Espresso 0.0.2a

arch/x86/cpuid_asm.asm

@@ -0,0 +1,46 @@
+.global get_cpu_brand_string
+
+.type get_cpu_brand_string, @function
+
+get_cpu_brand_string:
+    pushad                      # Save all general-purpose registers
+
+    mov ebx, eax                # Save buffer pointer to ebx
+
+    mov eax, 0x80000000
+    cpuid
+    cmp eax, 0x80000004         # Check if brand string is supported
+    jb .not_supported
+
+    mov esi, ebx                # Copy address to ESI
+
+    mov eax, 0x80000002
+    cpuid
+    mov [esi], eax
+    mov [esi + 4], ebx
+    mov [esi + 8], ecx
+    mov [esi + 12], edx
+
+    mov eax, 0x80000003
+    cpuid
+    mov [esi + 16], eax
+    mov [esi + 20], ebx
+    mov [esi + 24], ecx
+    mov [esi + 28], edx
+
+    mov eax, 0x80000004
+    cpuid
+    mov [esi + 32], eax
+    mov [esi + 36], ebx
+    mov [esi + 40], ecx
+    mov [esi + 44], edx
+
+    jmp .done
+
+.not_supported:
+    mov byte [ebx], 0           # Null-terminate if not supported
+
+.done:
+    popad
+    ret
+