2000/1221/pc/apm.c (diff list | history)

pc/apm.c on 2000/1018
2000/1018		/*
2000/1019		* 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.
2000/1018		*/ #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.
2000/1019		* however, knowing this much about the memory unit * means that the memory unit need not know anything * about us.
2000/1018		* * 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 void loadgdt(void) { ulong x; ushort ptr[3]; ptr[0] = sizeof(m->gdt); x = (ulong)m->gdt; ptr[1] = x & 0xFFFF; ptr[2] = (x>>16) & 0xFFFF; lgdt(ptr); } 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){ // if(n == 5 && strncmp(a, "ether", 5) == 0){ // ether589reset(); // return 5; // } 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; /* * 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; }
2000/1019		/* * 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;
2000/1018		/* * 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); loadgdt(); addarchfile("apm", 0660, apmread, apmwrite);
2000/1221		doze = halt;
2000/1018		print("apm0: configured cbase %.8lux off %.8lux\n", ax<<4, ebx); return; }