Changes in kernel/arch/amd64/src/amd64.c [af9dd1e:811770c] in mainline

File:

• kernel/arch/amd64/src/amd64.c (modified) (3 diffs)

kernel/arch/amd64/src/amd64.c

@@ -64 +64 @@
 #endif
 
-/** Disable I/O on non-privileged levels
- *
- * Clean IOPL(12,13) and NT(14) flags in EFLAGS register
- */
-static void clean_IOPL_NT_flags(void)
-{
-        asm volatile (
-                "pushfq\n"
-                "pop %%rax\n"
-                "and $~(0x7000), %%rax\n"
-                "pushq %%rax\n"
-                "popfq\n"
-                ::: "%rax"
-        );
-}
-
-/** Disable alignment check
- *
- * Clean AM(18) flag in CR0 register 
- */
-static void clean_AM_flag(void)
-{
-        asm volatile (
-                "mov %%cr0, %%rax\n"
-                "and $~(0x40000), %%rax\n"
-                "mov %%rax, %%cr0\n"
-                ::: "%rax"
-        );
-}
-
 /** Perform amd64-specific initialization before main_bsp() is called.
  *
@@ -116 +86 @@
 {
         /* Enable no-execute pages */
-        set_efer_flag(AMD_NXE_FLAG);
+        write_msr(AMD_MSR_EFER, read_msr(AMD_MSR_EFER) | AMD_NXE);
         /* Enable FPU */
         cpu_setup_fpu();
@@ -123 +93 @@
         pm_init();
         
-        /* Disable I/O on nonprivileged levels
-         * clear the NT (nested-thread) flag 
-         */
-        clean_IOPL_NT_flags();
+        /* Disable I/O on nonprivileged levels, clear the nested-thread flag */
+        write_rflags(read_rflags() & ~(RFLAGS_IOPL | RFLAGS_NT));
         /* Disable alignment check */
-        clean_AM_flag();
+        write_cr0(read_cr0() & ~CR0_AM);
         
         if (config.cpu_active == 1) {