases */
        l.movhi r6, hi(SPR_ITLBMR_VPN) /* VPN mask into r6 */
        l.ori r6, r6, lo(SPR_ITLBMR_VPN)
        l.and r7, r2, r6 /* AND address with VPN mask */
        l.ori r7, r7, SPR_DTLBMR_V /* OR in valid bit */
        l.mtspr r4, r7, SPR_DTLBMR_BASE(0) /* Write to DTLBR register */

        l.bf _highmem_map
        l.nop
        
_lomem_map:
        /* Do 1:1 mapping for this request */
        /* Setup value for translate register */
        l.movhi r6, hi(SPR_ITLBTR_PPN) /* PPN mask into r6 */
        l.ori r6, r6, lo(SPR_ITLBTR_PPN)
        l.and r7, r2, r6 /* AND address with PPN mask */
        l.ori r7, r7, DTLB_PR_NOLIMIT /* Set all execute enables, no lims. */
        l.mtspr r4, r7, SPR_DTLBTR_BASE(0) /* Write to DTLTR register */
        l.j _dtlb_done
        l.addi r14, r14, 1 /* Incremement low-mapping counter */

_highmem_map:
        /* Do top byte, 0xc00->0x004, mapping for this request */
        /* Setup value for translate register */
        l.movhi r6, hi(SPR_ITLBTR_PPN) /* PPN mask into r6 */
        l.ori r6, r6, lo(SPR_ITLBTR_PPN)
        l.and r7, r2, r6 /* AND address with PPN mask */
        l.movhi r8, hi(0xffff0000) /* Top byte address mask */
        l.or r7, r8, r7 /* Set top byte to 0xff */
        l.xor r7, r8, r7 /* Now clear top byte with XOR */
        l.movhi r8, hi(0x00400000) /* Top address byte */
        l.or r7, r8, r7 /* Set top address byte */
        l.ori r7, r7, DTLB_PR_NOLIMIT /* Set all execute enables, no lims. */
        l.mtspr r4, r7, SPR_DTLBTR_BASE(0) /* Write to DTLTR register */
        l.addi r15, r15, 1 /* Incremement low-mapping counter */
        
_dtlb_done:
        l.lwz   r4,-4(r1)
        l.lwz   r5,-8(r1)
        l.lwz   r6,-12(r1)
        l.lwz   r7,-16(r1)
        l.lwz   r8,-20(r1)
        l.rfe



/* =================================================== [ text section ] === */
        .section  .text

/* =================================================== [ start ] === */ 

        .global _start
_start: 
        l.jal   _cache_init
        l.nop
        // Kick off test
        l.jal   _main
        l.nop

/* ========================================================= [ main ] === */

        .global _main
        .global _dmmu_invalidate
        .global _dmmu_except1
        
_main:          
        l.nop   
        l.addi  r3,r0,0
        l.addi  r5,r0,0
        l.addi  r11,r0,0 /* exception counter 1 */
        l.addi  r12,r0,0 /* exception counter 2 */
        l.addi  r13,r0,0
        l.addi  r14,r0,0 /* DMMU exception counter for low mem mapping */
        l.addi  r15,r0,0 /* DMMU exception counter for hi mem mapping */
        l.sw    0x0(r0),r0      /* Initialize RAM */    
        l.sw    0x4(r0),r0      /* Initialize RAM */    
        l.sw    0x8(r0),r0      /* Initialize RAM */    
        l.sw    0xc(r0),r0      /* Initialize RAM */    
        l.sw    0x10(r0),r0     /* Initialize RAM */    
        l.sw    0x14(r0),r0     /* Initialize RAM */    
        l.sw    0x18(r0),r0     /* Initialize RAM */    
        l.sw    0x1c(r0),r0     /* Initialize RAM */    
        l.sw    0x20(r0),r0     /* Initialize RAM */    
        l.sw    0x24(r0),r0     /* Initialize RAM */    
        l.sw    0x28(r0),r0     /* Initialize RAM */    
        l.sw    0x2c(r0),r0     /* Initialize RAM */    
        l.sw    0x30(r0),r0     /* Initialize RAM */    
        l.sw    0x34(r0),r0     /* Initialize RAM */    
        l.sw    0x38(r0),r0     /* Initialize RAM */    
        l.sw    0x3c(r0),r0     /* Initialize RAM */    
        l.sw    0x40(r0),r0     /* Initialize RAM */    
        l.sw    0x44(r0),r0     /* Initialize RAM */    
        l.sw    0x48(r0),r0     /* Initialize RAM */    
        l.sw    0x4c(r0),r0     /* Initialize RAM */    
        l.j     _align1
        //l.j _dmmu_except1
        l.nop


