vboot: Support booting from non-active miniOS partition

To support booting from the non-active miniOS partition in recovery UI,
add minios_flags argument to VbTryLoadMiniOsKernel. Currently there is
only one flag: VB_MINIOS_FLAG_NON_ACTIVE. When it is set, we will
attempt to boot from the non-active partition only.

BUG=b:200750322
TEST=make runtests
BRANCH=none

Cq-Depend: chromium:3219727
Change-Id: I6221f10c09de2487e89e6113981bc9e9755d67f4
Signed-off-by: Yu-Ping Wu <yupingso@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/vboot_reference/+/3219901
Reviewed-by: Julius Werner <jwerner@chromium.org>
Reviewed-by: Jae Hoon Kim <kimjae@chromium.org>

4 files changed, 24 insertions, 9 deletions

diff --git a/firmware/include/vboot_api.h b/firmware/include/vboot_api.h
index f19ee747..1fee766d 100644
--- a/firmware/include/vboot_api.h
+++ b/firmware/include/vboot_api.h
@@ -89,6 +89,11 @@ vb2_error_t VbSelectAndLoadKernel(struct vb2_context *ctx,
  */
 vb2_error_t VbTryLoadKernel(struct vb2_context *ctx, uint32_t disk_flags);
 
+/* miniOS flags */
+
+/* Boot from non-active miniOS partition only */
+#define VB_MINIOS_FLAG_NON_ACTIVE (1 << 0)
+
 /**
  * Attempt loading a miniOS kernel from internal disk.
  *
@@ -100,9 +105,11 @@ vb2_error_t VbTryLoadKernel(struct vb2_context *ctx, uint32_t disk_flags);
  * VB2_SUCCESS.
  *
  * @param ctx			Vboot context
+ * @param minios_flags		Flags for miniOS
  * @return VB2_SUCCESS or the most specific VB2_ERROR_LK error.
  */
-vb2_error_t VbTryLoadMiniOsKernel(struct vb2_context *ctx);
+vb2_error_t VbTryLoadMiniOsKernel(struct vb2_context *ctx,
+				  uint32_t minios_flags);
 
 /*****************************************************************************/
 /* Disk access (previously in boot_device.h) */
diff --git a/firmware/lib/include/load_kernel_fw.h b/firmware/lib/include/load_kernel_fw.h
index af454703..76d25560 100644
--- a/firmware/lib/include/load_kernel_fw.h
+++ b/firmware/lib/include/load_kernel_fw.h
@@ -30,11 +30,12 @@ vb2_error_t LoadKernel(struct vb2_context *ctx,
  * @param ctx		Vboot context
  * @param params	Params specific to loading the kernel
  * @param disk_info	Disk from which to read kernel
+ * @param minios_flags	Flags for miniOS
  *
  * Returns VB2_SUCCESS if successful.  If unsuccessful, returns an error code.
  */
 vb2_error_t LoadMiniOsKernel(struct vb2_context *ctx,
 			     VbSelectAndLoadKernelParams *params,
-			     VbDiskInfo *disk_info);
+			     VbDiskInfo *disk_info, uint32_t minios_flags);
 
 #endif  /* VBOOT_REFERENCE_LOAD_KERNEL_FW_H_ */
diff --git a/firmware/lib/vboot_api_kernel.c b/firmware/lib/vboot_api_kernel.c
index 2abd57eb..54447c26 100644
--- a/firmware/lib/vboot_api_kernel.c
+++ b/firmware/lib/vboot_api_kernel.c
@@ -62,7 +62,8 @@ static int is_valid_disk(VbDiskInfo *info, uint32_t disk_flags)
 }
 
 static vb2_error_t VbTryLoadKernelImpl(struct vb2_context *ctx,
-				       uint32_t disk_flags, int minios)
+				       uint32_t disk_flags, int minios,
+				       uint32_t minios_flags)
 {
 	vb2_error_t rv = VB2_ERROR_LK_NO_DISK_FOUND;
 	VbDiskInfo* disk_info = NULL;
@@ -96,7 +97,7 @@ static vb2_error_t VbTryLoadKernelImpl(struct vb2_context *ctx,
 
 		if (minios) {
 			new_rv = LoadMiniOsKernel(ctx, kparams_ptr,
-						  &disk_info[i]);
+						  &disk_info[i], minios_flags);
 			VB2_DEBUG("LoadMiniOsKernel() = %#x\n", new_rv);
 		} else {
 			new_rv = LoadKernel(ctx, kparams_ptr, &disk_info[i]);
@@ -142,13 +143,14 @@ static vb2_error_t VbTryLoadKernelImpl(struct vb2_context *ctx,
 test_mockable
 vb2_error_t VbTryLoadKernel(struct vb2_context *ctx, uint32_t disk_flags)
 {
-	return VbTryLoadKernelImpl(ctx, disk_flags, 0);
+	return VbTryLoadKernelImpl(ctx, disk_flags, 0, 0);
 }
 
 test_mockable
-vb2_error_t VbTryLoadMiniOsKernel(struct vb2_context *ctx)
+vb2_error_t VbTryLoadMiniOsKernel(struct vb2_context *ctx,
+				  uint32_t minios_flags)
 {
-	return VbTryLoadKernelImpl(ctx, VB_DISK_FLAG_FIXED, 1);
+	return VbTryLoadKernelImpl(ctx, VB_DISK_FLAG_FIXED, 1, minios_flags);
 }
 
 vb2_error_t VbSelectAndLoadKernel(struct vb2_context *ctx,
diff --git a/firmware/lib/vboot_kernel.c b/firmware/lib/vboot_kernel.c
index 34a8a426..cb83d40d 100644
--- a/firmware/lib/vboot_kernel.c
+++ b/firmware/lib/vboot_kernel.c
@@ -607,12 +607,17 @@ static vb2_error_t try_minios_sector_region(struct vb2_context *ctx,
  */
 vb2_error_t LoadMiniOsKernel(struct vb2_context *ctx,
 			     VbSelectAndLoadKernelParams *params,
-			     VbDiskInfo *disk_info)
+			     VbDiskInfo *disk_info, uint32_t minios_flags)
 {
 	vb2_error_t rv;
 	int end_region_first = vb2_nv_get(ctx, VB2_NV_MINIOS_PRIORITY);
 
-	rv = try_minios_sector_region(ctx, params, disk_info, end_region_first);
+	if (minios_flags & VB_MINIOS_FLAG_NON_ACTIVE)
+		rv = VB2_ERROR_UNKNOWN;  /* Ignore active partition */
+	else
+		rv = try_minios_sector_region(ctx, params, disk_info,
+					      end_region_first);
+
 	if (rv)
 		rv = try_minios_sector_region(ctx, params, disk_info,
 					      !end_region_first);