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//========================================================================
//
//      pmon.S
//
//      Low-level entry points into PMON monitor.
//
//========================================================================
//####ECOSGPLCOPYRIGHTBEGIN####
// -------------------------------------------
// This file is part of eCos, the Embedded Configurable Operating System.
// Copyright (C) 1998, 1999, 2000, 2001, 2002 Red Hat, Inc.
//
// eCos 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 or (at your option) any later version.
//
// eCos 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 eCos; if not, write to the Free Software Foundation, Inc.,
// 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
//
// As a special exception, if other files instantiate templates or use macros
// or inline functions from this file, or you compile this file and link it
// with other works to produce a work based on this file, this file does not
// by itself cause the resulting work to be covered by the GNU General Public
// License. However the source code for this file must still be made available
// in accordance with section (3) of the GNU General Public License.
//
// This exception does not invalidate any other reasons why a work based on
// this file might be covered by the GNU General Public License.
//
// Alternative licenses for eCos may be arranged by contacting Red Hat, Inc.
// at http://sources.redhat.com/ecos/ecos-license/
// -------------------------------------------
//####ECOSGPLCOPYRIGHTEND####
//========================================================================
//#####DESCRIPTIONBEGIN####
//
// Author(s):     Red Hat, nickg
// Contributors:  Red Hat, nickg
// Date:          1999-04-21
// Purpose:       
// Description:   Low-level entry points into PMON monitor.
// Usage:         
//
//####DESCRIPTIONEND####
//
//========================================================================


#ifdef __mips16
/* This file contains 32 bit assembly code.  */
        .set nomips16
#endif

#if __mips < 3
  /* This machine does not support 64-bit operations.  */
  #define ADDU addu
  #define SUBU subu
#else
  /* This machine supports 64-bit operations.  */
  #define ADDU daddu
  #define SUBU dsubu
#endif


/* Standard MIPS register names: */
#define zero    $0
#define z0      $0
#define v0      $2
#define v1      $3
#define a0      $4
#define a1      $5
#define a2      $6
#define a3      $7
#define t0      $8
#define t1      $9
#define t2      $10
#define t3      $11
#define t4      $12
#define t5      $13
#define t6      $14
#define t7      $15
#define s0      $16
#define s1      $17
#define s2      $18
#define s3      $19
#define s4      $20
#define s5      $21
#define s6      $22
#define s7      $23
#define t8      $24
#define t9      $25
#define k0      $26     /* kernel private register 0 */
#define k1      $27     /* kernel private register 1 */
#define gp      $28     /* global data pointer */
#define sp      $29     /* stack-pointer */
#define fp      $30     /* frame-pointer */
#define ra      $31     /* return address */
#define pc      $pc     /* pc, used on mips16 */

#define fp0     $f0
#define fp1     $f1

/* Useful memory constants: */
#define K0BASE          0x80000000
#ifndef __mips64
#define K1BASE          0xA0000000
#else
#define K1BASE          0xFFFFFFFFA0000000LL
#endif

#define PHYS_TO_K1(a)   ((unsigned)(a) | K1BASE)

/* Standard Co-Processor 0 register numbers: */
#define C0_COUNT        $9              /* Count Register */
#define C0_SR           $12             /* Status Register */
#define C0_CAUSE        $13             /* last exception description */
#define C0_EPC          $14             /* Exception error address */
#define C0_CONFIG       $16             /* CPU configuration */

/* Standard Status Register bitmasks: */
#define SR_CU1          0x20000000      /* Mark CP1 as usable */
#define SR_FR           0x04000000      /* Enable MIPS III FP registers */
#define SR_BEV          0x00400000      /* Controls location of exception vectors */
#define SR_PE           0x00100000      /* Mark soft reset (clear parity error) */

#define SR_KX           0x00000080      /* Kernel extended addressing enabled */
#define SR_SX           0x00000040      /* Supervisor extended addressing enabled */
#define SR_UX           0x00000020      /* User extended addressing enabled */

