implemented the get_cpuid() function in libroot and added a new kernel app 'cpuinfo'

git-svn-id: file:///srv/svn/repos/haiku/trunk/current@1582 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/kernel/libroot/os/arch/x86/Jamfile

@@ -1,3 +1,9 @@
 SubDir OBOS_TOP src kernel libroot os arch x86 ;
 
-KernelObjects atomic.S ;
+KernelObjects
+	<$(SOURCE_GRIST)>atomic.S
+	<$(SOURCE_GRIST)>cpuid.S
+	:
+	-fPIC -DPIC
+	;
+

src/kernel/libroot/os/arch/x86/cpuid.S

@@ -0,0 +1,37 @@
+/*
+** Copyright 2001, Travis Geiselbrecht. All rights reserved.
+** Distributed under the terms of the NewOS License.
+*/
+
+#define FUNCTION(x) .global x; .type x,@function; x
+
+.text
+
+/* void cpuid(unsigned int eax_value, unsigned int *return_data) */
+FUNCTION(cpuid):
+ 	pushl	%ebx
+ 	pushl	%edi
+ 	movl	12(%esp),%eax	/* first arg sets up eax */
+ 	movl	16(%esp),%edi	/* second arg points to the return area */
+ 	cpuid
+ 	movl	%eax,0(%edi)	/* copy the regs into the return area */
+ 	movl	%ebx,4(%edi)	/* ... */
+ 	movl	%ecx,8(%edi)	/* ... */
+ 	movl	%edx,12(%edi)	/* ... */
+ 	popl	%edi
+ 	popl	%ebx
+ 	ret
+
+
+/* unsigned int get_eflags(void) */
+FUNCTION(get_eflags):
+ 	pushfl
+ 	popl	%eax
+ 	ret
+
+
+/* void set_eflags(unsigned int val) */
+FUNCTION(set_eflags):
+ 	pushl	4(%esp)
+ 	popfl
+	ret

src/kernel/libroot/os/systeminfo.c

@@ -8,13 +8,61 @@
 #include "syscalls.h"
 
 
+#ifdef __INTEL__
+
+// this declaration could be placed in a header file somewhere, but it doesn't
+// appear likely that any user functions besides 'get_cpuid()' would need it...
+void cpuid(unsigned int selector, unsigned int *data);
+
+
+/*
+ *  get_cpuid() -- uses the 'cpuid' instruction to retrieve information
+ *  about the computer make & model and the capabilities of the cpu(s)
+ *	...this means the function is strictly INTEL PLATFORM ONLY!!!
+ *
+ *  parameters:
+ *            info: out - the structure to hold the cpuid information
+ *    eax_register: in  - the value to place in eax before invoking 'cpuid'
+ *         cpu_num: in  - the number of the cpu to gather information about
+ *                        (currently not used)
+ *
+ *  Note: the stage2 bootloader already verifies at startup time that the
+ *  'cpuid' instruction can be called by the host computer, so no checking
+ *  for this is done here.
+ */
+
 status_t
 get_cpuid(cpuid_info *info, uint32 eax_register, uint32 cpu_num)
 {
-	// ToDo: get_cpuid()
-	return B_ERROR;
+	unsigned int data[4];
+	
+	// call the instruction
+	cpuid(eax_register, data);
+	
+	// fill the info struct with the return values
+	info->regs.eax = data[0];
+	info->regs.ebx = data[1];
+	info->regs.ecx = data[2];
+	info->regs.edx = data[3];
+	
+	if (eax_register == 0) {
+		// fixups for this special case
+		char *vendor = info->eax_0.vendorid;
+		
+		// the high-order word is non-zero on some Cyrix CPUs
+		info->eax_0.max_eax = data[0] & 0xffff;
+		
+		// the vendor string bytes need a little re-ordering
+		*((unsigned int *) &vendor[0]) = data[1];
+		*((unsigned int *) &vendor[4]) = data[3];
+		*((unsigned int *) &vendor[8]) = data[2];
+	}
+	
+	return B_OK;
 }
 
+#endif
+
 
 status_t
 _get_system_info(system_info *returned_info, size_t size)