problems with MPC850 cache

Sergey Ablalimov sa at design.morion.ru
Wed Sep 1 08:27:30 UTC 2004


Hi,
I try enable I- and D-cache on our MPC850 board. My BSP based on mbx8xx. When
I/D-cache disabled - all work.
I presume that it is mmu initialization problem, but can't find it.
Can anybody help me?

MMU_TLB_table_t MMU_TLB_table[] = {
   /*
         * SDRAM: Start address 0x00000000, 16M,
         *      ASID=0x0, APG=0x0, not guarded memory,
         *      R/W,X for all, no ASID comparison, not cache-inhibited.
         * EPN          TWC     RPN
         */
   { 0x00000200, 0x0D, 0x000009FD },    /* DRAM - PS=8M */
   { 0x00800200, 0x0D, 0x008009FD },    /* DRAM - PS=8M */

        /*
         *
         * boot_flash: Start address 0xfff00000, 512K,
         *      ASID=0x0, APG=0x0, not guarded memory,
         *      R/W,X for all, no ASID comparison, cache-inhibited.
         *
         * EPN          TWC     RPN
         */
        { 0xFFF00200,   0x05,   0xFFF009FF },   /* boot_flash - PS=512K */

        /*
         *
         * flash_disk: Start address 0x01200000 4x2Kb
         *      ASID=0x0, APG=0x0, not guarded memory,
         *      R/W,X for all, no ASID comparison, cache-inhibited.
         * EPN          TWC     RPN
         */
        { 0x01200200,   0x01,   0x012009F7 },   /* flash_disk - PS=4K */
        { 0x01201200,   0x01,   0x012019F7 },   /* flash_disk - PS=4K */
        /*
         *
         * pld: Start address 0x02000000, 256K,
         *      ASID=0x0, APG=0x0, not guarded memory,
         *      R/W,X for all, no ASID comparison, cache-inhibited.
         * EPN          TWC     RPN
         */
        { 0x02000200,   0x05,   0x020009FF },   /* pld - PS=512K */

        /*
         *
         * (IMMR-SPRs) Dual Port RAM: Start address 0xFA200000, 16K,
         *      ASID=0x0, APG=0x0, guarded memory, write-through data cache policy,
         *      R/W,X for all, no ASID comparison, cache-inhibited.
         * EPN          TWC     RPN
         */
        { 0xFA200200,   0x13,   0xFA2009FF }    /* IMMR - PS=16K */

};
In ...\cpukit\score\cpu\powerpc\rtems\score\ppc.h for mpc850 I add:

#define PPC_ALIGNMENT         4
#define PPC_I_CACHE           2048
#define PPC_D_CACHE           1024
#define PPC_CACHE_ALIGNMENT     16
#define PPC_HAS_FPU              0
#define PPC_HAS_DOUBLE           0
#define PPC_USE_MULTIPLE         1


-- 
 Sergey


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