jffs2+mtd+big endian problem

[Li Yang]

On Mon, 2004-01-19 at 19:04, David Woodhouse wrote:
> On Mon, 2004-01-19 at 18:58 +0800, Li Yang wrote:
> > I have some problem accessing CVS from the damned corporate network. 
> 
> How strange. I can make the machine available for dialin if you want --
> it's funny how a few international phone calls make managers suddenly
> want to lean on incompetent IS staff to fix broken firewalls :)

Well, I hope i can do so.  But I have to get a modem first.  =)

> 
> If you really can't even use CONNECT through an HTTP proxy, there are
> nightly snapshots at ftp://ftp.uk.linux.org/pub/people/dwmw2/mtd/cvs/

No, I can't use CONNECT through an HTTP proxy.  I think they intend to
do so due to some *security* reason, anyway, the network is absolutely
not secure in my opinion.  It's so kind of you to provide the snapshot.

> 
> > The image generated by mkfs.jffs2 with -b seems ok, but it's not all
> > right after I done some operations on the target.  In the bottom is the
> > log of these operations.
> > 
> > Yes, I have examined a section which is formatted by the target board. 
> > The first several bytes of the section are:  
> > 
> > fe3c0000: 03208519 0c000000 98dc60f0 ffffffff    . ........`.....
> > fe3c0010: ffffffff ffffffff ffffffff ffffffff    ................
> > 
> > They are all 32-bit swapped.  I traced into the JFFS2 code, and know it
> > use mtd->write to write data into flash.  Which function is it turned
> > out to be finally?  Is it the write defined in the drivers/mtd/maps/
> > files?  I used __raw_write*() at the very beginning, it shouldn't be
> > like this.
> 
> This sounds like you're using byte-swapping operations in your map
> driver. You should be using __raw_write*() not write*(). You said you
> were 'at the very beginning'... are you still doing that now?

I have verified my maps/ file.  I'm using __raw_write*() now.  Here is
part of my maps file, I don't know if the memcpy_toio() matters.

#define WINDOW_ADDR 0xfe000000
#define WINDOW_SIZE 0x800000
                                                                                                       
static struct mtd_partition physmap_partitions[] = {
/* Put your own partition definitions here */
        {
                name:           "JFFS2",
                size:           0x600000,
                offset:         0,
        }, {
                name:           "uImage",
                size:           0x100000,
                offset:         0x600000,
                mask_flags:     MTD_WRITEABLE,  /* force read-only */
        }, {
                name:           "u-boot",
                size:           0x40000,
                offset:         0x700000,
                mask_flags:     MTD_WRITEABLE,  /* force read-only */
        }, {
                name:           "u-boot env",
                size:           0x40000,
                offset:         0x740000,
                mask_flags:     MTD_WRITEABLE,  /* force read-only */
        }
};
                                                                                                       
#define NUM_PARTITIONS  (sizeof(physmap_partitions)/sizeof(struct
mtd_partition))
                                                                                                       
static struct mtd_info *mymtd;
                                                                                                       
__u8 ads_read8(struct map_info *map, unsigned long ofs)
{
        return __raw_readb(map->map_priv_1 + ofs);
}
                                                                                                       
__u16 ads_read16(struct map_info *map, unsigned long ofs)
{
        return __raw_readw(map->map_priv_1 + ofs);
}
                                                                                                       
__u32 ads_read32(struct map_info *map, unsigned long ofs)
{
        return __raw_readl(map->map_priv_1 + ofs);
}
                                                                                                       
void ads_copy_from(struct map_info *map, void *to, unsigned long from,
ssize_t len)
{
        memcpy_fromio(to, (void *)(map->map_priv_1 + from), len);
}
                                                                                                       
void ads_write8(struct map_info *map, __u8 d, unsigned long adr)
{
        __raw_writeb(d, map->map_priv_1 + adr);
        mb();
}
                                                                                                       
void ads_write16(struct map_info *map, __u16 d, unsigned long adr)
{
        __raw_writew(d, map->map_priv_1 + adr);
        mb();
}
                                                                                                       
void ads_write32(struct map_info *map, __u32 d, unsigned long adr)
{
        __raw_writel(d, map->map_priv_1 + adr);
        mb();
}
                                                                                                       
void ads_copy_to(struct map_info *map, unsigned long to, const void
*from, ssize_t len)
{
        memcpy_toio((void *)(map->map_priv_1 + to), from, len);
}

struct map_info ads_map = {
        name: "Flash SIMM",
        size: WINDOW_SIZE,
        buswidth: 4,
        read8: ads_read8,
        read16: ads_read16,
        read32: ads_read32,
        copy_from: ads_copy_from,
        write8: ads_write8,
        write16: ads_write16,
        write32: ads_write32,
        copy_to: ads_copy_to
};


--
Thank you 
Leo