/* $OpenBSD: cpuprobe.c,v 1.3 2022/07/07 00:56:46 daniel Exp $ */ /* * Copyright (c) 2004 Tom Cosgrove * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ #include #include #include "libsa.h" int amd64_supported; static int cpu_family, cpu_model, cpu_stepping; static int psl_check; static u_int32_t feature_ecx, feature_edx, feature_amd; static char cpu_brandstr[48]; /* Includes term NUL byte */ static char cpu_vendor[13]; /* 12 chars plus NUL term */ /* * cpuid instruction. request in eax, result in eax, ebx, ecx, edx. * requires caller to provide u_int32_t regs[4] array. */ u_int32_t cpuid(u_int32_t eax, u_int32_t *regs) { __asm volatile( "cpuid\n\t" "movl %%eax, 0(%2)\n\t" "movl %%ebx, 4(%2)\n\t" "movl %%ecx, 8(%2)\n\t" "movl %%edx, 12(%2)\n\t" : "=a" (eax) : "0" (eax), "S" (regs) : "bx", "cx", "dx"); return eax; } void cpuprobe(void) { u_int32_t cpuid_max, extended_max; u_int32_t regs[4]; /* * The following is a simple check to see if cpuid is supported. * We try to toggle bit 21 (PSL_ID) in eflags. If it works, then * cpuid is supported. If not, there's no cpuid, and we don't * try it (don't want /boot to get an invalid opcode exception). */ __asm volatile( "pushfl\n\t" "popl %2\n\t" "xorl %2, %0\n\t" "pushl %0\n\t" "popfl\n\t" "pushfl\n\t" "popl %0\n\t" "xorl %2, %0\n\t" /* If %2 == %0, no cpuid */ : "=r" (psl_check) : "0" (PSL_ID), "r" (0) : "cc"); if (psl_check == PSL_ID) { /* cpuid supported */ cpuid_max = cpuid(0, regs); /* Highest std call */ bcopy(®s[1], cpu_vendor, sizeof(regs[1])); bcopy(®s[3], cpu_vendor + 4, sizeof(regs[3])); bcopy(®s[2], cpu_vendor + 8, sizeof(regs[2])); cpu_vendor[sizeof(cpu_vendor) - 1] = '\0'; if (cpuid_max >= 1) { u_int32_t id; id = cpuid(1, regs); /* Get basic info */ cpu_stepping = id & 0x000000f; cpu_model = (id >> 4) & 0x0000000f; cpu_family = (id >> 8) & 0x0000000f; feature_ecx = regs[2]; feature_edx = regs[3]; } extended_max = cpuid(0x80000000, regs); /* Highest ext */ if (extended_max >= 0x80000001) { cpuid(0x80000001, regs); feature_amd = regs[3]; if (feature_amd & CPUID_LONG) amd64_supported = 1; } cpu_brandstr[0] = '\0'; if (extended_max >= 0x80000004) { u_int32_t brand_ints[12]; cpuid(0x80000002, brand_ints); cpuid(0x80000003, brand_ints + 4); cpuid(0x80000004, brand_ints + 8); bcopy(brand_ints, cpu_brandstr, sizeof(cpu_brandstr) - 1); cpu_brandstr[sizeof(cpu_brandstr) - 1] = '\0'; } } printf("%s", amd64_supported ? " amd64" : " i386"); } void dump_cpuinfo(void) { printf("\"%s\", family %d, model %d, step %d\n", cpu_vendor, cpu_family, cpu_model, cpu_stepping); if (*cpu_brandstr) printf("%s\n", cpu_brandstr); printf("features: ecx 0x%x, edx 0x%x, amd 0x%x\n", feature_ecx, feature_edx, feature_amd); printf("psl_check: 0x%x\n", psl_check); }