| /* SPDX-License-Identifier: GPL-2.0-only */ |
| /* This file is part of the coreboot project. */ |
| |
| #include <arch/bootblock.h> |
| #include <device/pci_ops.h> |
| #include "sandybridge.h" |
| |
| void bootblock_early_northbridge_init(void) |
| { |
| uint32_t reg; |
| |
| /* |
| * The "io" variant of the config access is explicitly used to setup the |
| * PCIEXBAR because CONFIG_MMCONF_SUPPORT is set to to true. That way, all |
| * subsequent non-explicit config accesses use MCFG. This code also assumes |
| * that bootblock_northbridge_init() is the first thing called in the non-asm |
| * boot block code. The final assumption is that no assembly code is using the |
| * CONFIG_MMCONF_SUPPORT option to do PCI config accesses. |
| * |
| * The PCIEXBAR is assumed to live in the memory mapped IO space under 4GiB. |
| */ |
| reg = 0; |
| pci_io_write_config32(HOST_BRIDGE, PCIEXBAR + 4, reg); |
| reg = CONFIG_MMCONF_BASE_ADDRESS | 4 | 1; /* 64MiB - 0-63 buses. */ |
| pci_io_write_config32(HOST_BRIDGE, PCIEXBAR, reg); |
| } |