/* Standard (R4000) cache operations. Taken from "MIPS R4000
   Microprocessor User's Manual" 2nd edition: */

#define CACHE_I         (0)     /* primary instruction */
#define CACHE_D         (1)     /* primary data */
#define CACHE_SI        (2)     /* secondary instruction */
#define CACHE_SD        (3)     /* secondary data (or combined instruction/data) */

#define INDEX_INVALIDATE                (0)     /* also encodes WRITEBACK if CACHE_D or CACHE_SD */
#define INDEX_LOAD_TAG                  (1)
#define INDEX_STORE_TAG                 (2)
#define CREATE_DIRTY_EXCLUSIVE          (3)     /* CACHE_D and CACHE_SD only */
#define HIT_INVALIDATE                  (4)
#define CACHE_FILL                      (5)     /* CACHE_I only */
#define HIT_WRITEBACK_INVALIDATE        (5)     /* CACHE_D and CACHE_SD only */
#define HIT_WRITEBACK                   (6)     /* CACHE_I, CACHE_D and CACHE_SD only */
#define HIT_SET_VIRTUAL                 (7)     /* CACHE_SI and CACHE_SD only */

#define BUILD_CACHE_OP(o,c)             (((o) << 2) | (c))

/* Individual cache operations: */
#define INDEX_INVALIDATE_I              BUILD_CACHE_OP(INDEX_INVALIDATE,CACHE_I)
#define INDEX_WRITEBACK_INVALIDATE_D    BUILD_CACHE_OP(INDEX_INVALIDATE,CACHE_D)
#define INDEX_INVALIDATE_SI             BUILD_CACHE_OP(INDEX_INVALIDATE,CACHE_SI)
#define INDEX_WRITEBACK_INVALIDATE_SD   BUILD_CACHE_OP(INDEX_INVALIDATE,CACHE_SD)

#define INDEX_LOAD_TAG_I                BUILD_CACHE_OP(INDEX_LOAD_TAG,CACHE_I)
#define INDEX_LOAD_TAG_D                BUILD_CACHE_OP(INDEX_LOAD_TAG,CACHE_D)
#define INDEX_LOAD_TAG_SI               BUILD_CACHE_OP(INDEX_LOAD_TAG,CACHE_SI)
#define INDEX_LOAD_TAG_SD               BUILD_CACHE_OP(INDEX_LOAD_TAG,CACHE_SD)

#define INDEX_STORE_TAG_I               BUILD_CACHE_OP(INDEX_STORE_TAG,CACHE_I)
#define INDEX_STORE_TAG_D               BUILD_CACHE_OP(INDEX_STORE_TAG,CACHE_D)
#define INDEX_STORE_TAG_SI              BUILD_CACHE_OP(INDEX_STORE_TAG,CACHE_SI)
#define INDEX_STORE_TAG_SD              BUILD_CACHE_OP(INDEX_STORE_TAG,CACHE_SD)

#define CREATE_DIRTY_EXCLUSIVE_D        BUILD_CACHE_OP(CREATE_DIRTY_EXCLUSIVE,CACHE_D)
#define CREATE_DIRTY_EXCLUSIVE_SD       BUILD_CACHE_OP(CREATE_DIRTY_EXCLUSIVE,CACHE_SD)

#define HIT_INVALIDATE_I                BUILD_CACHE_OP(HIT_INVALIDATE,CACHE_I)
#define HIT_INVALIDATE_D                BUILD_CACHE_OP(HIT_INVALIDATE,CACHE_D)
#define HIT_INVALIDATE_SI               BUILD_CACHE_OP(HIT_INVALIDATE,CACHE_SI)
#define HIT_INVALIDATE_SD               BUILD_CACHE_OP(HIT_INVALIDATE,CACHE_SD)

#define CACHE_FILL_I                    BUILD_CACHE_OP(CACHE_FILL,CACHE_I)
#define HIT_WRITEBACK_INVALIDATE_D      BUILD_CACHE_OP(HIT_WRITEBACK_INVALIDATE,CACHE_D)
#define HIT_WRITEBACK_INVALIDATE_SD     BUILD_CACHE_OP(HIT_WRITEBACK_INVALIDATE,CACHE_SD)