        /* Exceptions followed by NOPs */

        /* SW alignment exception */
_align1:        
        l.movhi r11,0
        l.nop
        /* Test l.sh */
        l.ori r5,r0,0x1 /* Half-word access, offset 1 */
        l.sh 0x0(r5),r0
        l.addi r12,r12,1 /* Increment 2nd exception counter */
        l.ori r5,r0,0x3 /* Half-word access, offset 3 */
        l.sh 0x0(r5),r0
        l.addi r12,r12,1 /* Increment 2nd exception counter */
        /* Test l.lhz */
        l.ori r5,r0,0x1 /* Half-word access, offset 1 */
        l.lhz r3,0x0(r5)
        l.addi r12,r12,1 /* Increment 2nd exception counter */
        l.ori r5,r0,0x3 /* Half-word access, offset 3 */
        l.lhz r3,0x0(r5)
        l.addi r12,r12,1 /* Increment 2nd exception counter */
        /* Test l.lhs */
        l.ori r5,r0,0x1 /* Half-word access, offset 1 */
        l.lhs r3,0x0(r5)
        l.addi r12,r12,1 /* Increment 2nd exception counter */
        l.ori r5,r0,0x3 /* Half-word access, offset 3 */
        l.lhs r3,0x0(r5)        
        l.addi r12,r12,1 /* Increment 2nd exception counter */
        /* Test l.sw */
        l.ori r5,r0,0x1 /* Word access, offset 1 */     
        l.sw 0x0(r5), r0
        l.addi r12,r12,1 /* Increment 2nd exception counter */
        l.ori r5,r0,0x2 /* Word access, offset 2 */     
        l.sw 0x0(r5), r0
        l.addi r12,r12,1 /* Increment 2nd exception counter */
        l.ori r5,r0,0x3 /* Word access, offset 3 */     
        l.sw 0x0(r5), r0
        l.addi r12,r12,1 /* Increment 2nd exception counter */
        /* Test l.lwz */
        l.ori r5,r0,0x1 /* Word access, offset 1 */     
        l.lwz r3,0x0(r5)
        l.addi r12,r12,1 /* Increment 2nd exception counter */
        l.ori r5,r0,0x2 /* Word access, offset 2 */     
        l.lwz r3,0x0(r5)
        l.addi r12,r12,1 /* Increment 2nd exception counter */
        l.ori r5,r0,0x3 /* Word access, offset 3 */     
        l.lwz r3,0x0(r5)
        l.addi r12,r12,1 /* Increment 2nd exception counter */
#if OR1200_HAS_LWS==1   
        /* Test l.lws */
        l.ori r5,r0,0x1 /* Word access, offset 1 */     
        l.lws r3,0x0(r5)
        l.addi r12,r12,1 /* Increment 2nd exception counter */
        l.ori r5,r0,0x2 /* Word access, offset 2 */     
        l.lws r3,0x0(r5)
        l.addi r12,r12,1 /* Increment 2nd exception counter */
        l.ori r5,r0,0x3 /* Word access, offset 3 */     
        l.lws r3,0x0(r5)        
        l.addi r12,r12,1 /* Increment 2nd exception counter */
        l.nop
#endif  
        /* Now test them in delay slots */
        
        l.ori r5,r0,0x1 /* Half-word access, offset 1 */
        l.j 1f  
        l.sh 0x0(r5),r0
        l.nop
1:      l.addi r12,r12,1 /* Increment 2nd exception counter */
        l.ori r5,r0,0x3 /* Half-word access, offset 3 */
        l.j 2f          
        l.sh 0x0(r5),r0
        l.nop
2:      l.addi r12,r12,1 /* Increment 2nd exception counter */

