feat: simple device abstraction layer

[lunaix-os.git] / lunaix-os / hal / cpu.c

diff --git a/lunaix-os/hal/cpu.c b/lunaix-os/hal/cpu.c
index ad1b0a5937e3edc1df80cfb1df96332cbac8bc4d..ab5432c9642402556c0282eb8f0ee5982d22d9fb 100644 (file)
--- a/lunaix-os/hal/cpu.c
+++ b/lunaix-os/hal/cpu.c
@@ -38,4 +38,30 @@ void cpu_get_brand(char* brand_out) {
         j+=4;
     }
     brand_out[48] = '\0';
+}
+
+
+int
+cpu_has_apic() {
+    // reference: Intel manual, section 10.4.2
+    reg32 eax = 0, ebx = 0, edx = 0, ecx = 0;
+    __get_cpuid(1, &eax, &ebx, &ecx, &edx);
+    
+    return (edx & 0x100);
+}
+
+void
+cpu_rdmsr(uint32_t msr_idx, uint32_t* reg_high, uint32_t* reg_low)
+{
+    uint32_t h = 0, l = 0;
+    asm volatile("rdmsr" : "=d"(h), "=a"(l) : "c"(msr_idx));
+
+    *reg_high = h;
+    *reg_low = l;
+}
+
+void
+cpu_wrmsr(uint32_t msr_idx, uint32_t reg_high, uint32_t reg_low)
+{
+    asm volatile("wrmsr" : : "d"(reg_high), "a"(reg_low), "c"(msr_idx));
 }
\ No newline at end of file