1 /* 2 * Copyright (c) 1998 Michael Smith <msmith@freebsd.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27 #include <sys/cdefs.h> 28 29 #include <stand.h> 30 #include <machine/psl.h> 31 #include <machine/cpufunc.h> 32 #include <machine/specialreg.h> 33 34 /* 35 * Check to see if this CPU supports long mode. 36 */ 37 int 38 bi_checkcpu(void) 39 { 40 unsigned long flags; 41 unsigned int regs[4]; 42 unsigned int maxeax; 43 unsigned int max_maxeax = 0x100; 44 unsigned int stdfeatures = 0, xtdfeatures = 0; 45 int amd64 = 0; 46 47 /* Check for presence of "cpuid". */ 48 #if defined(__LP64__) 49 flags = read_rflags(); 50 write_rflags(flags ^ PSL_ID); 51 if (!((flags ^ read_rflags()) & PSL_ID)) 52 return (0); 53 #else 54 flags = read_eflags(); 55 write_eflags(flags ^ PSL_ID); 56 if (!((flags ^ read_eflags()) & PSL_ID)) 57 return (0); 58 #endif /* __LP64__ */ 59 60 /* Fetch the vendor string. */ 61 do_cpuid(0, regs); 62 maxeax = regs[0]; 63 64 /* 65 * Limit the range in case of weird hardware 66 */ 67 if (maxeax > max_maxeax) 68 maxeax = max_maxeax; 69 if (maxeax < 1) 70 return (0); 71 else { 72 do_cpuid(1, regs); 73 stdfeatures = regs[3]; 74 } 75 76 /* Has to support AMD features. */ 77 do_cpuid(0x80000000, regs); 78 if (regs[0] & 0x80000000) { 79 maxeax = regs[0]; 80 max_maxeax = 0x80000100; 81 if (maxeax > max_maxeax) 82 maxeax = max_maxeax; 83 if (maxeax >= 0x80000001) { 84 do_cpuid(0x80000001, regs); 85 xtdfeatures = regs[3]; 86 } 87 } 88 89 /* Check for long mode. */ 90 if (xtdfeatures & AMDID_LM) 91 amd64++; 92 93 /* Check for FPU. */ 94 if ((stdfeatures & CPUID_FPU) == 0) 95 amd64 = 0; 96 97 if ((stdfeatures & CPUID_TSC) == 0) 98 amd64 = 0; 99 100 if ((stdfeatures & CPUID_MSR) == 0) 101 amd64 = 0; 102 103 if ((stdfeatures & CPUID_PAE) == 0) 104 amd64 = 0; 105 106 if ((stdfeatures & CPUID_CX8) == 0) 107 amd64 = 0; 108 109 if ((stdfeatures & CPUID_PGE) == 0) 110 amd64 = 0; 111 112 if ((stdfeatures & CPUID_CLFSH) == 0) 113 amd64 = 0; 114 115 if ((stdfeatures & CPUID_MMX) == 0) 116 amd64 = 0; 117 118 if ((stdfeatures & CPUID_FXSR) == 0) 119 amd64 = 0; 120 121 if ((stdfeatures & CPUID_SSE) == 0) 122 amd64 = 0; 123 124 if ((stdfeatures & CPUID_SSE2) == 0) 125 amd64 = 0; 126 127 return (amd64); 128 } 129 130 void 131 bi_isadir(void) 132 { 133 int rc; 134 135 if (bi_checkcpu()) 136 rc = setenv("ISADIR", "amd64", 1); 137 else 138 rc = setenv("ISADIR", "", 1); 139 140 if (rc != 0) { 141 printf("Warning: failed to set ISADIR environment " 142 "variable: %d\n", rc); 143 } 144 } 145