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-rw-r--r--arch/x86/cpu/cpu.c64
-rw-r--r--arch/x86/include/asm/cpu.h7
-rw-r--r--include/configs/coreboot.h1
3 files changed, 72 insertions, 0 deletions
diff --git a/arch/x86/cpu/cpu.c b/arch/x86/cpu/cpu.c
index 7a4de29..8c1eacc 100644
--- a/arch/x86/cpu/cpu.c
+++ b/arch/x86/cpu/cpu.c
@@ -275,3 +275,67 @@ void cpu_disable_paging_pae(void)
:
: "eax");
}
+
+static bool has_cpuid(void)
+{
+ unsigned long flag;
+
+ asm volatile("pushf\n" \
+ "pop %%eax\n"
+ "mov %%eax, %%ecx\n" /* ecx = flags */
+ "xor %1, %%eax\n"
+ "push %%eax\n"
+ "popf\n" /* flags ^= $2 */
+ "pushf\n"
+ "pop %%eax\n" /* eax = flags */
+ "push %%ecx\n"
+ "popf\n" /* flags = ecx */
+ "xor %%ecx, %%eax\n"
+ "mov %%eax, %0"
+ : "=r" (flag)
+ : "i" (1 << 21)
+ : "eax", "ecx", "memory");
+
+ return flag != 0;
+}
+
+static bool can_detect_long_mode(void)
+{
+ unsigned long flag;
+
+ asm volatile("mov $0x80000000, %%eax\n"
+ "cpuid\n"
+ "mov %%eax, %0"
+ : "=r" (flag)
+ :
+ : "eax", "ebx", "ecx", "edx", "memory");
+
+ return flag > 0x80000000UL;
+}
+
+static bool has_long_mode(void)
+{
+ unsigned long flag;
+
+ asm volatile("mov $0x80000001, %%eax\n"
+ "cpuid\n"
+ "mov %%edx, %0"
+ : "=r" (flag)
+ :
+ : "eax", "ebx", "ecx", "edx", "memory");
+
+ return flag & (1 << 29) ? true : false;
+}
+
+int cpu_has_64bit(void)
+{
+ return has_cpuid() && can_detect_long_mode() &&
+ has_long_mode();
+}
+
+int print_cpuinfo(void)
+{
+ printf("CPU: %s\n", cpu_has_64bit() ? "x86_64" : "x86");
+
+ return 0;
+}
diff --git a/arch/x86/include/asm/cpu.h b/arch/x86/include/asm/cpu.h
index 2938087..32930bd 100644
--- a/arch/x86/include/asm/cpu.h
+++ b/arch/x86/include/asm/cpu.h
@@ -19,4 +19,11 @@ void cpu_enable_paging_pae(ulong cr3);
*/
void cpu_disable_paging_pae(void);
+/**
+ * cpu_has_64bit() - Check if the CPU has 64-bit support
+ *
+ * @return 1 if this CPU supports long mode (64-bit), 0 if not
+ */
+int cpu_has_64bit(void);
+
#endif
diff --git a/include/configs/coreboot.h b/include/configs/coreboot.h
index 4b90dc2..a65d89b 100644
--- a/include/configs/coreboot.h
+++ b/include/configs/coreboot.h
@@ -26,6 +26,7 @@
#define CONFIG_PHYSMEM
#define CONFIG_SYS_EARLY_PCI_INIT
#define CONFIG_DISPLAY_BOARDINFO_LATE
+#define CONFIG_DISPLAY_CPUINFO
#define CONFIG_DM
#define CONFIG_CMD_DM