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path: root/src/cpu/amd/car/clear_1m_ram.c
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/* by yhlu 6.2005 */
/* be warned, this file will be used core 0/node 0 only */
static inline __attribute__((always_inline)) void clear_1m_ram(void)
{
        __asm__ volatile (

        /* disable cache */
        "movl    %%cr0, %%eax\n\t"
        "orl    $(0x1<<30),%%eax\n\t"
        "movl    %%eax, %%cr0\n\t"

        /* enable caching for first 1M using variable mtrr */
        "movl    $0x200, %%ecx\n\t"
        "xorl    %%edx, %%edx\n\t"
	"movl     $(0 | 1), %%eax\n\t"
//	"movl     $(0 | MTRR_TYPE_WRCOMB), %%eax\n\t"
        "wrmsr\n\t"

        "movl    $0x201, %%ecx\n\t"
        "movl    $0x0000000f, %%edx\n\t" 
#if CONFIG_USE_INIT
	"movl  %%esi, %%eax\n\t"
#else
	"movl    $((~(( 0 + (CONFIG_LB_MEM_TOPK<<10) ) -1)) | 0x800), %%eax\n\t"
#endif
        "wrmsr\n\t"

        /* clear the first 1M */
#if CONFIG_USE_INIT
	"movl    %%edi, %%ecx\n\t"
#else
	"movl    $((CONFIG_LB_MEM_TOPK<<10)>>2), %%ecx\n\t"	
#endif
        "xorl %%edi, %%edi\n\t"
        "cld\n\t"
        "xorl    %%eax, %%eax\n\t"
        "rep     stosl\n\t"

        /* disable cache */
        "movl   %%cr0, %%eax\n\t"
        "orl    $(0x1<<30),%%eax\n\t"
        "movl    %%eax, %%cr0\n\t"

        /* enable caching for first 1M using variable mtrr */
        "movl    $0x200, %%ecx\n\t"
        "xorl    %%edx, %%edx\n\t"
	"movl     $(0 | 6), %%eax\n\t"
//	"movl     $(0 | MTRR_TYPE_WRBACK), %%eax\n\t"
        "wrmsr\n\t"

        "movl    $0x201, %%ecx\n\t"
        "movl    $0x0000000f, %%edx\n\t" 
#if CONFIG_USE_INIT
	"movl	 %%esi, %%eax\n\t"
#else
	"movl    $((~(( 0 + (CONFIG_LB_MEM_TOPK<<10) ) -1)) | 0x800), %%eax\n\t"
#endif
        "wrmsr\n\t"

        /* enable cache */
        "movl    %%cr0, %%eax\n\t"
        "andl    $0x9fffffff,%%eax\n\t"
        "movl    %%eax, %%cr0\n\t"
	"invd\n\t"
	:
	:
#if CONFIG_USE_INIT
	"S"((~(( 0 + (CONFIG_LB_MEM_TOPK<<10) ) -1)) | 0x800), "D" ((CONFIG_LB_MEM_TOPK<<10)>>2)
#endif
        );
}