From cc7debc7199b3c637ceead92bc103aeb6eb10a38 Mon Sep 17 00:00:00 2001 From: Bin Meng Date: Sun, 24 May 2015 00:12:33 +0800 Subject: x86: qemu: Turn on legacy segments decode 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 Acked-by: Simon Glass --- arch/x86/cpu/qemu/pci.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) (limited to 'arch/x86/cpu') diff --git a/arch/x86/cpu/qemu/pci.c b/arch/x86/cpu/qemu/pci.c index ac9c056e2b..2f4ba1785d 100644 --- a/arch/x86/cpu/qemu/pci.c +++ b/arch/x86/cpu/qemu/pci.c @@ -7,6 +7,8 @@ #include #include #include +#include +#include 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; } -- cgit v1.2.1