        /* Test l.lhz */
        l.ori r5,r0,0x1 /* Half-word access, offset 1 */
        l.j 3f
        l.lhz r3,0x0(r5)
        l.nop
3:      l.addi r12,r12,1 /* Increment 2nd exception counter */
        l.ori r5,r0,0x3 /* Half-word access, offset 3 */
        l.j 4f
        l.lhz r3,0x0(r5)
        l.nop
4:      l.addi r12,r12,1 /* Increment 2nd exception counter */
        
        /* Test l.lhs */
        l.ori r5,r0,0x1 /* Half-word access, offset 1 */
        l.j 5f
        l.lhs r3,0x0(r5)
        l.nop
5:      l.addi r12,r12,1 /* Increment 2nd exception counter */
        l.ori r5,r0,0x3 /* Half-word access, offset 3 */
        l.j 6f
        l.lhs r3,0x0(r5)
        l.nop
6:      l.addi r12,r12,1 /* Increment 2nd exception counter */
        
        /* Test l.sw */
        l.ori   r5,r0,0x1 /* Word access, offset 1 */     
        l.j     7f
        l.sw    0x0(r5), r0
        l.nop   
7:      l.addi  r12,r12,1 /* Increment 2nd exception counter */
        l.ori   r5,r0,0x2 /* Word access, offset 2 */     
        l.j     8f
        l.sw    0x0(r5), r0
        l.nop   
8:      l.addi  r12,r12,1 /* Increment 2nd exception counter */
        l.ori   r5,r0,0x3 /* Word access, offset 3 */     
        l.j     9f
        l.sh    0x0(r5), r0
        l.nop
9:      l.addi  r12,r12,1 /* Increment 2nd exception counter */

        /* Test l.lwz */
        l.ori   r5,r0,0x1 /* Word access, offset 1 */
        l.j     10f
        l.lwz   r3,0x0(r5)
        l.nop
10:     l.addi  r12,r12,1 /* Increment 2nd exception counter */
        l.ori   r5,r0,0x2 /* Word access, offset 2 */
        l.j     11f
        l.lwz   r3,0x0(r5)
        l.nop
11:     l.addi  r12,r12,1 /* Increment 2nd exception counter */
        l.ori   r5,r0,0x3 /* Word access, offset 3 */
        l.j     12f
        l.lwz   r3,0x0(r5)
        l.nop
12:     l.addi  r12,r12,1 /* Increment 2nd exception counter */
#if OR1200_HAS_LWS==1
        /* Test l.lws */
        l.ori   r5,r0,0x1 /* Word access, offset 1 */
        l.j     13f
        l.lws   r3,0x0(r5)
        l.nop
13:     l.addi  r12,r12,1 /* Increment 2nd exception counter */
        l.ori   r5,r0,0x2 /* Word access, offset 2 */
        l.j     14f
        l.lws   r3,0x0(r5)
        l.nop
14:     l.addi  r12,r12,1 /* Increment 2nd exception counter */
        l.ori   r5,r0,0x3 /* Word access, offset 3 */
        l.j     15f
        l.lws   r3,0x0(r5)
        l.nop
15:     l.addi  r12,r12,1 /* Increment 2nd exception counter */
                
#endif
        /* Check 1st and 2nd exception counters are equal */
        l.sfeq  r11,r12                 /* Should be equal */
        l.bf    17f
        l.nop
        l.nop   1
17:     l.nop   2
        l.nop

        /* Illegal instruction exception */
_illegal1:      
        l.nop
        l.nop
        l.movhi r5, hi(0x44004800) /* Put "l.jr r9" instruction in r5 */
        l.ori   r5, r5, lo(0x44004800)
        l.sw    0x0(r0), r5     /* Write "l.j r9" to address 0x0 in RAM */      
        l.movhi r5, 0xee00      /* Put an illegal instruction in r5 */
        l.sw    0x4(r0), r5     /* Write illegal instruction to RAM addr 0x4 */
        l.movhi r5, 0x1500      /* l.nop after illegal instruction */
        l.sw    0x8(r0), r5     /* Write nop to RAM addr 0x8 */
        l.mtspr r0,r0,SPR_ICBIR /* Invalidate line 0 of cache */
        /* Jump to 0x4 - illegal opcode instruction */
        l.ori   r6, r0, 0x4
        l.jalr  r6              /* Jump to address 0x4, land on illegal insn */
        l.addi  r12,r12,1       /* Increment 2nd exception counter */
        l.nop                   /* Should return here */        
        l.nop

