| 26,68 → 26,25 |
|---|
| # THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| # |
| |
| # The code below just interfaces the CPUID instruction. |
| # CPU recognition logic is contained in higher-level functions. |
| |
| .text |
| |
| .global has_cpuid |
| .global cpuid |
| .global rdtsc |
| |
| |
| ## Determine CPUID support |
| # |
| # Return 0 in EAX if CPUID is not support, 1 if supported. |
| # Return 0 in EAX if CPUID is not supported, 1 if supported. |
| # |
| has_cpuid: |
| push %ebx |
| |
| pushf # store flags |
| popl %eax # read flags |
| movl %eax,%ebx # copy flags |
| btcl $21,%ebx # swap the ID bit |
| pushl %ebx |
| movl %eax,%edx # copy flags |
| btcl $21,%edx # swap the ID bit |
| pushl %edx |
| popf # propagate the change into flags |
| pushf |
| popl %ebx # read flags |
| popl %edx # read flags |
| andl $(1<<21),%eax # interested only in ID bit |
| andl $(1<<21),%ebx |
| xorl %ebx,%eax # 0 if not supported, 1 if supported |
| |
| pop %ebx |
| andl $(1<<21),%edx |
| xorl %edx,%eax # 0 if not supported, 1 if supported |
| ret |
| |
| |
| ## Get CPUID data |
| # |
| # This code is just an interfaces the CPUID instruction, CPU recognition |
| # logic is contained in higher-level functions. |
| # |
| # The C prototype is: |
| # void cpuid(__u32 cmd, struct cpu_info *info) |
| # |
| # @param cmd CPUID command. |
| # @param info Buffer to store CPUID output. |
| # |
| cpuid: |
| pushl %ebp |
| movl %esp,%ebp |
| pusha |
| |
| movl 8(%ebp),%eax # load the command into %eax |
| movl 12(%ebp),%esi # laod the address of the info struct |
| |
| cpuid |
| movl %eax,0(%esi) |
| movl %ebx,4(%esi) |
| movl %ecx,8(%esi) |
| movl %edx,12(%esi) |
| |
| popa |
| popl %ebp |
| ret |
| |
| rdtsc: |
| rdtsc |
| ret |