Init for the Intel 82371EB southbridge: make all ROM/BIOS regions

accessible (but not writable), so that reading/loading a payload
from that area can work (for instance).

Signed-off-by: Uwe Hermann <uwe@hermann-uwe.de>
Acked-by: Stefan Reinauer <stepan@coresystems.de>



git-svn-id: svn://svn.coreboot.org/coreboot/trunk@2700 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1
This commit is contained in:
Uwe Hermann 2007-05-27 21:43:58 +00:00
parent 4834a4f206
commit 4cb85533dd
2 changed files with 33 additions and 1 deletions

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@ -18,12 +18,42 @@
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
/* Datasheet:
* - Name: 82371AB PCI-TO-ISA / IDE XCELERATOR (PIIX4)
* - URL: http://www.intel.com/design/intarch/datashts/290562.htm
* - PDF: http://www.intel.com/design/intarch/datashts/29056201.pdf
* - Order Number: 290562-001
*/
#include <console/console.h>
#include <device/device.h>
#include <device/pci.h>
#include "i82371eb.h"
/**
* Enable access to all BIOS regions. Do not enable write access to the ROM.
*
* @param dev TODO
*/
void i82371eb_enable(device_t dev)
{
/* TODO. */
uint16_t reg;
/* Set bit 9: 1-Meg Extended BIOS Enable (PCI master accesses to
* FFF00000-FFF7FFFF are forwarded to ISA).
* Set bit 7: Extended BIOS Enable (PCI master accesses to
* FFF80000-FFFDFFFF are forwarded to ISA).
* Set bit 6: Lower BIOS Enable (PCI master, or ISA master accesses to
* the lower 64-Kbyte BIOS block (E0000-EFFFF) at the top
* of 1 Mbyte, or the aliases at the top of 4 Gbyte
* (FFFE0000-FFFEFFFF) result in the generation of BIOSCS#.
* Note: Accesses to FFFF0000-FFFFFFFF are always forwarded to ISA.
* Set bit 2: BIOSCS# Write Enable (1=enable, 0=disable).
*/
reg = pci_read_config16(dev, XBCS);
reg |= 0x2c0;
pci_write_config16(dev, XBCS, reg);
}
struct chip_operations southbridge_intel_i82371eb_ops = {

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@ -25,6 +25,8 @@
#include "chip.h"
#define XBCS 0x4e /* X-Bus Chip Select register */
void i82371eb_enable(device_t dev);
#endif