        /* Test in delay slot */
        
        l.movhi r5, 0xee00      /* Put an illegal instruction in r5 */
        l.sw    0x4(r0), r5     /* Write illegal instruction to RAM addr 0x4 */
        l.mtspr r0,r0,SPR_ICBIR /* Invalidate line 0 of cache */        
        l.jalr  r0 /* Jump to address 0, will be a jump back but with an illegal
                     dslot instruction which will befixed by handler */
        l.addi  r12,r12,1       /* Increment 2nd exception counter */
        l.nop                   /* Should return here */

        /* Check 1st and 2nd exception counters are equal */
        l.sfeq  r11,r12         /* Should be equal */
        l.bf    1f
        l.nop
        l.or    r3, r12, r12
        l.nop   2               /* Report expected exception count */
        l.or    r3, r11, r11
        l.nop   2               /* Report actual exception count */
        l.nop   1
1:      l.nop
        l.nop
        

_dbus1:
        l.nop
        l.movhi r12, 0 /* Reset exception counters */
        l.movhi r11, 0
        l.ori r2, r0, 0xd /* put 0xd in r2, indicate it's databus test */
        /* Cause access error */
        /* Load word */ 
        l.movhi r5, 0xee00 /* Address to cause an error */
        l.lwz r6, 0(r5) 
        l.addi r12, r12, 1 /* Incremement secondary exception counter */
        /* Load half */ 
        l.movhi r5, 0xee00 /* Address to cause an error */
        l.lhz r6, 0(r5)
        l.addi r12, r12, 1 /* Incremement secondary exception counter */
        /* Load byte */ 
        l.movhi r5, 0xee00 /* Address to cause an error */
        l.lbz r6, 0(r5)
        l.addi r12, r12, 1 /* Incremement secondary exception counter */
        /* Store word */        
        l.movhi r5, 0xee00 /* Address to cause an error */
        l.sw 0(r5), r6
        l.addi r12, r12, 1 /* Incremement secondary exception counter */
        /* Store half */        
        l.movhi r5, 0xee00 /* Address to cause an error */
        l.sh 0(r5), r6
        l.addi r12, r12, 1 /* Incremement secondary exception counter */
        /* Store byte */        
        l.movhi r5, 0xee00 /* Address to cause an error */
        l.sb 0(r5), r6
        l.addi r12, r12, 1 /* Incremement secondary exception counter */        
        l.nop
        /* Delay slot tests */
        /* Load word */ 
        l.movhi r5, 0xee00 /* Address to cause an error */      
        l.j 1f
        l.lwz r6, 0(r5) /* Data bus error in delay slot */
        l.nop
1:      l.addi r12, r12, 1
        /* Load half */
        l.movhi r5, 0xee00 /* Address to cause an error */      
        l.j 2f
        l.lhz r6, 0(r5) /* Data bus error in delay slot */
        l.nop
2:      l.addi r12, r12, 1      
        /* Load byte */
        l.movhi r5, 0xee00 /* Address to cause an error */      
        l.j 3f
        l.lbz r6, 0(r5) /* Data bus error in delay slot */
        l.nop
3:      l.addi r12, r12, 1      
        /* Store word */
        l.movhi r5, 0xee00 /* Address to cause an error */      
        l.j 4f
        l.sw 0(r5), r6  /* Data bus error in delay slot */
        l.nop
4:      l.addi r12, r12, 1      
        /* Store half */
        l.movhi r5, 0xee00 /* Address to cause an error */      
        l.j 5f
        l.sh 0(r5), r6  /* Data bus error in delay slot */
        l.nop
5:      l.addi r12, r12, 1      
        /* Store byte */
        l.movhi r5, 0xee00 /* Address to cause an error */      
        l.j 6f
        l.sb 0(r5), r6  /* Data bus error in delay slot */
        l.nop
6:      l.addi r12, r12, 1      


/* Check 1st and 2nd exception counters are equal */
        l.sfeq  r11,r12                 /* Should be equal */
        l.bf 7f
        l.nop
        l.or r3, r12, r12
        l.nop 2 /* Report expected exception count */
        l.or r3, r11, r11
        l.nop 2 /* Report actual exception count */
        l.nop 1
7:      l.nop

