Syncboot/gnu-efi/apps/route80h.c

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#include <efi.h>
#include <efilib.h>
/* this example program changes the Reserved Page Route (RPR) bit on ICH10's General
* Control And Status Register (GCS) from LPC to PCI. In practical terms, it routes
* outb to port 80h to the PCI bus. */
#define GCS_OFFSET_ADDR 0x3410
#define GCS_RPR_SHIFT 2
#define GCS_RPR_PCI 1
#define GCS_RPR_LPC 0
#define VENDOR_ID_INTEL 0x8086
#define DEVICE_ID_LPCIF 0x3a16
#define DEVICE_ID_COUGARPOINT_LPCIF 0x1c56
static EFI_HANDLE ImageHandle;
typedef struct {
uint16_t vendor_id; /* 00-01 */
uint16_t device_id; /* 02-03 */
char pad[0xEB]; /* 04-EF */
uint32_t rcba; /* F0-F3 */
uint32_t reserved[3]; /* F4-FF */
} lpcif_t;
static inline void set_bit(volatile uint32_t *flag, int bit, int value)
{
uint32_t val = *flag;
Print(L"current value is 0x%2x\n", val);
if (value) {
val |= (1 << bit);
} else {
val &= ~(1 << bit);
}
Print(L"setting value to 0x%2x\n", val);
*flag = val;
val = *flag;
Print(L"new value is 0x%2x\n", val);
}
static int is_device(EFI_PCI_IO *pciio, uint16_t vendor_id, uint16_t device_id)
{
lpcif_t lpcif;
EFI_STATUS rc;
rc = uefi_call_wrapper(pciio->Pci.Read, 5, pciio, EfiPciIoWidthUint16, 0, 2, &lpcif);
if (EFI_ERROR(rc))
return 0;
if (vendor_id == lpcif.vendor_id && device_id == lpcif.device_id)
return 1;
return 0;
}
static EFI_STATUS find_pci_device(uint16_t vendor_id, uint16_t device_id,
EFI_PCI_IO **pciio)
{
EFI_STATUS rc;
EFI_HANDLE *Handles;
UINTN NoHandles, i;
if (!pciio)
return EFI_INVALID_PARAMETER;
rc = LibLocateHandle(ByProtocol, &PciIoProtocol, NULL, &NoHandles,
&Handles);
if (EFI_ERROR(rc))
return rc;
for (i = 0; i < NoHandles; i++) {
void *pciio_tmp = NULL;
rc = uefi_call_wrapper(BS->OpenProtocol, 6, Handles[i],
&PciIoProtocol, &pciio_tmp, ImageHandle,
NULL, EFI_OPEN_PROTOCOL_GET_PROTOCOL);
if (EFI_ERROR(rc))
continue;
*pciio = pciio_tmp;
if (!is_device(*pciio, vendor_id, device_id)) {
*pciio = NULL;
continue;
}
return EFI_SUCCESS;
}
return EFI_NOT_FOUND;
}
EFI_STATUS
efi_main (EFI_HANDLE image_handle, EFI_SYSTEM_TABLE *systab)
{
InitializeLib(image_handle, systab);
EFI_PCI_IO *pciio = NULL;
lpcif_t lpcif;
EFI_STATUS rc = EFI_SUCCESS;
struct {
uint16_t vendor;
uint16_t device;
} devices[] = {
{ VENDOR_ID_INTEL, DEVICE_ID_LPCIF },
{ VENDOR_ID_INTEL, DEVICE_ID_COUGARPOINT_LPCIF },
{ 0, 0 }
};
int i;
ImageHandle = image_handle;
for (i = 0; devices[i].vendor != 0; i++) {
rc = find_pci_device(devices[i].vendor, devices[i].device, &pciio);
if (EFI_ERROR(rc))
continue;
}
if (rc == EFI_NOT_FOUND) {
Print(L"Device not found.\n");
return rc;
} else if (EFI_ERROR(rc)) {
return rc;
}
rc = uefi_call_wrapper(pciio->Pci.Read, 5, pciio, EfiPciIoWidthUint32,
EFI_FIELD_OFFSET(lpcif_t, rcba), 1, &lpcif.rcba);
if (EFI_ERROR(rc))
return rc;
if (!(lpcif.rcba & 1)) {
Print(L"rcrb is not mapped, cannot route port 80h\n");
return EFI_UNSUPPORTED;
}
lpcif.rcba &= ~1UL;
Print(L"rcba: 0x%8x\n", lpcif.rcba, lpcif.rcba);
set_bit((uint32_t *)(intptr_t)(lpcif.rcba + GCS_OFFSET_ADDR),
GCS_RPR_SHIFT, GCS_RPR_PCI);
return EFI_SUCCESS;
}