By default the legacy segments C/D/E/F do not decode to system RAM. Turn on the decode via Programmable Attribute Map (PAM) registers so that we can write configuration tables in the F segment.
Signed-off-by: Bin Meng <[email protected]> Acked-by: Simon Glass <[email protected]> --- Changes in v2: None arch/x86/cpu/qemu/pci.c | 20 ++++++++++++++++++++ arch/x86/include/asm/arch-qemu/qemu.h | 6 ++++++ 2 files changed, 26 insertions(+) diff --git a/arch/x86/cpu/qemu/pci.c b/arch/x86/cpu/qemu/pci.c index ac9c056..2f4ba17 100644 --- a/arch/x86/cpu/qemu/pci.c +++ b/arch/x86/cpu/qemu/pci.c @@ -7,6 +7,8 @@ #include <common.h> #include <pci.h> #include <pci_rom.h> +#include <asm/pci.h> +#include <asm/arch/qemu.h> DECLARE_GLOBAL_DATA_PTR; @@ -50,6 +52,8 @@ int board_pci_post_scan(struct pci_controller *hose) ulong start; pci_dev_t bdf; struct pci_device_id graphic_card[] = { { 0x1234, 0x1111 } }; + u16 device; + int pam, i; /* * QEMU emulated graphic card shows in the PCI configuration space with @@ -67,5 +71,21 @@ int board_pci_post_scan(struct pci_controller *hose) debug("BIOS ran in %lums\n", get_timer(start)); } + /* + * i440FX and Q35 chipset have different PAM register offset, but with + * the same bitfield layout. Here we determine the offset based on its + * PCI device ID. + */ + device = x86_pci_read_config16(PCI_BDF(0, 0, 0), PCI_DEVICE_ID); + pam = (device == PCI_DEVICE_ID_INTEL_82441) ? I440FX_PAM : Q35_PAM; + + /* + * Initialize Programmable Attribute Map (PAM) Registers + * + * Configure legacy segments C/D/E/F to system RAM + */ + for (i = 0; i < PAM_NUM; i++) + x86_pci_write_config8(PCI_BDF(0, 0, 0), pam + i, PAM_RW); + return ret; } diff --git a/arch/x86/include/asm/arch-qemu/qemu.h b/arch/x86/include/asm/arch-qemu/qemu.h index 8d7e986..7a9901d 100644 --- a/arch/x86/include/asm/arch-qemu/qemu.h +++ b/arch/x86/include/asm/arch-qemu/qemu.h @@ -7,6 +7,12 @@ #ifndef _ARCH_QEMU_H_ #define _ARCH_QEMU_H_ +/* Programmable Attribute Map (PAM) Registers */ +#define I440FX_PAM 0x59 +#define Q35_PAM 0x90 +#define PAM_NUM 7 +#define PAM_RW 0x33 + /* I/O Ports */ #define CMOS_ADDR_PORT 0x70 #define CMOS_DATA_PORT 0x71 -- 1.8.2.1 _______________________________________________ U-Boot mailing list [email protected] http://lists.denx.de/mailman/listinfo/u-boot