        
        
_ibus1:
        /* TODO: do this it with cache enabled/disabled */      
        l.movhi r12, 0 /* Reset exception counters */
        l.movhi r11, 0
        l.movhi r2, 0x0 /* put 0x0 in r2,indicate it's instruction bus test*/
        /* Cause access error */
        l.movhi r5, 0xee00 /* Address to cause an error */
        l.jalr r5 /* Jump and link to bad address */
        l.nop
        l.addi r12, r12, 1 /* Incremement secondary exception counter */
        /* Check 1st and 2nd exception counters are equal */
        l.sfeq  r11,r12                 /* Should be equal */
        l.bf 1f
        l.nop
        l.or r3, r12, r12
        l.nop 2 /* Report expected exception count */
        l.or r3, r11, r11
        l.nop 2 /* Report actual exception count */
        l.nop 1
1:      l.nop
        l.nop   

        
        /* Data MMU exception - try case where we need to translate address as
           we l.rfe to it */
        // Check the DMMU is the in the design, otherwise don't compile in this
        // test.
#ifndef OR1200_NO_DMMU  
        .extern lo_dmmu_en
_dmmu_except1:
        /* Call DMMU invalidate function */
        l.movhi r4, hi(_dmmu_invalidate)
        l.ori r4, r4, lo(_dmmu_invalidate)
        l.jalr r4
        l.ori r3, r0, 64 /* Put number of entries in r3 */

        l.movhi r5, hi(0x00400000)
        /* Write a word to the place where we'll translate to */
        l.movhi r7, hi(0xaabbccdd)
        l.ori r7, r7, lo(0xaabbccdd)
        l.sw 0(r5), r7 /* Shouldn't trigger MMU */
        l.sfne r14, r0
        l.bf _dmmu_test_error
        l.nop
        l.sfne r15, r0
        l.bf _dmmu_test_error
        l.nop
        
        /* Now enable DMMU */
        l.movhi r4, hi(lo_dmmu_en)
        l.ori r4, r4, lo(lo_dmmu_en)
        l.jalr r4
        l.nop

        /* Now start test. 0xc0000000 should go to 0x00400000 */
        l.lwz r8, 0(r5) /* Should cause DMMU miss, lomem */
        /* Check value was OK */
        l.sfne r7, r8
        l.bf _dmmu_test_error
        l.nop
        l.sfnei r14, 0x1 /* Check for lo mem mapping */
        l.bf _dmmu_test_error
        l.nop
        l.sfne r15, r0 /* hi-mem counter should still be 0 */
        l.bf _dmmu_test_error
        l.nop

        /* Test accesses to mapped area */
        l.movhi r6, hi(0xc0000000)
        l.lwz r8, 0(r6) /* Should cause DMMU miss, himem */
        /* Check value was OK */
        l.sfne r7, r8
        l.bf _dmmu_test_error
        l.nop
        l.sfnei r14, 0x1 /* Check for lo mem mapping */
        l.bf _dmmu_test_error
        l.nop
        l.sfnei r15, 0x1 /* hi-mem counter should still be 0 */
        l.bf _dmmu_test_error
        l.nop

        /* Now start test. 0xc0000000 should go to 0x00400000 */
        l.lwz r8, 0(r5) /* Should cause DMMU miss, lomem */
        /* Check value was OK */
        l.sfne r7, r8
        l.bf _dmmu_test_error
        l.nop
        l.sfnei r14, 0x2 /* Check for lo mem mapping increment */
        l.bf _dmmu_test_error
        l.nop
        l.sfnei r15, 0x1 /* hi-mem counter should still be 1 */
        l.bf _dmmu_test_error
        l.nop

        l.addi r7, r7, 0x1111 /* Incremement value we're writing */
        
        l.sw 4(r6), r7 /* Should cause DMMU miss, himem */      
        l.sfnei r14, 0x2 /* Check for lo mem mapping */
        l.bf _dmmu_test_error
        l.nop
        l.sfnei r15, 0x2 /* hi-mem counter should be 2 */
        l.bf _dmmu_test_error
        l.nop

        l.lwz r8, 4(r5) /* Should cause DMMU miss, lomem */
        /* Check value was OK */
        l.sfne r7, r8
        l.bf _dmmu_test_error
        l.nop
        l.sfnei r14, 0x3 /* Check for lo mem mapping increment */
        l.bf _dmmu_test_error
        l.nop
        l.sfnei r15, 0x2 /* hi-mem counter should still be 2 */
        l.bf _dmmu_test_error
        l.nop

