File: [local] / sys / lib / libkern / arch / sparc / ffs.S (download)
Revision 1.1.1.1 (vendor branch), Tue Mar 4 16:15:13 2008 UTC (16 years, 6 months ago) by nbrk
Branch: OPENBSD_4_2_BASE, MAIN
CVS Tags: jornada-partial-support-wip, HEAD Changes since 1.1: +0 -0 lines
Import of OpenBSD 4.2 release kernel tree with initial code to support
Jornada 720/728, StrongARM 1110-based handheld PC.
At this point kernel roots on NFS and boots into vfs_mountroot() and traps.
What is supported:
- glass console, Jornada framebuffer (jfb) works in 16bpp direct color mode
(needs some palette tweaks for non black/white/blue colors, i think)
- saic, SA11x0 interrupt controller (needs cleanup)
- sacom, SA11x0 UART (supported only as boot console for now)
- SA11x0 GPIO controller fully supported (but can't handle multiple interrupt
handlers on one gpio pin)
- sassp, SSP port on SA11x0 that attaches spibus
- Jornada microcontroller (jmcu) to control kbd, battery, etc throught
the SPI bus (wskbd attaches on jmcu, but not tested)
- tod functions seem work
- initial code for SA-1111 (chip companion) : this is TODO
Next important steps, i think:
- gpio and intc on sa1111
- pcmcia support for sa11x0 (and sa1111 help logic)
- REAL root on nfs when we have PCMCIA support (we may use any of supported pccard NICs)
- root on wd0! (using already supported PCMCIA-ATA)
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/* $OpenBSD: ffs.S,v 1.3 2003/06/02 23:28:09 millert Exp $ */
/* $NetBSD: ffs.S,v 1.2 1994/10/26 06:39:57 cgd Exp $ */
/*
* Copyright (c) 1992, 1993
* The Regents of the University of California. All rights reserved.
*
* This software was developed by the Computer Systems Engineering group
* at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
* contributed to Berkeley.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* Header: ffs.s,v 1.3 92/07/07 00:23:57 torek Exp
*/
#if defined(LIBC_SCCS) && !defined(lint)
#ifdef notdef
.asciz "@(#)ffs.s 8.1 (Berkeley) 6/4/93"
#endif
.asciz "$OpenBSD: ffs.S,v 1.3 2003/06/02 23:28:09 millert Exp $"
#endif /* LIBC_SCCS and not lint */
#include "DEFS.h"
/*
* ffs returns the number of the rightmost bit set in its argument,
* i.e., the lowest value such that (x & (ffs(x) - 1)) is nonzero.
* If no bits are set, ffs returns 0.
*
* We use a table lookup on each byte.
*
* In each section below, %o1 is the current byte (0, 1, 2, or 3).
* The last byte is handled specially: for the first three,
* if that byte is nonzero, we return the table value
* (plus 0, 8, or 16 for the byte number), but for the last
* one, we just return the table value plus 24. This means
* that ffstab[0] must be -24 so that ffs(0) will return 0.
*/
ENTRY(ffs)
#ifdef PIC
PICCY_SET(ffstab, %o2, %o5)
#else
set ffstab, %o2
#endif
andcc %o0, 0xff, %o1 ! get low byte
be,a 1f ! try again if 0
srl %o0, 8, %o0 ! delay slot, get ready for next byte
retl ! return ffstab[%o1]
ldsb [%o2 + %o1], %o0
1:
andcc %o0, 0xff, %o1 ! byte 1 like byte 0...
be,a 2f
srl %o0, 8, %o0 ! (use delay to prepare for byte 2)
ldsb [%o2 + %o1], %o0
retl ! return ffstab[%o1] + 8
add %o0, 8, %o0
2:
andcc %o0, 0xff, %o1
be,a 3f
srl %o0, 8, %o0 ! (prepare for byte 3)
ldsb [%o2 + %o1], %o0
retl ! return ffstab[%o1] + 16
add %o0, 16, %o0
3: ! just return ffstab[%o0] + 24
ldsb [%o2 + %o0], %o0
retl
add %o0, 24, %o0
ffstab:
.byte -24,1,2,1,3,1,2,1,4,1,2,1,3,1,2,1 /* 00-0f */
.byte 5,1,2,1,3,1,2,1,4,1,2,1,3,1,2,1 /* 10-1f */
.byte 6,1,2,1,3,1,2,1,4,1,2,1,3,1,2,1 /* 20-2f */
.byte 5,1,2,1,3,1,2,1,4,1,2,1,3,1,2,1 /* 30-3f */
.byte 7,1,2,1,3,1,2,1,4,1,2,1,3,1,2,1 /* 40-4f */
.byte 5,1,2,1,3,1,2,1,4,1,2,1,3,1,2,1 /* 50-5f */
.byte 6,1,2,1,3,1,2,1,4,1,2,1,3,1,2,1 /* 60-6f */
.byte 5,1,2,1,3,1,2,1,4,1,2,1,3,1,2,1 /* 70-7f */
.byte 8,1,2,1,3,1,2,1,4,1,2,1,3,1,2,1 /* 80-8f */
.byte 5,1,2,1,3,1,2,1,4,1,2,1,3,1,2,1 /* 10-9f */
.byte 6,1,2,1,3,1,2,1,4,1,2,1,3,1,2,1 /* a0-af */
.byte 5,1,2,1,3,1,2,1,4,1,2,1,3,1,2,1 /* b0-bf */
.byte 7,1,2,1,3,1,2,1,4,1,2,1,3,1,2,1 /* c0-cf */
.byte 5,1,2,1,3,1,2,1,4,1,2,1,3,1,2,1 /* d0-df */
.byte 6,1,2,1,3,1,2,1,4,1,2,1,3,1,2,1 /* e0-ef */
.byte 5,1,2,1,3,1,2,1,4,1,2,1,3,1,2,1 /* f0-ff */