/* ______ ___ ___ * /\ _ \ /\_ \ /\_ \ * \ \ \L\ \\//\ \ \//\ \ __ __ _ __ ___ * \ \ __ \ \ \ \ \ \ \ /'__`\ /'_ `\/\`'__\/ __`\ * \ \ \/\ \ \_\ \_ \_\ \_/\ __//\ \L\ \ \ \//\ \L\ \ * \ \_\ \_\/\____\/\____\ \____\ \____ \ \_\\ \____/ * \/_/\/_/\/____/\/____/\/____/\/___L\ \/_/ \/___/ * /\____/ * \_/__/ * By Shawn Hargreaves * shawn@talula.demon.co.uk * http://www.talula.demon.co.uk/allegro/ * * CPU detection routines, by Phil Frisbie. * * Theuzifan improved the support for Cyrix chips. * * Calin Andrian added 3DNow! detection code. * * See readme.txt for copyright information. */ #include "internal.h" char cpu_vendor[16] = "NoVendorName"; int cpu_family = 0; int cpu_model = 0; int cpu_fpu = FALSE; int cpu_mmx = FALSE; int cpu_3dnow = FALSE; int cpu_cpuid = FALSE; /* is_486: * Returns TRUE for 486+, and FALSE for 386. */ static int is_486() { int result; asm ( " pushf ; " /* save EFLAGS */ " popl %%eax ; " /* get EFLAGS */ " movl %%eax, %%ecx ; " /* temp storage EFLAGS */ " xorl $0x40000, %%eax ; " /* change AC bit in EFLAGS */ " pushl %%eax ; " /* put new EFLAGS value on stack */ " popf ; " /* replace current EFLAGS value */ " pushf ; " /* get EFLAGS */ " popl %%eax ; " /* save new EFLAGS in EAX */ " cmpl %%ecx, %%eax ; " /* compare temp and new EFLAGS */ " jz 0f ;" " movl $1, %%eax ; " /* 80486 present */ " jmp 1f ; " " 0: " " movl $0, %%eax ; " /* 80486 not present */ " 1: " " pushl %%ecx ; " /* get original EFLAGS */ " popf ; " /* restore EFLAGS */ : "=a" (result) : : "eax", "ecx", "memory" ); return result; } /* is_386DX: * Returns TRUE for 386DX, and FALSE for 386SX. */ static int is_386DX() { int result; asm ( " movl %%cr0, %%edx ; " /* get CR0 */ " pushl %%edx ; " /* save CR0 */ " andb $0xef, %%dl ; " /* clear bit4 */ " movl %%edx, %%cr0 ; " /* set CR0 */ " movl %%cr0, %%edx ; " /* and read CR0 */ " andb $0x10, %%dl ; " /* bit4 forced high? */ " popl %%edx ; " /* restore reg w/ CR0 */ " movl %%edx, %%cr0 ; " /* restore CR0 */ " movl $1, %%eax ; " /* TRUE, 386DX */ " jz 0f ; " " movl $0, %%eax ; " /* FALSE, 386SX */ " 0: " : "=a" (result) : : "%edx", "memory" ); return result; } /* is_fpu: * Returns TRUE is the CPU has floating point hardware. */ static int is_fpu() { int result; asm ( " fninit ; " " movl $0x5a5a, %%eax ; " " fnstsw %%eax ; " " cmpl $0, %%eax ; " " jne 0f ; " " movl $1, %%eax ; " " jmp 1f ; " " 0: " " movl $0, %%eax ; " " 1:" : "=a" (result) : : "%eax", "memory" ); return result; } /* is_cyrix: * Returns TRUE if this is a Cyrix processor. */ static int is_cyrix() { int result; asm ( " xorw %%ax, %%ax ; " /* clear eax */ " sahf ; " /* bit 1 is always 1 in flags */ " movw $5, %%ax ; " " movw $2, %%bx ; " " div %%bl ; " /* this does not change flags */ " lahf ; " /* get flags */ " cmpb $2, %%ah ; " /* check for change in flags */ " jne 0f ; " /* flags changed not Cyrix */ " movl $1, %%eax ; " /* TRUE Cyrix CPU */ " jmp 1f ; " " 0: " " movl $0, %%eax ; " /* FALSE NON-Cyrix CPU */ " 1: " : "=a" (result) : : "%eax", "%ebx", "memory" ); return result; } /* cx_w: * Writes to a Cyrix register. */ static void cx_w(int index, int value) { enter_critical(); outportb(0x22, index); /* tell CPU which config register */ outportb(0x23, value); /* write to CPU config register */ exit_critical(); } /* cx_r: * Reads from a Cyrix register. */ static char cx_r(int index) { char value; enter_critical(); outportb(0x22, index); /* tell CPU which config register */ value = inportb(0x23); /* read CPU config register */ exit_critical(); return