[U-Boot] [PATCH v2 4/8] x86: quark: Lock HMBOUND register before jumping to kernel

[Bin Meng]

When Linux kernel boots, it hangs at:

[    0.829408] Intel Quark side-band driver registered

This happens when Quark kernel Isolated Memory Region (IMR) driver
tries to lock an IMR register to protect kernel's text and rodata
sections. However in order to have IMR function correctly, HMBOUND
register must be locked otherwise the system just hangs.

Signed-off-by: Bin Meng <bmeng.cn at gmail.com>
Acked-by: Simon Glass <sjg at chromium.org>
---

Changes in v2: None

 arch/x86/cpu/quark/quark.c              | 3 +++
 arch/x86/include/asm/arch-quark/quark.h | 1 +
 2 files changed, 4 insertions(+)

diff --git a/arch/x86/cpu/quark/quark.c b/arch/x86/cpu/quark/quark.c
index 8d53fe3..3ddf079 100644
--- a/arch/x86/cpu/quark/quark.c
+++ b/arch/x86/cpu/quark/quark.c
@@ -288,5 +288,8 @@ void board_final_cleanup(void)
 	val &= ~0xff0000;
 	writel(val, &rcba->esd);
 
+	/* Lock HMBOUND for security */
+	msg_port_setbits(MSG_PORT_HOST_BRIDGE, HM_BOUND, HM_BOUND_LOCK);
+
 	return;
 }
diff --git a/arch/x86/include/asm/arch-quark/quark.h b/arch/x86/include/asm/arch-quark/quark.h
index eb3afbf..338c896 100644
--- a/arch/x86/include/asm/arch-quark/quark.h
+++ b/arch/x86/include/asm/arch-quark/quark.h
@@ -32,6 +32,7 @@
 
 /* Host Memory I/O Boundary */
 #define HM_BOUND		0x08
+#define HM_BOUND_LOCK		0x00000001
 
 /* Extended Configuration Space */
 #define HEC_REG			0x09
-- 
1.8.2.1