gnu-efi/apps/route80h.c

   1 #include <efi.h>
   2 #include <efilib.h>
   3
   4 /* this example program changes the Reserved Page Route (RPR) bit on ICH10's General
   5  * Control And Status Register (GCS) from LPC to PCI.  In practical terms, it routes
   6  * outb to port 80h to the PCI bus. */
   7
   8 #define GCS_OFFSET_ADDR 0x3410
   9 #define GCS_RPR_SHIFT 2
  10 #define GCS_RPR_PCI 1
  11 #define GCS_RPR_LPC 0
  12
  13 #define VENDOR_ID_INTEL 0x8086
  14 #define DEVICE_ID_LPCIF 0x3a16
  15 #define DEVICE_ID_COUGARPOINT_LPCIF 0x1c56
  16
  17 static EFI_HANDLE ImageHandle;
  18
  19 typedef struct {
  20         uint16_t vendor_id;     /* 00-01 */
  21         uint16_t device_id;     /* 02-03 */
  22         char pad[0xEB];         /* 04-EF */
  23         uint32_t rcba;          /* F0-F3 */
  24         uint32_t reserved[3];   /* F4-FF */
  25 } lpcif_t;
  26
  27 static inline void set_bit(volatile uint32_t *flag, int bit, int value)
  28 {
  29         uint32_t val = *flag;
  30         Print(L"current value is 0x%2x\n", val);
  31
  32         if (value) {
  33                 val |= (1 << bit);
  34         } else {
  35                 val &= ~(1 << bit);
  36         }
  37         Print(L"setting value to 0x%2x\n", val);
  38         *flag = val;
  39         val = *flag;
  40         Print(L"new value is 0x%2x\n", val);
  41 }
  42
  43 static int is_device(EFI_PCI_IO *pciio, uint16_t vendor_id, uint16_t device_id)
  44 {
  45         lpcif_t lpcif;
  46         EFI_STATUS rc;
  47
  48         rc = uefi_call_wrapper(pciio->Pci.Read, 5, pciio, EfiPciIoWidthUint16, 0, 2, &lpcif);
  49         if (EFI_ERROR(rc))
  50                 return 0;
  51
  52         if (vendor_id == lpcif.vendor_id && device_id == lpcif.device_id)
  53                 return 1;
  54         return 0;
  55 }
  56
  57 static EFI_STATUS find_pci_device(uint16_t vendor_id, uint16_t device_id,
  58                                 EFI_PCI_IO **pciio)
  59 {
  60         EFI_STATUS rc;
  61         EFI_HANDLE *Handles;
  62         UINTN NoHandles, i;
  63
  64         if (!pciio)
  65                 return EFI_INVALID_PARAMETER;
  66
  67         rc = LibLocateHandle(ByProtocol, &PciIoProtocol, NULL, &NoHandles,
  68                              &Handles);
  69         if (EFI_ERROR(rc))
  70                 return rc;
  71
  72         for (i = 0; i < NoHandles; i++) {
  73                 void *pciio_tmp = NULL;
  74                 rc = uefi_call_wrapper(BS->OpenProtocol, 6, Handles[i],
  75                                     &PciIoProtocol, &pciio_tmp, ImageHandle,
  76                                     NULL, EFI_OPEN_PROTOCOL_GET_PROTOCOL);
  77                 if (EFI_ERROR(rc))
  78                         continue;
  79                 *pciio = pciio_tmp;
  80                 if (!is_device(*pciio, vendor_id, device_id)) {
  81                         *pciio = NULL;
  82                         continue;
  83                 }
  84
  85                 return EFI_SUCCESS;
  86         }
  87         return EFI_NOT_FOUND;
  88 }
  89
  90 EFI_STATUS
  91 efi_main (EFI_HANDLE image_handle, EFI_SYSTEM_TABLE *systab)
  92 {
  93         InitializeLib(image_handle, systab);
  94         EFI_PCI_IO *pciio = NULL;
  95         lpcif_t lpcif;
  96         EFI_STATUS rc = EFI_SUCCESS;
  97         struct {
  98                 uint16_t vendor;
  99                 uint16_t device;
 100         } devices[] = {
 101                 { VENDOR_ID_INTEL, DEVICE_ID_LPCIF },
 102                 { VENDOR_ID_INTEL, DEVICE_ID_COUGARPOINT_LPCIF },
 103                 { 0, 0 }
 104         };
 105         int i;
 106
 107         ImageHandle = image_handle;
 108         for (i = 0; devices[i].vendor != 0; i++) {
 109                 rc = find_pci_device(devices[i].vendor, devices[i].device, &pciio);
 110                 if (EFI_ERROR(rc))
 111                         continue;
 112         }
 113
 114         if (rc == EFI_NOT_FOUND) {
 115                 Print(L"Device not found.\n");
 116                 return rc;
 117         } else if (EFI_ERROR(rc)) {
 118                 return rc;
 119         }
 120
 121         rc = uefi_call_wrapper(pciio->Pci.Read, 5, pciio, EfiPciIoWidthUint32,
 122                 EFI_FIELD_OFFSET(lpcif_t, rcba), 1, &lpcif.rcba);
 123         if (EFI_ERROR(rc))
 124                 return rc;
 125         if (!(lpcif.rcba & 1)) {
 126                 Print(L"rcrb is not mapped, cannot route port 80h\n");
 127                 return EFI_UNSUPPORTED;
 128         }
 129         lpcif.rcba &= ~1UL;
 130
 131         Print(L"rcba: 0x%8x\n", lpcif.rcba, lpcif.rcba);
 132         set_bit((uint32_t *)(intptr_t)(lpcif.rcba + GCS_OFFSET_ADDR),
 133                      GCS_RPR_SHIFT, GCS_RPR_PCI);
 134
 135         return EFI_SUCCESS;
 136 }