[movitz-cvs] CVS update: movitz/losp/x86-pc/pci.lisp

[Frode Vatvedt Fjeld]

Update of /project/movitz/cvsroot/movitz/losp/x86-pc
In directory common-lisp.net:/tmp/cvs-serv31374

Modified Files:
	pci.lisp 
Log Message:
Some basic functions for interfacing the PCI bios32.

Date: Tue Nov 23 14:45:53 2004
Author: ffjeld

Index: movitz/losp/x86-pc/pci.lisp
diff -u movitz/losp/x86-pc/pci.lisp:1.4 movitz/losp/x86-pc/pci.lisp:1.5
--- movitz/losp/x86-pc/pci.lisp:1.4	Sun Nov 14 23:58:02 2004
+++ movitz/losp/x86-pc/pci.lisp	Tue Nov 23 14:45:51 2004
@@ -10,7 +10,7 @@
 ;;;; Author:        Frode Vatvedt Fjeld <frodef at acm.org>
 ;;;; Created at:    Sun Dec 14 22:33:42 2003
 ;;;;                
-;;;; $Id: pci.lisp,v 1.4 2004/11/14 22:58:02 ffjeld Exp $
+;;;; $Id: pci.lisp,v 1.5 2004/11/23 13:45:51 ffjeld Exp $
 ;;;;                
 ;;;;------------------------------------------------------------------
 
@@ -18,13 +18,65 @@
 
 (provide :x86-pc/pci)
 
-(defun find-bios32 ()
+(defun find-bios32-base ()
   (loop for bios32 from #xe0000 to #xffff0 by 16
       if (and (= (memref-int bios32) #x5f32335f)
 	      (loop with checksum = 0
-				    ;; initially (warn "PCI magic found at #x~X" bios32)
 		  as i from 0 below (* 16 (memref-int bios32 :offset 9 :type :unsigned-byte8))
 		  do (incf checksum
 			   (memref-int bios32 :offset i :type :unsigned-byte8))
 		  finally (return (= 0 (ldb (byte 8 0 ) checksum)))))
       return bios32))
+
+(defvar *bios32-base* nil)
+
+(defun init-pci ()
+  (setf *bios32-base*
+    (find-bios32-base))
+  (if (not *bios32-base*)
+      (error "No PCI BIOS32 found.")
+    (let ((entry (memref-int *bios32-base* :offset 4))
+	  (revision (memref-int *bios32-base* :offset 8 :type :unsigned-byte8))
+	  (length (memref-int *bios32-base* :offset 9 :type :unsigned-byte8)))
+      (values entry revision length))))
+
+(defun pci-far-call (address &key (eax 0) (ebx 0) (cs 8))
+  "Make a 'far call' to cs:address with the provided values for eax and ebx.
+Returns the values of registers AL, EBX, ECX, and EDX. (Well, for now only the
+lower 30 bits are actually returned.) The stack discipline is broken during
+this call, so we disable interrupts in a somewhat feeble attempt to avoid trouble."
+  (without-interrupts
+    (with-inline-assembly (:returns :multiple-values)
+      (:load-lexical (:lexical-binding cs) :untagged-fixnum-ecx)
+      (:pushl :ecx)			; Code segment
+      (:load-lexical (:lexical-binding address) :untagged-fixnum-ecx)
+      (:pushl :ecx)			; Code address
+      (:load-lexical (:lexical-binding ebx) :untagged-fixnum-ecx)
+      (:pushl :ecx)			; EBX
+      (:load-lexical (:lexical-binding eax) :untagged-fixnum-ecx)
+      (:movl :ecx :eax)
+      (:popl :ebx)
+      (:call-segment (:esp))
+      (:leal (:esp 8) :esp)
+      (:andl #xff :eax)
+      (:shll 2 :eax)
+      (:shll 2 :ebx)
+      (:shll 2 :ecx)
+      (:shll 2 :edx)
+      (:locally (:movl :ecx (:edi (:edi-offset values) 0)))
+      (:locally (:movl :edx (:edi (:edi-offset values) 4)))
+      (:movl 4 :ecx)
+      (:stc))))
+
+(defun pci-directory (eax &optional (ebx 0))
+  "Calling with '$PCI' should find the PCI directory."
+  (unless *bios32-base*
+    (init-pci))
+  (let ((eax (etypecase eax
+	       ((unsigned-byte 32)
+		eax)
+	       (string
+		(loop for c across eax as i upfrom 0 by 8
+		    summing (ash (char-code c) i))))))
+    (pci-far-call (memref-int *bios32-base* :offset 4)
+		  :eax eax :ebx ebx)))