flashpic.c

完整的Bell实验室的嵌入式文件系统TFS

/* flashpic.c:
   This file contains the flash-support code that is relocated to
   RAM prior to execution.  This file currently only supports the
   device when configured in 16-bit mode.
*/
#include "config.h"
#if INCLUDE_FLASH
typedef unsigned char uchar;
typedef unsigned short ushort;
typedef unsigned long ulong;
typedef volatile unsigned char vuchar;
typedef volatile unsigned short vushort;
typedef volatile unsigned long vulong;
typedef volatile unsigned int vuint;
typedef volatile int vint;

#include "cpu.h"
#include "flashdev.h"
#include "flash.h"

#define WSMS    0x0080
#define ESS     0x0040
#define ES      0x0020
#define PSS     0x0004
#define PS      0x0010

extern struct flashinfo Fdev;
extern int FlashProtectWindow;

int
Flashlock16(struct flashinfo *fdev,int snum,int operation)
{
    ulong   add;
    int sector;

    add = (ulong)(fdev->base);

    /* Lock the requested sector(s): */
    for (sector=0;sector<fdev->sectorcnt;sector++) {
        if ((snum == ALL_SECTORS) || (snum == sector)) {
            /* Issue the appropriate command sequence: */
            Write_60_to_base(); 
            switch(operation) {
            case FLASH_UNLOCK:
                Write_d0_to_(add);
                break;
            case FLASH_LOCK:
                Write_01_to_(add);
                break;
            case FLASH_LOCKDWN:
                Write_2f_to_(add);
                break;
            }
        }
        add += fdev->sectors[sector].size;
    }
    Write_FF_to_base();     /* Go to read-array mode */
    return(0);
}

void
EndFlashlock16()
{}

/* Flasherase():
   Based on the 'snum' value, erase the appropriate sector(s).
   Write the "Erase Setup" and "Erase Confirm" commands...
   Return 0 if success, else -1.
*/
int
Flasherase16(struct flashinfo *fdev,int snum)
{
    ulong   add;
    int ret, sector;

    ret = 0;
    add = (ulong)(fdev->base);

    /* Erase the request sector(s): */
    for (sector=0;sector<fdev->sectorcnt;sector++) {
        if ((!FlashProtectWindow) &&
            (fdev->sectors[sector].protected)) {
            add += fdev->sectors[sector].size;
            continue;
        }
        if ((snum == ALL_SECTORS) || (snum == sector)) {
            register ulong *lp, *lp1;
            int noterased;

            /* See if the sector is already erased: */
            noterased = 0;
            lp = (ulong *)fdev->sectors[sector].begin; 
            lp1 = (ulong *)((char *)lp + fdev->sectors[sector].size); 
            while(lp < lp1) {
                if (*lp++ != 0xffffffff) {
                    noterased = 1;
                    break;
                }
            }
            if (noterased) {
                /* Issue the setup/confirm sequence: */
                Write_20_to_base();     /* setup */
                Write_d0_to_(add);      /* confirm */

                /* Wait for sector erase to complete by polling RSR... */
                Write_70_to_base();
                while(1) {
                    ushort rsr;

                    rsr = Read_0000();
                    if (!(rsr & WSMS))  /* Wait till ready */
                        continue;
                    if (rsr & ESS)      /* Should not be suspended */
                        ret = -1;
                    if (rsr & ES)       /* Should not have error */
                        ret = -1;
                    break;
                }
                Write_50_to_base();     /* Clear status register */
                Write_FF_to_base();     /* Go to read-array mode */
            }
            if (ret == -1)
                break;
        }
        add += fdev->sectors[sector].size;
    }
    return(ret);
}

/* EndFlasherase():
   Function place holder to determine the "end" of the
   sectorerase() function.
*/
void
EndFlasherase16()
{
}


/* Flashwrite():
   Return 0 if successful, else -1.
*/
int
Flashwrite16(struct flashinfo *fdev,uchar *dest,uchar *src,long bytecnt)
{
    int     i, ret;
    long    cnt;
    uchar   *src1;
    ftype   val;

    /* If destination address is not properly aligned, then build a fake   */
    /* source buffer based on the current value in dest[-1] and src[0].    */
    /* Then call this function to do that 2-byte operation.  Once that     */
    /* completes, simply increment dest and src by 1 and continue in this  */
    /* context. */
    if (NotAligned(dest)) {
        uchar buf[2];
        buf[0] = *(dest-1);
        buf[1] = *src;
        Flashwrite16(fdev,dest-1,buf,2);
        dest++; src++; bytecnt--;
    }

    /* Each pass through this loop writes 'fdev->width' bytes... */
    ret = 0;
    cnt = bytecnt & ~1;
    src1 = (uchar *)&val;

onemore:
    for (i=0;i<cnt;i+=fdev->width) {

       /* Just in case src is not aligned... */
        src1[0] = src[0];
        src1[1] = src[1];

        /* Flash program setup command */
        Write_40_to_base();
          
        /* Write the value */
        Fwrite(dest,src1);