value; } /* cyrix_type: * Detects which type of Cyrix CPU is in use. */ static void cyrix_type() { char orgc2, newc2, orgc3, newc3; int cr2_rw = FALSE, cr3_rw = FALSE, type; type = 0xFF; orgc2 = cx_r(0xC2); /* get current c2 value */ newc2 = orgc2 ^ 4; /* toggle test bit */ cx_w(0xC2, newc2); /* write test value to c2 */ cx_r(0xC0); /* dummy read to change bus */ if (cx_r(0xC2) != orgc2) /* did test bit toggle */ cr2_rw = TRUE; /* yes bit changed */ cx_w(0xC2, orgc2); /* return c2 to original value */ orgc3 = cx_r(0xC3); /* get current c3 value */ newc3 = orgc3 ^ 0x80; /* toggle test bit */ cx_w(0xC3, newc3); /* write test value to c3 */ cx_r(0xC0); /* dummy read to change bus */ if (cx_r(0xC3) != orgc3) /* did test bit change */ cr3_rw = TRUE; /* yes it did */ cx_w(0xC3, orgc3); /* return c3 to original value */ if (((cr2_rw) && (cr3_rw)) || ((!cr2_rw) && (cr3_rw))) { type = cx_r(0xFE); /* DEV ID register ok */ } else if ((cr2_rw) && (!cr3_rw)) { type = 0xFE; /* Cx486S A step */ } else if ((!cr2_rw) && (!cr3_rw)) { type = 0xFD; /* Pre ID Regs. Cx486SLC or DLC */ } if ((type < 0x30) || (type > 0xFC)) { cpu_family = 4; /* 486 class-including 5x86 */ cpu_model = 14; /* Cyrix */ } else if (type < 0x50) { cpu_family = 5; /* Pentium class-6x86 and Media GX */ cpu_model = 14; /* Cyrix */ } else { cpu_family = 6; /* Pentium || class- 6x86MX */ cpu_model = 14; /* Cyrix */ cpu_mmx = TRUE; } } /* is_cpuid_supported: * Checks whether the cpuid instruction is available. */ static int is_cpuid_supported() { int result; asm ( " pushfl ; " /* get extended flags */ " popl %%eax ; " " movl %%eax, %%ebx ; " /* save current flags */ " xorl $0x200000, %%eax ; " /* toggle bit 21 */ " pushl %%eax ; " /* put new flags on stack */ " popfl ; " /* flags updated now in flags */ " pushfl ; " /* get extended flags */ " popl %%eax ; " " xorl %%ebx, %%eax ; " /* if bit 21 r/w then supports cpuid */ " jz 0f ; " " movl $1, %%eax ; " " jmp 1f ; " " 0: " " movl $0, %%eax ; " " 1: " : "=a" (result) : : "%eax", "%ebx", "memory" ); return result; } /* get_cpuid_info: * This is so easy! */ static void get_cpuid_info(long cpuid_levels, long *eax, long *ebx, long *ecx, long *edx) { long a, b, c, d; asm ( " .byte 0x0F, 0xA2 ; " : "=a" (a), "=b" (b), "=c" (c), "=d" (d) : "0" (cpuid_levels) : "memory" ); *eax = a; *ebx = b; *ecx = c; *edx = d; } /* check_cpu: * This is the function to call to set the globals */ void check_cpu() { long cpuid_levels; long vendor_temp[3]; long reg_eax, reg_ebx, reg_ecx, reg_edx; if (is_cpuid_supported()) { cpu_cpuid = TRUE; get_cpuid_info(0, ®_eax, ®_ebx, ®_ecx, ®_edx); cpuid_levels = reg_eax; vendor_temp[0] = reg_ebx; vendor_temp[1] = reg_edx; vendor_temp[2] = reg_ecx; memcpy(cpu_vendor, vendor_temp, 12); if (cpuid_levels > 0) { reg_eax = reg_ebx = reg_ecx = reg_edx = 0; get_cpuid_info(1, ®_eax, ®_ebx, ®_ecx, ®_edx); cpu_family = (reg_eax & 0xF00) >> 8; cpu_model = (reg_eax & 0xF0) >> 4; cpu_fpu = (reg_edx & 1 ? TRUE : FALSE); cpu_mmx = (reg_edx & 0x800000 ? TRUE: FALSE); } get_cpuid_info(0x80000000, ®_eax, ®_ebx, ®_ecx, ®_edx); if ((unsigned long)reg_eax > 0x80000000) { get_cpuid_info(0x80000001, ®_eax, ®_ebx, ®_ecx, ®_edx); cpu_3dnow = (reg_edx & 0x80000000 ? TRUE : FALSE); } if (is_cyrix()) cpu_model = 14; } else { cpu_fpu = is_fpu(); if (!is_486()) { if (is_386DX()) { cpu_family = 3; cpu_model = 0; } else { cpu_family = 3; cpu_model = 1; } } else { if (is_cyrix()) { strcpy(cpu_vendor, "CyrixInstead"); cyrix_type(); } else { cpu_family = 4; cpu_model = 15; } } } }