t2 engine svn checkout

platform/platformCPUInfo.asm

@@ -0,0 +1,96 @@
+;-----------------------------------------------------------------------------
+; V12 Engine
+;
+; Copyright (c) 2001 GarageGames.Com
+; Portions Copyright (c) 2001 by Sierra Online, Inc.
+;-----------------------------------------------------------------------------
+
+
+segment .text
+
+; this is a nice macro Rick
+; syntax: export_fn <function name>
+%macro export_fn 1
+   %ifdef LINUX
+   ; No underscore needed for ELF object files
+   global %1
+   %1:
+   %else
+   global _%1
+   _%1:
+   %endif
+%endmacro
+
+; so is this
+;%define arg(x) [esp+(x*4)]
+
+; void isCPUIDSupported(char *vendor, U32 *properties, U32 *processor);
+export_fn isCPUIDSupported
+
+;   mov          ebp, esp
+   push         ebp
+   push         ebx
+   push         edx
+   push         ecx
+;   mov           ecx, arg(1)
+;   mov           edx, arg(2)
+;   mov           eax, arg(3)
+   pushfd
+   pushfd                        ; save EFLAGS to stack
+   pop          eax              ; move EFLAGS into EAX
+   mov          ebx, eax
+   xor          eax, 0x200000    ; flip bit 21
+   push         eax
+   popfd                         ; restore EFLAGS
+   pushfd
+   pop          eax
+   cmp          eax, ebx
+   jz           EXIT             ; doesn't support CPUID instruction
+
+   ;
+   ; get vendor information using CPUID eax == 0
+   xor          eax, eax
+   cpuid
+
+;   mov          dword [vendor], ebx
+;   mov          dword [vendor+4], edx
+;   mov          dword [vendor+8], ecx
+   mov          dword [esp+8], ebx
+   mov          dword [esp+12], edx
+   mov          dword [esp+16], ecx
+   popfd
+   pop          ecx
+   pop          edx
+   pop          ebx
+   leave
+;   pop          ebp
+;   mov          esp, ebp
+   ret
+;jz EXIT
+   ; get generic extended CPUID info
+   mov          eax, 1
+   cpuid                         ; eax=1, so cpuid queries feature information
+
+   and          eax, 0x0FF0
+   mov          [esp+20], eax    ; just store the model bits
+   mov          [esp+16], edx
+
+   ; want to check for 3DNow(tm).  need to see if extended cpuid functions present.
+   mov          eax, 0x80000000
+   cpuid
+   cmp          eax, 0x80000000
+   jbe          MAYBE_3DLATER
+   mov          eax, 0x80000001
+   cpuid
+   and          edx, 0x80000000  ; 3DNow if bit 31 set -> put bit in our properties
+   or           [esp+16], edx
+MAYBE_3DLATER:
+
+
+EXIT:
+   popfd
+   pop          ecx
+   pop          edx
+   pop          ebx
+   ret
+