Author: wmb Date: 2009-12-06 07:49:17 +0100 (Sun, 06 Dec 2009) New Revision: 1540
Modified: dev/ramdisk.fth Log: Ramdisk driver - moved base address and size assumptions out of the driver code; they can be set externally.
Modified: dev/ramdisk.fth =================================================================== --- dev/ramdisk.fth 2009-12-06 06:18:01 UTC (rev 1539) +++ dev/ramdisk.fth 2009-12-06 06:49:17 UTC (rev 1540) @@ -1,23 +1,29 @@ \ See license at end of file purpose: Block-method additions to subrange.fth device to make a RAMdisk device
-0 0 " b000000" " /" begin-package - " ramdisk" device-name - h# 3800000 constant /device +\ Define ramdisk-base before loading this file
+0 0 ramdisk-base (u.) " /" begin-package + +" ramdisk" device-name +0 value /device \ Range size, set later with set-size + external -\ /device must be defined externally as the length of the subrange -\ my-space is the base of the subrange my-address my-space /device reg
0 value offset \ seek pointer
+\ Reduce adr,len as necessary to fit within the actual device size : clip-size ( adr len -- adr actual ) offset + /device min offset - ( adr actual ) ; + +\ Update the seek pointer to reflect the result of the previous read or write : update-ptr ( actual -- actual ) dup offset + to offset ;
external + +\ Standard interface methods for a byte-granularity device : open ( -- flag ) 0 to offset true ; : close ( -- ) ;
@@ -36,9 +42,12 @@ tuck offset my-space + swap move ( actual ) update-ptr ; -: size ( -- d ) /device 0 ; +: size ( -- d ) /device u>d ;
+\ Device-specific method to set the device size when it is known +: set-size ( d -- ) drop to /device ;
+\ Standard interface methods for block-granularity access h# 200 value block-size : #blocks ( -- n ) /device block-size / ; : read-blocks ( adr block# #blocks -- actual-#blocks )