FW: why MTD model ?

FW: why MTD model ?

[Stephan Linke]

Hi!

> 
> Can somehow we treat(emulate) memory device as a block
> device and treat memory device like a hard disk ?
>

Maybe I didn't got the point. But if you like to use some (maybe 
battery backuped) memory with a filesystem on it you could setup 
your MTD device just like this:
>>>>

static void* memremap;                                            
              
static struct mtd_info *myrammtd;                                 
              

__u8 my_ram_read8(struct map_info *map, unsigned long ofs)
{
    return *(__u8 *)(memremap  + ofs);
}
...

struct map_info my_ram_map = {
    name: "MY bbram    ",
    size: RAM_WINDOW_SIZE,
    buswidth: 4,
    read8: my_ram_read8,
    read16: my_ram_read16,
    read32: my_ram_read32,
    copy_from: my_ram_copy_from,
    write8: my_ram_write8,
    write16: my_ram_write16,
    write32: my_ram_write32,
    copy_to: my_ram_copy_to
};


...
        myrammtd = do_map_probe("map_ram", &my_ram_map);          
            
        if (myrammtd) {
            memremap = ioremap (RAM_WINDOW_ADDR, RAM_WINDOW_SIZE);
            add_mtd_device (myrammtd);
        } else {
            printk ("mtd/my.o: error installing bbdram device!\n");
        }
        return 0;
...

<<<<
(If someone thinks that this is the wrong way, feel free to send 
comments.) :o)



Stephan Linke
>