Revert "2lib/2api: Deprecate vb2ex_ec_trusted()"

This reverts commit 7c73bb07fd3ca45ce650b993a9c6a5850ddb2707.

Reason for revert: b:202258389

Original change's description:
> 2lib/2api: Deprecate vb2ex_ec_trusted()
>
> coreboot will support check the EC_IN_RW during verstage_main(), which
> performs the equivalent tasks as vb2ex_ec_trusted().
>
> In the previous CL, we remove the check of vb2ex_ec_trusted(), so the
> whole implementation of this function among vboot_reference and
> depthcharge could be deprecated and removed.
>
> BUG=b:181931817
> BRANCH=none
> TEST=CC=x86_64-pc-linux-gnu-clang;
>      make clean && make runtests
> TEST=emerge coreboot vboot_reference depthcharge
>
> Cq-Depend: chromium:3139956
> Signed-off-by: Hsuan Ting Chen <roccochen@chromium.org>
> Change-Id: I4f592d7dec2480475762e1336791cbb34fa143ba
> Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/vboot_reference/+/3139539
> Reviewed-by: Julius Werner <jwerner@chromium.org>
> Reviewed-by: Yu-Ping Wu <yupingso@chromium.org>

Bug: b:181931817
Change-Id: Ia127ce89b7f9413db9fd6ca4561ad06efb36d7e1
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/vboot_reference/+/3211006
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Commit-Queue: Bhanu Prakash Maiya <bhanumaiya@google.com>

4 files changed, 23 insertions, 4 deletions

diff --git a/firmware/2lib/2ec_sync.c b/firmware/2lib/2ec_sync.c
index e75313b4..20490e08 100644
--- a/firmware/2lib/2ec_sync.c
+++ b/firmware/2lib/2ec_sync.c
@@ -160,10 +160,10 @@ static vb2_error_t check_ec_active(struct vb2_context *ctx)
 	struct vb2_shared_data *sd = vb2_get_sd(ctx);
 	int in_rw = 0;
 	/*
-	 * We don't use VB2_CONTEXT_EC_TRUSTED, which checks if not EC_IN_RW.
-	 * It is controlled by cr50 but on some platforms, cr50 can't know when
-	 * a EC resets. So, we trust what EC-RW says. If it lies it's in RO,
-	 * we'll flash RW while it's in RW.
+	 * We don't use vb2ex_ec_trusted, which checks EC_IN_RW. It is
+	 * controlled by cr50 but on some platforms, cr50 can't know when a EC
+	 * resets. So, we trust what EC-RW says. If it lies it's in RO, we'll
+	 * flash RW while it's in RW.
 	 */
 	/* If we couldn't determine where the EC was, reboot to recovery. */
 	VB2_TRY(vb2ex_ec_running_rw(&in_rw),
diff --git a/firmware/2lib/2stub.c b/firmware/2lib/2stub.c
index 85534dd6..956b4bb4 100644
--- a/firmware/2lib/2stub.c
+++ b/firmware/2lib/2stub.c
@@ -75,6 +75,12 @@ vb2_error_t vb2ex_tpm_set_mode(enum vb2_tpm_mode mode_val)
 /* auxfw and EC-related stubs */
 
 __attribute__((weak))
+int vb2ex_ec_trusted(void)
+{
+	return 1;
+}
+
+__attribute__((weak))
 vb2_error_t vb2ex_ec_running_rw(int *in_rw)
 {
 	*in_rw = 0;
diff --git a/firmware/2lib/include/2api.h b/firmware/2lib/include/2api.h
index 8cc9a923..1f9d70f9 100644
--- a/firmware/2lib/include/2api.h
+++ b/firmware/2lib/include/2api.h
@@ -1303,6 +1303,14 @@ enum vb2_firmware_selection {
 vb2_error_t vb2api_ec_sync(struct vb2_context *ctx);
 
 /**
+ * This is called only if the system implements a keyboard-based (virtual)
+ * developer switch. It must return true only if the system has an embedded
+ * controller which is provably running in its RO firmware at the time the
+ * function is called.
+ */
+int vb2ex_ec_trusted(void);
+
+/**
  * Check if the EC is currently running rewritable code.
  *
  * If the EC is in RO code, sets *in_rw=0.
diff --git a/tests/vb2_ec_sync_tests.c b/tests/vb2_ec_sync_tests.c
index e47f59d6..16496e44 100644
--- a/tests/vb2_ec_sync_tests.c
+++ b/tests/vb2_ec_sync_tests.c
@@ -121,6 +121,11 @@ uint32_t VbExIsShutdownRequested(void)
 	return 0;
 }
 
+int vb2ex_ec_trusted(void)
+{
+	return !ec_run_image;
+}
+
 vb2_error_t vb2ex_ec_running_rw(int *in_rw)
 {
 	*in_rw = ec_run_image;