        /* Fast DMMU exceptions should follow */
        l.addi r7, r7, 0x1111 /* Incremement value we're writing */
        l.sw 8(r6), r7 /* Should cause DMMU miss, himem */
        l.lwz r8, 8(r5) /* Should cause DMMU miss, lomem */
        l.addi r7, r7, 0x1111 /* Incremement value we're writing */
        l.sw 0xc(r6), r7 /* Should cause DMMU miss, himem */
        l.lwz r8, 0xc(r5) /* Should cause DMMU miss, lomem */
        l.addi r7, r7, 0x1111 /* Incremement value we're writing */
        l.sw 0x10(r6), r7 /* Should cause DMMU miss, himem */
        l.lwz r8, 0x10(r5) /* Should cause DMMU miss, lomem */
        l.addi r7, r7, 0x1111 /* Incremement value we're writing */
        l.sw 0x14(r6), r7 /* Should cause DMMU miss, himem */
        l.lwz r8, 0x14(r5) /* Should cause DMMU miss, lomem */
        l.addi r7, r7, 0x1111 /* Incremement value we're writing */
        l.sw 0x18(r6), r7 /* Should cause DMMU miss, himem */
        l.lwz r8, 0x18(r5) /* Should cause DMMU miss, lomem */
        l.addi r7, r7, 0x1111 /* Incremement value we're writing */
        l.sw 0x1c(r6), r7 /* Should cause DMMU miss, himem */
        l.lwz r8, 0x1c(r5) /* Should cause DMMU miss, lomem */
        l.addi r7, r7, 0x1111 /* Incremement value we're writing */
        l.sw 0x20(r6), r7 /* Should cause DMMU miss, himem */
        l.lwz r8, 0x20(r5) /* Should cause DMMU miss, lomem */
        l.addi r7, r7, 0x1111 /* Incremement value we're writing */
        l.sw 0x24(r6), r7 /* Should cause DMMU miss, himem */
        l.lwz r8, 0x24(r5) /* Should cause DMMU miss, lomem */
        /* Should now be 11 lowmem DTLB misses and 10 for high memory space */
        l.sfne r7, r8
        l.bf _dmmu_test_error
        l.nop
        l.sfnei r14, 0xb /* Check for lo mem mapping increment to 11 */
        l.bf _dmmu_test_error
        l.nop
        l.sfnei r15, 0xa /* hi-mem counter should be 10 */
        l.bf _dmmu_test_error
        l.nop
        
        l.j _dmmu_test_ok
        l.nop
        
        
_dmmu_test_error:
        l.movhi r3, hi(0xeeeeeeed)
        l.ori r3, r3, lo(0xeeeeeeed)
        l.nop 2
        l.nop 1

_dmmu_test_ok:
        l.nop
        
#endif // #ifndef OR1200_NO_DMMU
        
        /* End of tests - report and finish simulation */
        l.movhi r3,hi(0xdeaddead)
        l.ori   r3,r3,lo(0xdeaddead)
        l.nop   2

        l.movhi r3,hi(0x8000000d)
        l.ori   r3,r3,lo(0x8000000d)
        l.nop   2

        l.addi r3,r0,0
        l.jal   exit
        l.nop


        /* DMMU invalidate function */
        /* First parameter, r3, has number of DMMU entries (should be 64)*/

_dmmu_invalidate:
        /* Setup the Data MMU's TLBS */
        l.movhi r4, hi(SPR_DTLBMR_BASE(0))
        l.ori r4, r4, lo(SPR_DTLBMR_BASE(0))

        /* DTLB invalidate loop */
1:
        l.mtspr r4, r0, 0x0
        l.addi r4, r4, 0x1
        l.sfeq r3, r0
        l.bnf 1b
        l.addi r3, r3, -1
        l.jr r9
        l.nop