#define HIT_WRITEBACK_I                 BUILD_CACHE_OP(HIT_WRITEBACK,CACHE_I)
#define HIT_WRITEBACK_D                 BUILD_CACHE_OP(HIT_WRITEBACK,CACHE_D)
#define HIT_WRITEBACK_SD                BUILD_CACHE_OP(HIT_WRITEBACK,CACHE_SD)

#define HIT_SET_VIRTUAL_SI              BUILD_CACHE_OP(HIT_SET_VIRTUAL,CACHE_SI)
#define HIT_SET_VIRTUAL_SD              BUILD_CACHE_OP(HIT_SET_VIRTUAL,CACHE_SD)

        .text
        .align  2

#ifdef LSI
  #define PMON_VECTOR 0xffffffffbfc00200
#else
  #define PMON_VECTOR 0xffffffffbfc00500
#endif

#ifndef __mips_eabi
/* Provide named functions for entry into the monitor: */
#define INDIRECT(name,index)                            \
        .globl  name;                                   \
        .ent    name;                                   \
        .set    noreorder;                              \
name:   la      $2,+(PMON_VECTOR+((index)*4));          \
        lw      $2,0($2);                               \
        j       $2;                                     \
        nop;                                            \
        .set    reorder;                                \
        .end    name

#else
#define INDIRECT(name,index)                            \
        .globl  name;                                   \
        .ent    name;                                   \
        .set    noreorder;                              \
name:   la      $2,+(PMON_VECTOR+((index)*4));          \
        lw      $2,0($2);                               \
        SUBU    sp,sp,0x40;                             \
        sd      ra,0x38(sp);                            \
        sd      fp,0x30(sp);                            \
        jal     $2;                                     \
        move    fp,sp;                                  \
        ld      ra,0x38(sp);                            \
        ld      fp,0x30(sp);                            \
        j       ra;                                     \
        ADDU    sp,sp,0x40;                             \
        .set    reorder;                                \
        .end    name
#endif


/* The following magic numbers are for the slots into the PMON monitor */
/* The first are used as the lo-level library run-time: */
INDIRECT(pmon_read,0)
INDIRECT(pmon_write,1)
INDIRECT(pmon_open,2)
INDIRECT(pmon_close,3)
/* The following are useful monitor routines: */
INDIRECT(pmon_ioctl,4)
INDIRECT(pmon_printf,5)
INDIRECT(pmon_vsprintf,6)
INDIRECT(pmon_ttctl,7)
INDIRECT(pmon_cliexit,8)
INDIRECT(pmon_getenv,9)
INDIRECT(pmon_onintr,10)
INDIRECT(pmon_flush_cache,11)
INDIRECT(pmon_exception,12)

/* The following routine is required by the "print()" function: */
        .globl  pmon_outbyte
        .ent    pmon_outbyte
        .set    noreorder
pmon_outbyte:
        subu    sp,sp,0x20      /* allocate stack space for string */
        sd      ra,0x18(sp)     /* stack return address */
        sd      fp,0x10(sp)     /* stack frame-pointer */
        move    fp,sp           /* take a copy of the stack pointer */
        /* We leave so much space on the stack for the string (16
           characters), since the call to mon_printf seems to corrupt
           the 8bytes at offset 8 into the string/stack. */
        sb      a0,0x00(sp)     /* character to print */
        sb      z0,0x01(sp)     /* NUL terminator */
        jal     pmon_printf     /* and output the string */
        move    a0,sp           /* take a copy of the string pointer {DELAY SLOT} */

        move    sp,fp           /* recover stack pointer */
        ld      ra,0x18(sp)     /* recover return address */
        ld      fp,0x10(sp)     /* recover frame-pointer */
        j       ra              /* return to the caller */
        addu    sp,sp,0x20      /* dump the stack space {DELAY SLOT} */
        .set    reorder
        .end    pmon_outbyte
        
/* EOF pmon.S */