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#define RSDP_BASE_1  0xE0000
#define RSDP_END_1   0xFFFFF
#define BIOS_EBDA_PA 0x40E

#define RSDP_SIG "RSD PTR "
#define RSDT_SIG "RSDT"
#define XSDT_SIG "XSDT"
#define APIC_SIG "APIC"


static PRSDP_DESC scan_for_rsdp (char* start, UINT32 length)
{
    char* end = start + length;

    for (; start < end; start += 16)
    {
        if (!TPmemcmp(start, RSDP_SIG, sizeof(RSDP_SIG) -1))
            return (PRSDP_DESC)start;
    }
    return NULL;
}

void* map_physical_region_cached(UINT64 base, size_t size)
{
    return ioremap_cache(base, size);
}

BOOLEAN get_acpi_table(const char* sig, PACPI_TBL* out_tbl, UINT32* out_tbl_size)
{
   PRSDP_DESC p;
   char *rsdp = NULL;

   rsdp = (char*)map_physical_region_cached(RSDP_BASE_1, RSDP_END_1 - RSDP_BASE_1);
   if (!rsdp)
       goto ebda;

   if ((p = scan_for_rsdp(rsdp, RSDP_END_1 - RSDP_BASE_1)) == NULL)
        goto ebda;

   goto found;
ebda:
   {
      UINT16 ebda_rm_segment = *(u16*)map_physical_region_cached(0x40E,2);
      rsdp = (char*)map_physical_region(((UINT32)ebda_rm_segment)*16,1024);

      if (!rsdp)
        return FALSE;

       if ((p = scan_for_rsdp(rsdp, 1024)) == NULL)
         return FALSE;    
   }
found:
   //rest of the code
}

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