diff options
Diffstat (limited to 'src/northbridge/intel/i945/ram_calc.c')
-rw-r--r-- | src/northbridge/intel/i945/ram_calc.c | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/src/northbridge/intel/i945/ram_calc.c b/src/northbridge/intel/i945/ram_calc.c new file mode 100644 index 0000000000..4ece5402fb --- /dev/null +++ b/src/northbridge/intel/i945/ram_calc.c @@ -0,0 +1,57 @@ +/* + * This file is part of the coreboot project. + * + * Copyright (C) 2007-2009 coresystems GmbH + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; version 2 of the License. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + */ + +// Use simple device model for this file even in ramstage +#define __SIMPLE_DEVICE__ + +#include <arch/io.h> +#include <cbmem.h> +#include "i945.h" + +unsigned long get_top_of_ram(void) +{ + u32 tom; + + if (pci_read_config8(PCI_DEV(0, 0x0, 0), DEVEN) & ((1 << 4) | (1 << 3))) { + /* IGD enabled, get top of Memory from BSM register */ + tom = pci_read_config32(PCI_DEV(0,2,0), 0x5c); + } else { + tom = (pci_read_config8(PCI_DEV(0,0,0), TOLUD) & 0xf7) << 24; + } + + /* if TSEG enabled subtract size */ + switch(pci_read_config8(PCI_DEV(0, 0, 0), ESMRAM)) { + case 0x01: + /* 1MB TSEG */ + tom -= 0x10000; + break; + case 0x03: + /* 2MB TSEG */ + tom -= 0x20000; + break; + case 0x05: + /* 8MB TSEG */ + tom -= 0x80000; + break; + default: + /* TSEG either disabled or invalid */ + break; + } + return (unsigned long) tom; +} |