/* SPDX-License-Identifier: GPL-2.0-only */ #include #include #include #include #include #include "q35.h" static void bootblock_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 acceses. * * The PCIEXBAR is assumed to live in the memory mapped IO space under * 4GiB. */ reg = 0; pci_io_write_config32(PCI_DEV(0,0,0), D0F0_PCIEXBAR_HI, reg); reg = CONFIG_MMCONF_BASE_ADDRESS | 1; /* 256MiB - 0-255 buses. */ pci_io_write_config32(PCI_DEV(0,0,0), D0F0_PCIEXBAR_LO, reg); /* MCFG is now active. If it's not qemu was started for machine PC */ if (CONFIG(BOOTBLOCK_CONSOLE) && (pci_read_config32(PCI_DEV(0, 0, 0), D0F0_PCIEXBAR_LO) != (CONFIG_MMCONF_BASE_ADDRESS | 1))) die("You must run qemu for machine Q35 (-M q35)"); } static void bootblock_southbridge_init(void) { enable_spi_prefetching_and_caching(); /* Enable RCBA */ pci_write_config32(PCI_DEV(0, 0x1f, 0), RCBA, (uintptr_t)DEFAULT_RCBA | 1); } void bootblock_soc_init(void) { bootblock_northbridge_init(); bootblock_southbridge_init(); }