vboot: implement DISPLAY_INIT context and SD flag

As part of go/vboot2-cleanup-oprom, introduce new context
flag DISPLAY_INIT.  The equivalent shared data flag
DISPLAY_AVAILABLE is also introduced for downstream vboot
to read.

The context flag serves the dual purpose of:

(1) the vboot caller (coreboot) telling vboot that "display
    will be initialized regardless", for cases when a
    mainboard/SoC cannot disable its display initialization
    code (see coreboot Kconfig VBOOT_MUST_REQUEST_DISPLAY,
    previously VBOOT_OPROM_MATTERS).

(2) vboot telling the vboot caller (coreboot) that "display
    initialization should occur" for cases when vboot needs
    display enabled on this boot.

BUG=b:124141368, chromium:948529
TEST=make clean && make runtests
BRANCH=none

Change-Id: If18bedf99c0f6e366c12d043377edb7bcdb35fdf
Signed-off-by: Joel Kitching <kitching@google.com>
Reviewed-on: https://chromium-review.googlesource.com/1564232
Commit-Ready: Joel Kitching <kitching@chromium.org>
Tested-by: Joel Kitching <kitching@chromium.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>

3 files changed, 33 insertions, 0 deletions

diff --git a/firmware/2lib/2api.c b/firmware/2lib/2api.c
index 707f2027..1556c997 100644
--- a/firmware/2lib/2api.c
+++ b/firmware/2lib/2api.c
@@ -37,9 +37,11 @@ void vb2api_fail(struct vb2_context *ctx, uint8_t reason, uint8_t subcode)
 int vb2api_fw_phase1(struct vb2_context *ctx)
 {
 	int rv;
+	struct vb2_shared_data *sd;
 
 	/* Initialize the vboot context if it hasn't been yet */
 	vb2_init_context(ctx);
+	sd = vb2_get_sd(ctx);
 
 	/* Initialize NV context */
 	vb2_nv_init(ctx);
@@ -97,6 +99,21 @@ int vb2api_fw_phase1(struct vb2_context *ctx)
 		return rv;
 	}
 
+	/*
+	 * Check for possible reasons to ask the firmware to make display
+	 * available.  sd->recovery_reason may have been set above by
+	 * vb2_check_recovery.  VB2_SD_FLAG_DEV_MODE_ENABLED may have been set
+	 * above by vb2_check_dev_switch.
+	 */
+	if (!(ctx->flags & VB2_CONTEXT_DISPLAY_INIT) &&
+	    (vb2_nv_get(ctx, VB2_NV_OPROM_NEEDED) ||
+	     sd->flags & VB2_SD_FLAG_DEV_MODE_ENABLED ||
+	     sd->recovery_reason))
+		ctx->flags |= VB2_CONTEXT_DISPLAY_INIT;
+	/* Mark display as available for downstream vboot and vboot callers. */
+	if (ctx->flags & VB2_CONTEXT_DISPLAY_INIT)
+		sd->flags |= VB2_SD_FLAG_DISPLAY_AVAILABLE;
+
 	/* Return error if recovery is needed */
 	if (ctx->flags & VB2_CONTEXT_RECOVERY_MODE) {
 		/* Always clear RAM when entering recovery mode */
diff --git a/firmware/2lib/include/2api.h b/firmware/2lib/include/2api.h
index 5edbc506..68fb12bd 100644
--- a/firmware/2lib/include/2api.h
+++ b/firmware/2lib/include/2api.h
@@ -161,6 +161,19 @@ enum vb2_context_flags {
 
 	/* Allow vendor data to be set via the vendor data ui. */
 	VB2_CONTEXT_VENDOR_DATA_SETTABLE = (1 << 19),
+
+	/*
+	 * Caller may set this before running vb2api_fw_phase1.  In this case,
+	 * it means: "Display is available on this boot.  Please advertise
+	 * as such to downstream vboot code and users."
+	 *
+	 * vboot may also set this before returning from vb2api_fw_phase1.
+	 * In this case, it means: "Please initialize display so that it is
+	 * available to downstream vboot code and users."  This is used when
+	 * vboot encounters some internally-generated request for display
+	 * support.
+	 */
+	VB2_CONTEXT_DISPLAY_INIT = (1 << 20),
 };
 
 /*
diff --git a/firmware/2lib/include/2struct.h b/firmware/2lib/include/2struct.h
index a67518c8..adff0d7b 100644
--- a/firmware/2lib/include/2struct.h
+++ b/firmware/2lib/include/2struct.h
@@ -49,6 +49,9 @@ enum vb2_shared_data_flags {
 	/* Software sync says EC / PD running RW */
 	VB2_SD_FLAG_ECSYNC_EC_IN_RW = (1 << 6),
 	VB2_SD_FLAG_ECSYNC_PD_IN_RW = (1 << 7),
+
+	/* Display is available on this boot */
+	VB2_SD_FLAG_DISPLAY_AVAILABLE = (1 << 8),
 };
 
 /* Flags for vb2_shared_data.status */