Fix the ordering of UEFI vs legacy probing

The first and most important change is to ensure that we never try to
grab the host ESP when we're operating in image mode. This alone causes
issues when producing images using "--path", i.e. VHD imagery.

Secondly, we ensure that we *always* set image mode *before* we set the
prefix, as this prefix is only ever set once. This is the part where we
inspect the root of the system we're looking at, and determine whether
we're dealing with legacy or UEFI, or legacy+gpt (i.e. Azure images).

Lastly, we make sure that update_image follows the lead of update_native
by re-initialising the bootloader prior to using it, with the current
root + boot directory settings, ensuring we're always using fresh
values and world view.

Signed-off-by: Ikey Doherty <michael.i.doherty@intel.com>

src/bootman/sysconfig.c

@@ -77,9 +77,10 @@ SystemConfig *cbm_inspect_root(const char *path, bool image_mode)
          * UEFI. This is due to GPT being able to contain a legacy boot device
          * *and* an ESP at the same time. Native UEFI takes precedence.
          */
-        if (!native_uefi) {
+        if (!native_uefi || image_mode) {
                 boot = get_legacy_boot_device(realp);
         }
+
         if (boot) {
                 c->boot_device = boot;
                 c->wanted_boot_mask = BOOTLOADER_CAP_LEGACY | BOOTLOADER_CAP_GPT;
@@ -88,7 +89,9 @@ SystemConfig *cbm_inspect_root(const char *path, bool image_mode)
         }
 
         /* Now try to find the system ESP */
-        boot = get_boot_device();
+        if (!image_mode) {
+                boot = get_boot_device();
+        }
         if (boot) {
                 c->boot_device = boot;
                 c->wanted_boot_mask = BOOTLOADER_CAP_UEFI | BOOTLOADER_CAP_GPT;

src/bootman/update.c

@@ -184,6 +184,14 @@ static bool boot_manager_update_image(BootManager *self)
                 return false;
         }
 
+        /* Reinit bootloader for image mode to ensure the bootloader is then
+         * re-initialised for the current settings and environment.
+         */
+        if (!boot_manager_set_boot_dir(self, boot_dir)) {
+                LOG_FATAL("Cannot re-initialise bootloader for image mode");
+                return false;
+        }
+
         /* Sort them to find the newest kernel */
         nc_array_qsort(kernels, kernel_compare_reverse);
 

src/cli/ops/update.c

@@ -24,7 +24,6 @@ bool cbm_command_update(int argc, char **argv)
 {
         autofree(char) *root = NULL;
         autofree(BootManager) *manager = NULL;
-        bool image_mode = false;
         bool forced_image = false;
 
         if (!cli_default_args_init(&argc, &argv, &root, &forced_image)) {
@@ -47,7 +46,9 @@ bool cbm_command_update(int argc, char **argv)
                 }
                 /* Anything not / is image mode */
                 if (!streq(realp, "/")) {
-                        image_mode = true;
+                        boot_manager_set_image_mode(manager, true);
+                } else {
+                        boot_manager_set_image_mode(manager, forced_image);
                 }
 
                 /* CBM will check this again, we just needed to check for
@@ -56,19 +57,13 @@ bool cbm_command_update(int argc, char **argv)
                         return false;
                 }
         } else {
+                boot_manager_set_image_mode(manager, forced_image);
                 /* Default to "/", bail if it doesn't work. */
                 if (!boot_manager_set_prefix(manager, "/")) {
                         return false;
                 }
         }
 
-        if (forced_image) {
-                boot_manager_set_image_mode(manager, true);
-        } else {
-                /* Set the image mode */
-                boot_manager_set_image_mode(manager, image_mode);
-        }
-
         /* Let CBM take care of the rest */
         return boot_manager_update(manager);
 }