Question about Data Cache and the compiler

Hi Bernd,

First, do what Danny suggests: read the manual.

Then review: http://forum.niosforum.com/forum/index.php?showtopic=3190 (http://forum.niosforum.com/forum/index.php?showtopic=3190)

Then the following will be more useful:

> I tried to use initd instruction after storing the registers onto the stack and

> before resetting the Nios

Use flushd to flush the entire data cache. Look at alt_dcache_flush_all() ... but do

pay attention to the bug fix by James in the topic above.

Or from u-boot:

    /* flush_dcache (unsigned char *p, int len)
     *
     * To flush entire cache:
     *        flush_dcache ((unsigned char *)0L, DCACHE_SIZE)
     */
    .text
    .global flush_dcache
flush_dcache:
    add    r5, r5, r4
    movhi    r8, %hi(CFG_DCACHELINE_SIZE)
    ori    r8, r8, %lo(CFG_DCACHELINE_SIZE)
0:    flushd    0(r4)
    add    r4, r4, r8
    bltu    r4, r5, 0b
    ret

Regards,

--Scott