Date: Mon, 02 Aug 1999 22:22:51 +0900 From: Mitsuru IWASAKI <iwasaki@jp.FreeBSD.org> To: Maxim Sobolev <sobomax@altavista.net> Cc: Mike Smith <mike@smith.net.au>, FreeBSD-current@FreeBSD.ORG, iwasaki@jp.freebsd.org Subject: Re: APM related panic Message-ID: <199908021318.WAA14239@tasogare.imasy.or.jp>
next in thread | raw e-mail | index | archive | help
# sorry to break the thread, I'm a digest reader...
Hi,
> > apm0: <APM BIOS> on motherboard
> > apm: APM BIOS version 0102
> > apm: Code16 0xc00f0000, Data 0xc00fdfa0
> > apm: Code entry 0x00008010, Idling CPU enabled, Management enabled
> > apm: CS_limit=0x0, DS_limit=0x0
>
> These limits look pretty suspect, although the code segment below looks
> OK.
I suspect too, especially ds limit.
I've seen such bogus 1.2 APM BIOSes before. I hope attached patch
help you (for /sys/i386/apm/apm.c).
P.S.
Thank you for enhanced APM code, mike. I had enjoy last week end to
study the new code. Some of my concerns about APM gone :-)
--- apm.c- Mon Aug 2 21:31:20 1999
+++ apm.c Mon Aug 2 21:49:52 1999
@@ -773,6 +773,30 @@
sc->bios.seg.code16.limit = 0xffff;
sc->bios.seg.data.limit = 0xffff;
}
+
+ /*
+ * Segment limits fixup:
+ * Some bogus APM V1.1 (even if V1.2) BIOSes do not return
+ * any size limits in the registers they are supposed to.
+ * if we see zero limits here, we assume that means they
+ * should be 64k.
+ */
+
+ /* code segment (16 bit) */
+ if (sc->bios.seg.code16.limit == 0) {
+#ifdef APM_DEBUG
+ printf("apm_probe: APM bios gave zero len code16, pegged to 64K\n");
+#endif
+ sc->bios.seg.code16.limit = 0xffff;
+ }
+ /* data segment */
+ if (sc->bios.seg.data.limit == 0) {
+#ifdef APM_DEBUG
+ printf("apm_probe: APM bios gave zero len data, tentative 64K\n");
+#endif
+ sc->bios.seg.data.limit = 0xffff;
+ }
+
return(0);
}
To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-current" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199908021318.WAA14239>