setup: add option to enable FPU via cmdline

This is needed by libpfm.

Signed-off-by: Pawel Wieczorkiewicz <[email protected]>

Author: wipawel

common/setup.c

@@ -74,6 +74,9 @@ bool_cmd("apic_timer", opt_apic_timer);
 bool opt_hpet = false;
 bool_cmd("hpet", opt_hpet);
 
+bool opt_fpu = false;
+bool_cmd("fpu", opt_fpu);
+
 io_port_t __data_rmode com_ports[2] = {COM1_PORT, COM2_PORT};
 
 boot_flags_t boot_flags;
@@ -303,6 +306,11 @@ void __noreturn __text_init kernel_start(uint32_t multiboot_magic,
     if (opt_keyboard)
         init_keyboard(get_bsp_cpu_id());
 
+    if (opt_fpu) {
+        printk("Enabling FPU instructions support\n");
+        enable_fpu();
+    }
+
 #ifdef KTF_PMU
     printk("Initializing PFM library\n");
 

include/lib.h

@@ -421,7 +421,7 @@ static inline unsigned long ipow(int base, unsigned int exp) {
     return result;
 }
 
-static inline void enable_sse(void) {
+static inline void enable_fpu(void) {
     write_cr0((read_cr0() & ~X86_CR0_EM) | X86_CR0_MP);
     write_cr4(read_cr4() | X86_CR4_OSFXSR | X86_CR4_OSXMMEXCPT);
 }