vboot: Handle GBB_FLAG_DISABLE_LID_SHUTDOWN

Handle GBB_FLAG_DISABLE_LID_SHUTDOWN to disable lid-triggered system
shutdown.

BUG=chromium:434462
BRANCH=Auron
TEST=Manual on Auron, with corresponding depthcharge change. Set GBB
flag 0x1000 and disable powerd launch on boot. Close lid and issue
'reboot' command over ssh. Verify system reboots successfully into OS.

Change-Id: Id2731508296a5ba9229f969f8224565d64f3d4a3
Signed-off-by: Shawn Nematbakhsh <shawnn@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/234995
Reviewed-by: Randall Spangler <rspangler@chromium.org>
(cherry picked from commit 5d652cdffa70dc772e80548a760e1f0d67de273f)
Reviewed-on: https://chromium-review.googlesource.com/234993
diff --git a/firmware/include/vboot_api.h b/firmware/include/vboot_api.h
index 9b05371..7cdaaaa 100644
--- a/firmware/include/vboot_api.h
+++ b/firmware/include/vboot_api.h
@@ -850,9 +850,9 @@
 /**
  * Check if the firmware needs to shut down the system.
  *
- * Returns 1 if a shutdown is being requested (for example, the user has
- * pressed the power button or closed the lid), or 0 if a shutdown is not being
- * requested.
+ * Returns a non-zero VB_SHUTDOWN_REQUEST mask indicating the reason(s) for
+ * shutdown if a shutdown is being requested (see VB_SHUTDOWN_REQUEST_*), or 0
+ * if a shutdown is not being requested.
  *
  * NOTE: When we're displaying a screen, pressing the power button should shut
  * down the computer.  We need a way to break out of our control loop so this
@@ -860,6 +860,17 @@
  */
 uint32_t VbExIsShutdownRequested(void);
 
+/*
+ * Shutdown requested for a reason which is not defined among other
+ * VB_SHUTDOWN_REQUEST_* values. This must be defined as 1 for backward
+ * compatibility with old versions of the API.
+ */
+#define VB_SHUTDOWN_REQUEST_OTHER		0x00000001
+/* Shutdown requested due to a lid switch being closed. */
+#define VB_SHUTDOWN_REQUEST_LID_CLOSED		0x00000002
+/* Shutdown requested due to a power button being pressed. */
+#define VB_SHUTDOWN_REQUEST_POWER_BUTTON	0x00000004
+
 /**
  * Expose the BIOS' built-in decompression routine to the vboot wrapper. The
  * caller must know how large the uncompressed data will be and must manage
diff --git a/firmware/lib/vboot_api_kernel.c b/firmware/lib/vboot_api_kernel.c
index 0b2f941..b109c47 100644
--- a/firmware/lib/vboot_api_kernel.c
+++ b/firmware/lib/vboot_api_kernel.c
@@ -42,6 +42,23 @@
 }
 
 /**
+ * Checks GBB flags against VbExIsShutdownRequested() shutdown request to
+ * determine if a shutdown is required.
+ *
+ * Returns true if a shutdown is required and false if no shutdown is required.
+ */
+static int VbWantShutdown(uint32_t gbb_flags)
+{
+	uint32_t shutdown_request = VbExIsShutdownRequested();
+
+	/* If desired, ignore shutdown request due to lid closure. */
+	if (gbb_flags & GBB_FLAG_DISABLE_LID_SHUTDOWN)
+		shutdown_request &= ~VB_SHUTDOWN_REQUEST_LID_CLOSED;
+
+	return !!shutdown_request;
+}
+
+/**
  * Attempt loading a kernel from the specified type(s) of disks.
  *
  * If successful, sets p->disk_handle to the disk for the kernel and returns
@@ -143,7 +160,7 @@
 
 	/* Await further instructions */
 	while (1) {
-		if (VbExIsShutdownRequested())
+		if (VbWantShutdown(cparams->gbb->flags))
 			return -1;
 		key = VbExKeyboardReadWithFlags(&key_flags);
                 button = VbExGetSwitches(VB_INIT_FLAG_REC_BUTTON_PRESSED);
@@ -233,7 +250,7 @@
 	do {
 		uint32_t key;
 
-		if (VbExIsShutdownRequested()) {
+		if (VbWantShutdown(gbb->flags)) {
 			VBDEBUG(("VbBootDeveloper() - shutdown requested!\n"));
 			VbAudioClose(audio);
 			return VBERROR_SHUTDOWN_REQUESTED;
@@ -487,7 +504,7 @@
 			for (i = 0; i < REC_DISK_DELAY; i += REC_KEY_DELAY) {
 				VbCheckDisplayKey(cparams, VbExKeyboardRead(),
 						  &vnc);
-				if (VbExIsShutdownRequested())
+				if (VbWantShutdown(cparams->gbb->flags))
 					return VBERROR_SHUTDOWN_REQUESTED;
 				VbExSleepMs(REC_KEY_DELAY);
 			}
@@ -584,7 +601,7 @@
 			} else {
 				VbCheckDisplayKey(cparams, key, &vnc);
 			}
-			if (VbExIsShutdownRequested())
+			if (VbWantShutdown(cparams->gbb->flags))
 				return VBERROR_SHUTDOWN_REQUESTED;
 			VbExSleepMs(REC_KEY_DELAY);
 		}