vectors.s

完整的Bell实验室的嵌入式文件系统TFS

    .file   "vectors.s"

/*  General notice:
 *  This code is part of a boot-monitor package developed as a generic base
 *  platform for embedded system designs.  As such, it is likely to be
 *  distributed to various projects beyond the control of the original
 *  author.  Please notify the author of any enhancements made or bugs found
 *  so that all may benefit from the changes.  In addition, notification back
 *  to the author will allow the new user to pick up changes that may have
 *  been made by other users after this version of the code was distributed.
 *
 *  Author: Ed Sutter
 *  email:  [e-mail]      (home: [e-mail])
 *  phone:  [phone]            (home: 908-889-5161)
 */


    .import _regtbl
    .import _exception
    .import _exceptionCause
    .import _MonStackEnd

    .globl  _resume
    .globl  _gotoexception

    .text

/*****************************************************************************
 * 
 * gotoexception:
 * When this code is executed as part of the exception processing,
 * it is assumed that R0 contains the vector number and the actual
 * value that was in R0 prior to the exception has been pushed onto
 * the stack.  
 * The general exception handling process within the monitor is that any
 * exception taken will cause some kind of entry into the monitor code
 * with the array regtbl[] filled with the CPU context at the time of the
 * exception.  When the monitor determines (either internally or through a
 * command issued by the user) that it is to return control to the application,
 * it calls resume() to load all of the registers with the values stored in
 * regtbl[].
 */
gotoexception:
    mov.l   r0,@-r15            /* Push R0 onto stack so that it can be used */
    mov.l   p_regtbl,r0         /* to point to the register store table. */
    mov.l   r1,@(4,r0)          /* Save R1 */
    mov.l   r2,@(8,r0)          /* Save R2 */
    mov.l   r3,@(12,r0)         /* Save R3 */
    mov.l   r4,@(16,r0)         /* Save R4 */
    mov.l   r5,@(20,r0)         /* Save R5 */
    mov.l   r6,@(24,r0)         /* Save R6 */
    mov.l   r7,@(28,r0)         /* Save R7 */
    mov.l   r8,@(32,r0)         /* Save R8 */
    mov.l   r9,@(36,r0)         /* Save R9 */
    mov.l   r10,@(40,r0)        /* Save R10 */
    mov.l   r11,@(44,r0)        /* Save R11 */
    mov.l   r12,@(48,r0)        /* Save R12 */
    mov.l   r13,@(52,r0)        /* Save R13 */
    mov.l   r14,@(56,r0)        /* Save R14 */

    mov.l   @r15+,r0            /* Pull vector number off stack and put it */
    mov.l   p_exceptionCause,r1 /* into the ExceptionCause variable. */
    mov.l   r0,@r1          

    mov.l   @r15+,r0            /* Pull R0 off stack and now use R1 to point */
    mov.l   p_regtbl,r1         /* to register store table. */
    mov.l   r0,@r1              /* Save R0 */
    mov.l   r15,@(60,r1)        /* Save R15 */
    mov.l   @r15,r0             /* Pull PC off stack and put it in register */
    add     #64,r1              /* store table. */
    mov.l   r0,@r1
    mov.l   @(4,r15),r0         /* Pull SR off stack and put it in register */
    add     #4,r1               /* store table. */
    mov.l   r0,@r1
    add     #4,r1               /* Save PR */
    sts     pr,r8
    mov.l   r8,@r1
    mov.l   p_MonStackEnd,r8    /* Load the monitor's stack poniter. */
    mov.l   @r8,r15
    mov.l   p_exception,r8      /* Jump to C-level exception handler. */
    jmp     @r8
    nop

/*****************************************************************************
 *
 * resume:
 * This function basically does just the opposite of what gotoexception does.
 * It loads each of the registers with what has been loaded into the regtbl[]
 * array and does an rte to load the PC and SR.
 * NOT WORKING YET!!!
 */
_resume:
    mov.l   p_regtbl,r0         /* Load R0 with regtbl[PC]. */
    add     #64,r0          
    mov.l   @r0,r0
    mov.l   p_regtbl,r1         /* Load R1 with regtbl[SP]. */
    mov.l   @(60,r1),r1 
    mov.l   r0,@r1              /* Place the regtbl[PC] value at the location */
                                /* pointed to be regtbl[SP]. */

    mov.l   p_regtbl,r0         /* Load R0 with regtbl[SR]. */
    add     #68,r0          
    mov.l   @r0,r0
    mov.l   r0,@(4,r1)          /* Place the regtbl[SR] value at the location */
                                /* pointed to be regtbl[SP] + 4. */

    mov.l   p_regtbl,r0         /* Load R0 with regtbl[PR]. */
    add     #72,r0              /* Restore PR */
    mov.l   @r0,r0
    lds     r0,pr

