Let VCHIQ know which page list format to use

VCHIQ bulk transfers on Pi 4 use a different page list format, in order
to allow for full use of the larger 36bit physical address space. Add a
flags word to the VCHIQ HAL device so that we can let the VCHIQ module
know what page list format it should use for the machine we're running
on.

hdr/StaticWS

@@ -70,8 +70,11 @@ HALDevice_VCHIQARMToVCOffset     # 4
 HALDevice_VCHIQVCDoorbell        # 4 ; Doorbell to interrupt VC
 HALDevice_VCHIQARMDoorbell       # 4 ; Doorbell to interrupt us
 HALDevice_VCHIQInitVC            # 4
+HALDevice_VCHIQFlags             # 4
 HALDevice_VCHIQ_Size             * :INDEX: @
 
+VCHIQFlag_Use36bitAddrs          * 1
+
 ; Device-specific struct for the VDU device
 
                         ^ 0

s/VCHIQ

@@ -68,7 +68,7 @@ VCHIQ_Dev
         HALDeviceField Type,               HALDeviceType_Comms + HALDeviceComms_InterProc
         HALDeviceField ID,                 HALDeviceID_InterProc_VCHIQ
         HALDeviceField Location,           HALDeviceBus_Sys + HALDeviceSysBus_AHB ; Guess
-        HALDeviceField Version,            0
+        HALDeviceField Version,            1 ; API 0.1
         HALDeviceField Description,        VCHIQ_Description
         HALDeviceField Address,            0
         HALDeviceField Reserved1,          0
@@ -84,6 +84,7 @@ VCHIQ   HALDeviceField ARMToVCOffset,      0 ; filled in later
 VCHIQ   HALDeviceField VCDoorbell,         VCHIQ_VCDoorbell
 VCHIQ   HALDeviceField ARMDoorbell,        VCHIQ_ARMDoorbell
 VCHIQ   HALDeviceField InitVC,             VCHIQ_InitVC
+VCHIQ   HALDeviceField Flags,              0 ; filled in later
         ASSERT  . - %A0 = HALDevice_VCHIQ_Size
 
 VCHIQ_Description
@@ -102,6 +103,12 @@ VCHIQ_InitDevices ROUT
         LDR     a1, FB_CacheMode
         STR     a1, [a2, #HALDevice_VCHIQARMToVCOffset]
         MOV     a1, #0
+        CPUDetect ip
+        ; Raspberry Pi 4 / BCM2838 uses a different page list format to allow
+        ; for a 36bit physical address range
+        ORRHI   a1, a1, #VCHIQFlag_Use36bitAddrs
+        STR     a1, [a2, #HALDevice_VCHIQFlags]
+        MOV     a1, #0
         MOV     lr, pc
         LDR     pc, OSentries+4*OS_AddDevice
         EXIT