Import sources from 2011-03-30 iso image

1 files changed, 153 insertions, 0 deletions

diff --git a/sys/src/9/pc/apm.c b/sys/src/9/pc/apm.c
new file mode 100755
index 000000000..65d6c60bc
--- /dev/null
+++ b/sys/src/9/pc/apm.c
@@ -0,0 +1,153 @@
+/*
+ * Interface to Advanced Power Management 1.2 BIOS
+ *
+ * This is, in many ways, a giant hack, and when things settle down 
+ * a bit and standardize, hopefully we can write a driver that deals
+ * more directly with the hardware and thus might be a bit cleaner.
+ * 
+ * ACPI might be the answer, but at the moment this is simpler
+ * and more widespread.
+ */
+
+#include	"u.h"
+#include	"../port/lib.h"
+#include	"mem.h"
+#include	"dat.h"
+#include	"fns.h"
+#include	"io.h"
+#include	"ureg.h"
+
+extern int apmfarcall(ushort, ulong, Ureg*);		/* apmjump.s */
+
+static int
+getreg(ulong *reg, ISAConf *isa, char *name)
+{
+	int i;
+	int nl;
+
+	nl = strlen(name);
+	for(i=0; i<isa->nopt; i++){
+		if(cistrncmp(isa->opt[i], name, nl)==0 && isa->opt[i][nl] == '='){
+			*reg = strtoul(isa->opt[i]+nl+1, nil, 16);
+			return 0;
+		}
+	}
+	return -1;
+}
+
+/*
+ * Segment descriptors look like this.
+ *
+ * d1: [base 31:24] [gran] [is32bit] [0] [unused] [limit 19:16] 
+		[present] [privlev] [type 3:0] [base 23:16]
+ * d0: [base 15:00] [limit 15:00]
+ *
+ * gran is 0 for 1-byte granularity, 1 for 4k granularity
+ * type is 0 for system segment, 1 for code/data.
+ *
+ * clearly we know way too much about the memory unit.
+ * however, knowing this much about the memory unit
+ * means that the memory unit need not know anything
+ * about us.
+ *
+ * what a crock.
+ */
+static void
+setgdt(int sel, ulong base, ulong limit, int flag)
+{
+	if(sel < 0 || sel >= NGDT)
+		panic("setgdt");
+
+	base = (ulong)KADDR(base);
+	m->gdt[sel].d0 = (base<<16) | (limit&0xFFFF);
+	m->gdt[sel].d1 = (base&0xFF000000) | (limit&0x000F0000) |
+			((base>>16)&0xFF) | SEGP | SEGPL(0) | flag;
+}
+
+static	ulong ax, cx, dx, di, ebx, esi;
+static Ureg apmu;
+static long
+apmread(Chan*, void *a, long n, vlong off)
+{
+	if(off < 0)
+		error("badarg");
+
+	if(n+off > sizeof apmu)
+		n = sizeof apmu - off;
+	if(n <= 0)
+		return 0;
+	memmove(a, (char*)&apmu+off, n);
+	return n;
+}
+
+static long
+apmwrite(Chan*, void *a, long n, vlong off)
+{
+	int s;
+	if(off || n != sizeof apmu)
+		error("write a Ureg");
+
+	memmove(&apmu, a, sizeof apmu);
+	s = splhi();
+	apmfarcall(APMCSEL, ebx, &apmu);
+	splx(s);
+	return n;
+}
+
+void
+apmlink(void)
+{
+	ISAConf isa;
+	char *s;
+
+	if(isaconfig("apm", 0, &isa) == 0)
+		return;
+
+/* XXX use realmode() */
+
+	/*
+	 * APM info passed from boot loader.
+	 * Now we need to set up the GDT entries for APM.
+	 *
+	 * AX = 32-bit code segment base address
+	 * EBX = 32-bit code segment offset
+	 * CX = 16-bit code segment base address
+	 * DX = 32-bit data segment base address
+	 * ESI = <16-bit code segment length> <32-bit code segment length> (hi then lo)
+	 * DI = 32-bit data segment length
+	 */
+
+	if(getreg(&ax, &isa, s="ax") < 0
+	|| getreg(&ebx, &isa, s="ebx") < 0
+	|| getreg(&cx, &isa, s="cx") < 0
+	|| getreg(&dx, &isa, s="dx") < 0
+	|| getreg(&esi, &isa, s="esi") < 0
+	|| getreg(&di, &isa, s="di") < 0){
+		print("apm: missing register %s\n", s);
+		return;
+	}
+
+	/*
+	 * The NEC Versa SX bios does not report the correct 16-bit code
+	 * segment length when loaded directly from mbr -> 9load (as compared
+	 * with going through ld.com).  We'll make both code segments 64k-1 bytes.
+	 */
+	esi = 0xFFFFFFFF;
+
+	/*
+	 * We are required by the BIOS to set up three consecutive segments,
+	 * one for the APM 32-bit code, one for the APM 16-bit code, and 
+	 * one for the APM data.  The BIOS handler uses the code segment it
+	 * get called with to determine the other two segment selector.
+	 */
+	setgdt(APMCSEG, ax<<4, ((esi&0xFFFF)-1)&0xFFFF, SEGEXEC|SEGR|SEGD);
+	setgdt(APMCSEG16, cx<<4, ((esi>>16)-1)&0xFFFF, SEGEXEC|SEGR);
+	setgdt(APMDSEG, dx<<4, (di-1)&0xFFFF, SEGDATA|SEGW|SEGD);
+
+	addarchfile("apm", 0660, apmread, apmwrite);
+
+print("apm0: configured cbase %.8lux off %.8lux\n", ax<<4, ebx);
+
+	return;
+}
+