Ralf,
It worked fine with small changes!! Comment and Criticism are welcome.
>Other than that you can also just setup your system >as 0x0 - 0x10000000 being RAM, 0x10000000 - 0x20000000 being reserved >memory and 0x20000000 - 0x30000000 being highmem. Which works but is a >bit wasteful.
I have set up my system as following :
- 0x00000000 - 0x10000000 RAM
- 0x10000000 - 0x40000000 RESERVED
- 0x40000000 - 0x50000000 RAM
So that the gap in physical address space and one in virtual address space becomes equal.
It is 0x40000000 in this case (0x10000000 - 0x40000000 vs 0x90000000 - 0xc0000000).
That means no physical <-> virtual macro change are needed. hehe...
And the MMU mapping to the upper 256MB is fixed with the CP0 wired register.
Changes are pretty small as follows : --- tlb-r4k.c --- 381c381 < write_32bit_cp0_register(CP0_WIRED, 0); ---
write_32bit_cp0_register(CP0_WIRED, 8 /* XXX 0 */);
--- pgtable.h --- 123c123 < #define VMALLOC_START KSEG2 ---
#define VMALLOC_START KSEG3 /* XXX KSEG2 */
--- page.h --- 148c148 < #define HIGHMEM_START 0x20000000UL ---
#define HIGHMEM_START 0x50000000UL /* XXX 0x20000000UL */
--- prom.c ---
add_memory_region(0, (256*1024*1024), BOOT_MEM_RAM); add_memory_region(0x10000000, (256*1024*1024), BOOT_MEM_RESERVED); add_memory_region(0x20000000, (512*1024*1024), BOOT_MEM_RESERVED); add_memory_region(0x40000000, (256*1024*1024), BOOT_MEM_RAM);
{ TLB_TBL32 tlb; unsigned int nTlb = 48; /* max TLB entry */ unsigned int size = 0x02000000; /* 32MB boundary */ unsigned int vadr = 0xc0000000; /* virtual address */ unsigned int padr = 0x40000000; /* physical address */
printk ("memory map started.\n");
for (i=0; i<8; i++)
{
tlb.mask = 0x01ffe000; /* 16M bit[24-13] */
tlb.hi = vadr + (i*size);
tlb.lo1 = (padr >> 6) | ((i*size + (size/2)) >> 6) | 0x1f;
tlb.lo0 = (padr >> 6) | ((i*size) >> 6) | 0x1f;
setTLB32 (i, &tlb);
}
for (i=8; i<nTlb; i++)
{
tlb.mask = 0x0;
tlb.hi = 0x80000000;
tlb.lo1 = 0;
tlb.lo0 = 0;
setTLB32 (i, &tlb);
}
for (i=0; i<nTlb; i++)
{
getTLB32 (i, &tlb);
printk ("get: mask=0x%08x hi=0x%08x lo0=0x%08x lo1=0x%08x.\n",
tlb.mask, tlb.hi, tlb.lo0, tlb.lo1);
}
}
Cheers, -hdei
