[LinuxBIOS] EPIA-M + EPIA-SP V2 cache init

[Dave Ashley]

I've had success in V2 for EPIA-SP by pulling ASM code from V1 and
replacing the whole early_mtrr_init() call from V2, with this, placed
right at the start of auto.c (see below). The romcc generated code works
fast enough, but it really makes a difference when the linux kernel is
uncompressed later. I don't really know what is happening though, I'm not
an expert on the low level cache setup. There is difference between
the V2 early_mtrr_init functionality and what was in V1.

__asm__ volatile (
"\n"
"        invd\n"
"earlymtrr_start:\n"
"        xorl %%eax, %%eax\n"
"        xorl %%edx, %%edx\n"
"        movl $fixed_mtrr_msr, %%esi\n"
"clear_fixed_var_mtrr:\n"
"        lodsl (%%esi), %%eax\n"
"        testl %%eax, %%eax\n"
"        jz clear_fixed_var_mtrr_out\n"
"        movl %%eax, %%ecx\n"
"        xorl %%eax, %%eax\n"
"        wrmsr\n"
"        jmp clear_fixed_var_mtrr\n"
"clear_fixed_var_mtrr_out:\n"
"set_fixed_mtrr:\n"
"        movl $0x250, %%ecx\n"
"        rdmsr\n"
"        movl $0x06060606, %%edx\n"
"        movl $0x06060606, %%eax\n"
"        wrmsr\n"
"        movl $0x258, %%ecx\n"
"        rdmsr\n"
"        movl $0x06060606, %%edx\n"
"        movl $0x06060606, %%eax\n"
"        wrmsr\n"
"set_var_mtrr:\n"
"        movl $0x200, %%ecx\n"
"        rdmsr\n"
"        andl $0xfffffff0, %%edx\n"
"        orl $0x00000000, %%edx\n"
"        andl $0x00000f00, %%eax\n"
"        orl $0x00000006, %%eax\n"
"        wrmsr\n"
"        movl $0x201, %%ecx\n"
"        rdmsr\n"
"        andl $0xfffffff0, %%edx\n"
"        orl $0x0000000f, %%edx\n"
"        andl $0x000007ff, %%eax\n"
"        orl $0xf0000800, %%eax\n"
"        wrmsr\n"
"enable_mtrr:\n"
"        movl $0x2ff, %%ecx\n"
"        xorl %%edx, %%edx\n"
"        movl $0x00000c00, %%eax\n"
"        wrmsr\n"
"        movl %%cr0, %%eax\n"
"        andl $0x9fffffff,%%eax\n"
"        movl %%eax, %%cr0\n"
"        jmp earlymtrr_end\n"
"fixed_mtrr_msr:\n"
"        .long 0x250, 0x258, 0x259\n"
"        .long 0x268, 0x269, 0x26A\n"
"        .long 0x26B, 0x26C, 0x26D\n"
"        .long 0x26E, 0x26F\n"
"var_mtrr_msr:\n"
"        .long 0x200, 0x201, 0x202, 0x203\n"
"        .long 0x204, 0x205, 0x206, 0x207\n"
"        .long 0x208, 0x209, 0x20A, 0x20B\n"
"        .long 0x20C, 0x20D, 0x20E, 0x20F\n"
"        .long 0x000\n"
"earlymtrr_end:\n");