[cpu] Split cpuid validation into separate lib

In order to allow the bootloader to do preliminary CPUID validation
while UEFI is still handling displaying information to the user, split
most of the kernel's CPUID handling into a library to be used by both
kernel and boot.

src/boot/main.cpp

@@ -8,6 +8,7 @@
 #include <stdint.h>
 
 #include "console.h"
+#include "cpu/cpu.h"
 #include "error.h"
 #include "fs.h"
 #include "hardware.h"
@@ -94,6 +95,28 @@ add_module(args::header *args, args::mod_type type, buffer &data)
 	m.size = data.size;
 }
 
+/// Check that all required cpu features are supported
+void
+check_cpu_supported()
+{
+	status_line status {L"Checking CPU features"};
+
+	cpu::cpu_id cpu;
+	uint64_t missing = cpu.missing();
+	if (missing) {
+#define CPU_FEATURE_OPT(...)
+#define CPU_FEATURE_REQ(name, ...) \
+		if (!cpu.has_feature(cpu::feature::name)) { \
+			status::fail(L"CPU required feature " L ## #name, uefi::status::unsupported); \
+		}
+#include "cpu/features.inc"
+#undef CPU_FEATURE_REQ
+#undef CPU_FEATURE_OPT
+
+		error::raise(uefi::status::unsupported, L"CPU not supported");
+	}
+}
+
 /// The main procedure for the portion of the loader that runs while
 /// UEFI is still in control of the machine. (ie, while the loader still
 /// has access to boot services.
@@ -160,6 +183,7 @@ efi_main(uefi::handle image, uefi::system_table *st)
 {
 	using namespace boot;
 	console con(st->boot_services, st->con_out);
+	check_cpu_supported();
 
 	args::header *args = uefi_preboot(image, st);
 	memory::efi_mem_map map = uefi_exit(args, image, st->boot_services);