        /* Wait for write to complete or timeout. */
        Write_70_to_base();
        while(1) {
            ushort rsr;

            rsr = Read_0000();
            if (!(rsr & WSMS))  /* Wait till ready */
                continue;
            if (rsr & PSS)      /* Should not be suspended */
                ret = -1;
            if (rsr & PS)       /* Should not have error */
                ret = -1;
            break;
        }
        Write_50_to_base();     /* Clear status register */
        Write_FF_to_base();     /* Go to read-array mode */
        dest += fdev->width; 
        src += fdev->width;
    }

    /* If bytecount was odd... */
    /* If cnt != bytecnt then bytecnt is odd, so one more byte must be */
    /* written to flash.  To do this, the one byte must be combined with */
    /* the next byte that is already stored in flash; then re-written... */
    if (cnt != bytecnt) {
        val = (ftype)*dest | ((ftype)(*src) << 8);
        src = (uchar *)&val;
        bytecnt = cnt = 1;
        goto onemore;
    }

    return(ret);
}

/* EndFlashwrite():
    Function place holder to determine the "end" of the
    Flashwrite() function.
*/
void
EndFlashwrite16()
{
}

/* Ewrite():
   Erase all sectors that are part of the address space to be written,
   then write the data to that address space.  This is basically a
   concatenation of flasherase and flashwrite done in one step.  This is
   necessary primarily for re-writing the bootcode; because after the boot
   code is erased, there is nowhere to return so the re-write must be done
   while executing out of ram also.
*/

int
Flashewrite16(struct flashinfo *fdev,ftype *dest,ftype *src,int bytecnt)
{
    int i, err;
    ulong   add;
    void    (*reset)();
    ftype   *src1;

    err = 0;
    add = (ulong)(fdev->base);
    src1 = src;

    /* For each sector, if it overlaps any of the destination space */
    /* then erase that sector. */
    for (i=0;i<fdev->sectorcnt;i++) {
        if ((((uchar *)dest) > (fdev->sectors[i].end)) ||
            (((uchar *)dest+bytecnt) < (fdev->sectors[i].begin))) {
            add += fdev->sectors[i].size;
            continue;
        }

        /* Issue the ERASE setup/confirm sequence: */
        Write_20_to_base();     /* setup */
        Write_d0_to_(add);      /* confirm */

        /* Wait for sector erase to complete by polling RSR... */
        Write_70_to_base();
        while(1) {
            ushort rsr;

            rsr = Read_0000();
            if (!(rsr & WSMS))  /* Wait till ready */
                continue;
            if (rsr & ESS)      /* Should not be suspended */
                err = 1;
            if (rsr & ES)       /* Should not have error */
                err = 1;
            break;
        }
        Write_50_to_base();     /* Clear status register */
        Write_FF_to_base();     /* Go to read-array mode */
        if (err)
            return(-1);
        add += fdev->sectors[i].size;
    }

    for(i=0;i<bytecnt;i+=fdev->width) {
        /* Flash program setup command */
        Write_40_to_base();
        
        /* Just in case src is not aligned... */
        src1[0] = src[0];
        src1[1] = src[1];

        /* Write the value */
        Fwrite(dest,src1);

        /* Wait for write to complete by polling RSR... */
        Write_70_to_base();
        while(1) {
            ushort rsr;

            rsr = Read_0000();
            if (!(rsr & WSMS))  /* Wait till ready */
                continue;
            if (rsr & PSS)      /* Should not be suspended */
                err = 1;
            if (rsr & PS)       /* Should not have error */
                err = 1;
            break;
        }
        Write_50_to_base();     /* Clear status register */
        Write_FF_to_base();     /* Go to read-array mode */
        if (err)
            return(-1);
        dest++; 
        src++;
    }
    
    /* Wait till flash is readable, then reset: */
    while(1) {
        if (Is_Equal((dest-1),src1))
            break;
    }

    /* Now that the re-programming of flash is complete, reset: */
    reset = RESETFUNC();
    reset();

    return(0);  /* won't get here */
}

/* EndFlashewrite():
    Function place holder to determine the "end" of the
    FlashEraseAndWrite() function.
*/
void
EndFlashewrite16()
{
}

/* Flashtype():
   Use the ReadCOnfiguration command (90H) to read manufacturer code (0000)
   and device id code (0001).
*/

int
Flashtype16(struct flashinfo *fdev)
{
    ftype   val;
    ushort  man, dev;
    ulong   id;

    val = Read_0000();

    /* Issue the read configuration command: */
    Write_90_to_base();

    man = (ushort)Read_0000();  /* manufacturer ID */
    dev = (ushort)Read_0001();  /* device ID */
    id = man;
    id <<= 16;
    id |= dev;

    fdev->id = id;

    /* Issue the read array command: */
    Write_FF_to_base();
    return((int)(fdev->id));
}

/* EndFlashtype():
    Function place holder to determine the "end" of the
    Flashtype() function.
*/
void
EndFlashtype16()
{
}
#endif