    /* At this point, the new stack is prepared for the rte.
     * Now just transfer all registers from regtbl[] to the actual registers...
     */

    mov.l   p_regtbl,r0         /* Load R0 with pointer regtbl[]. */
    mov.l   @(4,r0),r1          /* Restore R1 */
    mov.l   @(8,r0),r2          /* Restore R2 */
    mov.l   @(12,r0),r3         /* Restore R3 */
    mov.l   @(16,r0),r4         /* Restore R4 */
    mov.l   @(20,r0),r5         /* Restore R5 */
    mov.l   @(24,r0),r6         /* Restore R6 */
    mov.l   @(28,r0),r7         /* Restore R7 */
    mov.l   @(32,r0),r8         /* Restore R8 */
    mov.l   @(36,r0),r9         /* Restore R9 */
    mov.l   @(40,r0),r10        /* Restore R10 */
    mov.l   @(44,r0),r11        /* Restore R11 */
    mov.l   @(48,r0),r12        /* Restore R12 */
    mov.l   @(52,r0),r13        /* Restore R13 */
    mov.l   @(56,r0),r14        /* Restore R14 */
    mov.l   @(60,r0),r15        /* Restore R15 */
    mov.l   @r0,r0              /* Restore R0 */
    rte
    nop

    .align 2

p_regtbl:
    .long   _regtbl

p_exception:
    .long   _exception

p_exceptionCause:
    .long   _exceptionCause

p_MonStackEnd:
    .long   _MonStackEnd


/***************************************************************************
 *
 * Vector[4-255]:
 * At reset, the VBR points to address 0.  At this location there is a minimum
 * vector table containing the PC/SP for a manual and power-on reset.
 * The function vinit() (C code) re-establishes the VBR and loads one of these
 * exception handlers for each vector table entry.  They are all identical
 * except that after pushing R0 onto the stack, they load R0 with the 
 * vector number.
 */

    .globl _Vector4
_Vector4:
    mov.l   r0,@-r15        /* Push R0 onto the stack. */
    bra     gotoexception   /* Branch to the main exception handler with the */
    mov     #4,r0           /* delay slot loading R0 with the vector number. */

    .globl _Vector5
_Vector5:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #5,r0

    .globl _Vector6
_Vector6:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #6,r0

    .globl _Vector7
_Vector7:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #7,r0

    .globl _Vector8
_Vector8:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #8,r0

    .globl _Vector9
_Vector9:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #9,r0

    .globl _Vector10
_Vector10:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #10,r0

    .globl _Vector11
_Vector11:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #11,r0

    .globl _Vector12
_Vector12:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #12,r0

    .globl _Vector13
_Vector13:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #13,r0

    .globl _Vector14
_Vector14:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #14,r0

    .globl _Vector15
_Vector15:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #15,r0

    .globl _Vector16
_Vector16:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #16,r0

    .globl _Vector17
_Vector17:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #17,r0

    .globl _Vector18
_Vector18:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #18,r0

    .globl _Vector19
_Vector19:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #19,r0

    .globl _Vector20
_Vector20:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #20,r0

    .globl _Vector21
_Vector21:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #21,r0

    .globl _Vector22
_Vector22:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #22,r0

    .globl _Vector23
_Vector23:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #23,r0

    .globl _Vector24
_Vector24:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #24,r0

    .globl _Vector25
_Vector25:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #25,r0

    .globl _Vector26
_Vector26:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #26,r0

    .globl _Vector27
_Vector27:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #27,r0

    .globl _Vector28
_Vector28:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #28,r0

    .globl _Vector29
_Vector29:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #29,r0

    .globl _Vector30
_Vector30:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #30,r0

    .globl _Vector31
_Vector31:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #31,r0

    .globl _Vector32
_Vector32:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #32,r0

    .globl _Vector33
_Vector33:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #33,r0

    .globl _Vector34
_Vector34:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #34,r0

    .globl _Vector35
_Vector35:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #35,r0

    .globl _Vector36
_Vector36:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #36,r0

    .globl _Vector37
_Vector37:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #37,r0

    .globl _Vector38
_Vector38:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #38,r0

    .globl _Vector39
_Vector39:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #39,r0

    .globl _Vector40
_Vector40:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #40,r0

    .globl _Vector41
_Vector41:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #41,r0

    .globl _Vector42
_Vector42:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #42,r0

    .globl _Vector43
_Vector43:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #43,r0

    .globl _Vector44
_Vector44:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #44,r0

    .globl _Vector45
_Vector45:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #45,r0

    .globl _Vector46
_Vector46:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #46,r0

    .globl _Vector47
_Vector47:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #47,r0

    .globl _Vector48
_Vector48:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #48,r0

    .globl _Vector49
_Vector49:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #49,r0

    .globl _Vector50
_Vector50:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #50,r0

    .globl _Vector51
_Vector51:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #51,r0

    .globl _Vector52
_Vector52:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #52,r0

    .globl _Vector53
_Vector53:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #53,r0

    .globl _Vector54
_Vector54:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #54,r0

    .globl _Vector55
_Vector55:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #55,r0

    .globl _Vector56
_Vector56:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #56,r0

    .globl _Vector57
_Vector57:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #57,r0

    .globl _Vector58
_Vector58:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #58,r0

    .globl _Vector59
_Vector59:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #59,r0

    .globl _Vector60
_Vector60:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #60,r0

    .globl _Vector61
_Vector61:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #61,r0

    .globl _Vector62
_Vector62:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #62,r0

    .globl _Vector63
_Vector63:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #63,r0

    .globl _Vector64
_Vector64:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #64,r0

    .globl _Vector65
_Vector65:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #65,r0

    .globl _Vector66
_Vector66:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #66,r0

    .globl _Vector67
_Vector67:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #67,r0

    .globl _Vector68
_Vector68:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #68,r0

    .globl _Vector69
_Vector69:
    mov.l   r0,@-r15
    bra     gotoexception
    mov     #69,r0

    .globl _Vector70