[PATCH v3 6/7] x86: Add a way to detect running from coreboot

[Simon Glass]

If U-Boot is running from coreboot we need to skip low-level init. Add
an way to detect this and to set the gd flag.

Signed-off-by: Simon Glass <sjg at chromium.org>
---

Changes in v3:
- Add new patch to detect running from coreboot

Changes in v2: None

 arch/x86/cpu/i386/cpu.c           | 15 +++++++++++++++
 arch/x86/include/asm/u-boot-x86.h |  7 +++++++
 2 files changed, 22 insertions(+)

diff --git a/arch/x86/cpu/i386/cpu.c b/arch/x86/cpu/i386/cpu.c
index c8da7f10e9..e43444c090 100644
--- a/arch/x86/cpu/i386/cpu.c
+++ b/arch/x86/cpu/i386/cpu.c
@@ -447,10 +447,25 @@ int x86_cpu_init_f(void)
 	return 0;
 }
 
+bool x86_detect_coreboot(void)
+{
+	u32 *ptr, *end;
+
+	/* We look for LBIO in the first 4K of RAM */
+	for (ptr = NULL, end = ptr + 0x400; ptr < end; ptr += 4) {
+		if (*ptr == 0x4f49424c) /* "LBIO" */
+			return true;
+	}
+
+	return false;
+}
+
 int x86_cpu_reinit_f(void)
 {
 	setup_identity();
 	setup_pci_ram_top();
+	if (x86_detect_coreboot())
+		gd->flags |= GD_FLG_NO_LL_INIT;
 
 	return 0;
 }
diff --git a/arch/x86/include/asm/u-boot-x86.h b/arch/x86/include/asm/u-boot-x86.h
index 3e5d56d075..654880f91c 100644
--- a/arch/x86/include/asm/u-boot-x86.h
+++ b/arch/x86/include/asm/u-boot-x86.h
@@ -43,6 +43,13 @@ int x86_cpu_reinit_f(void);
  */
 int x86_cpu_init_tpl(void);
 
+/**
+ * x86_detect_coreboot() - See if U-Boot is being started from coreboot
+ *
+ * @return true if coreboot is running, false if U-Boot is running 'bare-metal'
+ */
+bool x86_detect_coreboot(void);
+
 int cpu_init_f(void);
 void setup_gdt(struct global_data *id, u64 *gdt_addr);
 /*
-- 
2.25.1.481.gfbce0eb801-goog