cros: Inform U-Boot via fake gpio when VGA Option ROM is loaded

This prepares the way for vboot to inform coreboot when it needs the VGA
Option ROM loaded. Coreboot can't always know when it's needed (with
keyboard-based dev-mode, coreboot can't tell if we're in dev-mode or not).
By the time we get to U-Boot, it's too late, so we need two extra bits - one
for vboot to tell coreboot to load the Option ROM and another for coreboot
to let vboot know it's been done.

This change sets up the communication, but doesn't act on it just yet.

Even with this CL we always load the VGA Option ROM, so there's nothing to
test. There should be no user-visible change.

Change-Id: Ic4e9673a3707b6605064f4879bb3e74d4412322f
Signed-off-by: Bill Richardson <wfrichar@chromium.org>
Reviewed-on: http://review.coreboot.org/1822
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>

3 files changed, 31 insertions, 6 deletions

diff --git a/src/devices/pci_device.c b/src/devices/pci_device.c
index 7fa738448d..94f68ea1ab 100644
--- a/src/devices/pci_device.c
+++ b/src/devices/pci_device.c
@@ -656,6 +656,10 @@ void pci_dev_set_subsystem(struct device *dev, unsigned vendor, unsigned device)
 			   ((device & 0xffff) << 16) | (vendor & 0xffff));
 }
 
+#if CONFIG_CHROMEOS
+int oprom_is_loaded = 0;
+#endif
+
 /** Default handler: only runs the relevant PCI BIOS. */
 void pci_dev_init(struct device *dev)
 {
@@ -675,8 +679,11 @@ void pci_dev_init(struct device *dev)
 	 * we don't run (VGA) option ROMs, unless we have to print
 	 * something on the screen before the kernel is loaded.
 	 */
-	if (!developer_mode_enabled() && !recovery_mode_enabled())
+	if (!developer_mode_enabled() && !recovery_mode_enabled() &&
+	    !vboot_wants_oprom()) {
+		printk(BIOS_DEBUG, "Not loading VGA Option ROM\n");
 		return;
+	}
 #endif
 
 	rom = pci_rom_probe(dev);
@@ -696,6 +703,10 @@ void pci_dev_init(struct device *dev)
 		return;
 #endif
 	run_bios(dev, (unsigned long)ram);
+#if CONFIG_CHROMEOS
+	oprom_is_loaded = 1;
+	printk(BIOS_DEBUG, "VGA Option ROM has been loaded\n");
+#endif
 #endif /* CONFIG_PCI_ROM_RUN || CONFIG_VGA_ROM_RUN */
 }
 
diff --git a/src/vendorcode/google/chromeos/chromeos.h b/src/vendorcode/google/chromeos/chromeos.h
index ec0f3b733a..37630a69bc 100644
--- a/src/vendorcode/google/chromeos/chromeos.h
+++ b/src/vendorcode/google/chromeos/chromeos.h
@@ -29,6 +29,8 @@ void save_chromeos_gpios(void);
 
 /* functions implemented in vbnv.c: */
 int get_recovery_mode_from_vbnv(void);
+int vboot_wants_oprom(void);
+extern int oprom_is_loaded;
 
 /* functions implemented in chromeos.c: */
 int developer_mode_enabled(void);
diff --git a/src/vendorcode/google/chromeos/vbnv.c b/src/vendorcode/google/chromeos/vbnv.c
index 2129461fc1..3f333f7211 100644
--- a/src/vendorcode/google/chromeos/vbnv.c
+++ b/src/vendorcode/google/chromeos/vbnv.c
@@ -38,6 +38,8 @@
 
 #define BOOT_OFFSET                  1
 #define BOOT_DEBUG_RESET_MODE           0x80
+#define BOOT_DISABLE_DEV_REQUEST        0x40
+#define BOOT_OPROM_NEEDED               0x20
 #define BOOT_TRY_B_COUNT_MASK           0x0F
 
 #define RECOVERY_OFFSET              2
@@ -45,11 +47,7 @@
 
 #define DEV_FLAGS_OFFSET             4
 #define DEV_BOOT_USB_MASK               0x01
-
-#define FIRMWARE_FLAGS_OFFSET        5
-#define FIRMWARE_TEST_ERR_FUNC_MASK     0x38
-#define FIRMWARE_TEST_ERR_FUNC_SHIFT    3
-#define FIRMWARE_TEST_ERR_NUM_MASK      0x07
+#define DEV_BOOT_SIGNED_ONLY_MASK       0x02
 
 #define KERNEL_FIELD_OFFSET         11
 #define CRC_OFFSET                  15
@@ -107,3 +105,17 @@ int get_recovery_mode_from_vbnv(void)
 		vbnv_setup();
 	return vbnv[RECOVERY_OFFSET];
 }
+
+int vboot_wants_oprom(void)
+{
+	if (!vbnv_initialized)
+		vbnv_setup();
+
+	/* FIXME(crosbug.com/p/8789). The following commented-out line does the
+	 * right thing, assuming that vboot has requested the option ROM and
+	 * rebooted if it finds that it's needed but not loaded. At the moment,
+	 * it doesn't yet do that, so we must always say we want it. */
+
+	/* return (vbnv[BOOT_OFFSET] & BOOT_OPROM_NEEDED) ? 1 : 0; */
+	return 1;
+}