Address issue chipsec#249

changed drivers/linux/include/chipsec.h to start from 'C'
added logic to compute ioctl base based upon changes to chipsec.h above

chipsec/helper/linux/helper.py

@@ -82,7 +82,6 @@
 Tiano = efi_compressor.TianoDecompress
 EFI   = efi_compressor.EfiDecompress
 
-
 class MemoryMapping(mmap.mmap):
     """Memory mapping based on Python's mmap.
 
@@ -218,7 +217,7 @@ def init(self, start_driver):
             except BaseException as be:
                 raise OsHelperError("Unable to open chipsec device. Did you run as root/sudo and load the driver?\n %s"%str(be),errno.ENXIO)
 
-            self._ioctl_base = fcntl.ioctl(self.dev_fh, IOCTL_BASE) << 4
+            self._ioctl_base = self.compute_ioctlbase()
 
     def devmem_available(self):
         """Check if /dev/mem is usable.
@@ -297,6 +296,23 @@ def close(self):
             os.close(self.dev_mem)
         self.dev_mem = None
 
+    # code taken from /include/uapi/asm-generic/ioctl.h
+    # by default itype is 'C' see drivers/linux/include/chipsec.h
+    # currently all chipsec ioctl functions are _IOWR
+    # currently all size are pointer
+    def compute_ioctlbase(self,itype = 'C'):
+        #define _IOWR(type,nr,size)	 _IOC(_IOC_READ|_IOC_WRITE,(type),(nr),(_IOC_TYPECHECK(size))) 
+        #define _IOC(dir,type,nr,size) \
+        #    (((dir)  << _IOC_DIRSHIFT) | \ 
+        #    ((type) << _IOC_TYPESHIFT) | \ 
+        #    ((nr)   << _IOC_NRSHIFT) | \ 
+        #    ((size) << _IOC_SIZESHIFT)) 
+        # IOC_READ | _IOC_WRITE is 3 
+        # default _IOC_DIRSHIFT is 30
+        # default _IOC_TYPESHIFT is 8
+        # nr will be 0
+        # _IOC_SIZESHIFT is 16
+        return (3 << 30) | (ord(itype) << 8) | (struct.calcsize(self._pack) << 16)
 
     def ioctl(self, nr, args, *mutate_flag):
         return fcntl.ioctl(self.dev_fh, self._ioctl_base + nr, args)

drivers/linux/include/chipsec.h

@@ -24,28 +24,28 @@ chipsec@intel.com
 #define MSR_IA32_BIOS_UPDT_TRIG 0x79
 #define MSR_IA32_BIOS_SIGN_ID   0x8b
 
-#define IOCTL_BASE                     _IO(0, 0)
-#define IOCTL_RDIO                     _IOWR(0, 0x1, int*)
-#define IOCTL_WRIO                     _IOWR(0, 0x2, int*)
-#define IOCTL_RDPCI                    _IOWR(0, 0x3, int*)
-#define IOCTL_WRPCI                    _IOWR(0, 0x4, int*)
-#define IOCTL_RDMSR                    _IOWR(0, 0x5, int*) 
-#define IOCTL_WRMSR                    _IOWR(0, 0x6, int*) 
-#define IOCTL_CPUID                    _IOWR(0, 0x7, int*) 
-#define IOCTL_GET_CPU_DESCRIPTOR_TABLE _IOWR(0, 0x8, int*)
-#define IOCTL_HYPERCALL                _IOWR(0, 0x9, int*)
-#define IOCTL_SWSMI                    _IOWR(0, 0xA, int*)
-#define IOCTL_LOAD_UCODE_PATCH         _IOWR(0, 0xB, int*)
-#define IOCTL_ALLOC_PHYSMEM            _IOWR(0, 0xC, int*)
-#define IOCTL_GET_EFIVAR               _IOWR(0, 0xD, int*)
-#define IOCTL_SET_EFIVAR               _IOWR(0, 0xE, int*)       
-#define IOCTL_RDCR                     _IOWR(0, 0x10, int*) 
-#define IOCTL_WRCR                     _IOWR(0, 0x11, int*) 
-#define IOCTL_RDMMIO                   _IOWR(0, 0x12, int*)
-#define IOCTL_WRMMIO                   _IOWR(0, 0x13, int*)
-#define IOCTL_VA2PA                    _IOWR(0, 0x14, int*)
-#define IOCTL_MSGBUS_SEND_MESSAGE      _IOWR(0, 0x15, int*)
-#define IOCTL_FREE_PHYSMEM             _IOWR(0, 0x16, int*)
+#define IOCTL_BASE                     _IO('C', 0)
+#define IOCTL_RDIO                     _IOWR('C', 0x1, int*)
+#define IOCTL_WRIO                     _IOWR('C', 0x2, int*)
+#define IOCTL_RDPCI                    _IOWR('C', 0x3, int*)
+#define IOCTL_WRPCI                    _IOWR('C', 0x4, int*)
+#define IOCTL_RDMSR                    _IOWR('C', 0x5, int*) 
+#define IOCTL_WRMSR                    _IOWR('C', 0x6, int*) 
+#define IOCTL_CPUID                    _IOWR('C', 0x7, int*) 
+#define IOCTL_GET_CPU_DESCRIPTOR_TABLE _IOWR('C', 0x8, int*)
+#define IOCTL_HYPERCALL                _IOWR('C', 0x9, int*)
+#define IOCTL_SWSMI                    _IOWR('C', 0xA, int*)
+#define IOCTL_LOAD_UCODE_PATCH         _IOWR('C', 0xB, int*)
+#define IOCTL_ALLOC_PHYSMEM            _IOWR('C', 0xC, int*)
+#define IOCTL_GET_EFIVAR               _IOWR('C', 0xD, int*)
+#define IOCTL_SET_EFIVAR               _IOWR('C', 0xE, int*)       
+#define IOCTL_RDCR                     _IOWR('C', 0x10, int*) 
+#define IOCTL_WRCR                     _IOWR('C', 0x11, int*) 
+#define IOCTL_RDMMIO                   _IOWR('C', 0x12, int*)
+#define IOCTL_WRMMIO                   _IOWR('C', 0x13, int*)
+#define IOCTL_VA2PA                    _IOWR('C', 0x14, int*)
+#define IOCTL_MSGBUS_SEND_MESSAGE      _IOWR('C', 0x15, int*)
+#define IOCTL_FREE_PHYSMEM             _IOWR('C', 0x16, int*)
 
 //
 // SoC IOSF Message Bus constants