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@gmail.com ---
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