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#include <cpu/k8/mtrr.h>
/* the fixed and variable MTTRs are power-up with random values,
* clear them to MTRR_TYPE_UNCACHEABLE for safty.
*/
static void early_mtrr_init(void)
{
static unsigned long mtrr_msrs[] = {
/* fixed mtrr */
0x250, 0x258, 0x259,
0x268, 0x269, 0x26A
0x26B, 0x26C, 0x26D
0x26E, 0x26F,
/* var mtrr */
0x200, 0x201, 0x202, 0x203,
0x204, 0x205, 0x206, 0x207,
0x208, 0x209, 0x20A, 0x20B,
0x20C, 0x20D, 0x20E, 0x20F,
/* var iorr msr */
0xC0010016, 0xC0010017, 0xC0010018, 0xC0010019,
/* mem top */
0xC001001A, 0xC001001D,
/* NULL end of table */
0
};
msr_t msr;
unsigned long *msr_addr;
/* Inialize all of the relevant msrs to 0 */
msr.lo = 0;
msr.hi = 0;
for(msr_addr = &mtrr_msrs; *msr_addr; msr_addr++) {
wrmsr(*msr_addr, msr);
}
/* Enable memory access for 0 - 8MB using top_mem */
msr.hi = 0;
msr.lo = 0x08000000;
wrmsr(TOP_MEM, msr);
/* Enable caching for 0 - 128MB using variable mtrr */
msr = rdmsr(0x200);
msr.hi &= 0xfffffff0;
msr.hi |= 0x00000000;
msr.lo &= 0x00000f00;
msr.lo |= 0x00000006;
wrmsr(0x200, msr);
msr = rdmsr(0x201);
msr.hi &= 0xfffffff0;
msr.hi |= 0x0000000f;
msr.lo &= 0x000007ff;
msr.lo |= 0xf0000800;
wrmsr(0x201, msr);
#if defined(XIP_ROM_SIZE) && defined(XIP_ROM_BASE)
/* enable write back caching so we can do execute in place
* on the flash rom.
*/
msr.hi = 0x00000000;
msr.lo = XIP_ROM_BASE | 0x005;
wrmsr(0x202);
#error "FIXME verify the type of MTRR I have setup"
msr.hi = 0x0000000f;
msr.lo = ~(XIP_ROM_SIZE - 1) | 0x800;
wrmsr(0x203);
#endif
/* Set the default memory type and enable fixed and variable MTRRs
*/
/* Enable Variable MTRRs */
msr.hi = 0x00000000;
msr.lo = 0x00000800;
wrmsr(0x2ff, msr);
/* Enale the MTRRs in SYSCFG */
msr = rdmsr(SYSCFG_MSR);
msr.lo |= SYSCFG_MSR_MtrrrVarDramEn;
wrmsr(SYSCFG_MSR, msr);
/* Enable the cache */
unsigned long cr0;
cr0 = read_cr0();
cr0 &= 0x9fffffff;
write_cr0(cr0);
}
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