chroot/other/kernel_flavor_installed: support generic kernel name (MR 2093)

kernel is named /boot/vmlinuz now, looking at the filename will no
longer tell us what flavor it is. This now will look at
/usr/share/kernel, which has always contained the kernel 'flavor', and
since we currently only install 1 kernel these days, guarding this with
pmaports.cfg should be unnecessary. In the worst case (if there are
multiple kernel 'flavors' installed), it'll just grab the first one and
return it.

pmb/chroot/initfs.py

@@ -80,8 +80,7 @@ def ls(args, flavor, suffix, extra=False):
 def frontend(args):
     # Find the appropriate kernel flavor
     suffix = f"rootfs_{args.device}"
-    flavors = pmb.chroot.other.kernel_flavors_installed(args, suffix)
-    flavor = flavors[0]
+    flavor = pmb.chroot.other.kernel_flavor_installed(args, suffix)
 
     # Handle initfs actions
     action = args.action_initfs
@@ -107,9 +106,8 @@ def frontend(args):
         elif action == "hook_del":
             pmb.chroot.initfs_hooks.delete(args, args.hook, suffix)
 
-        # Rebuild the initfs for all kernels after adding/removing a hook
-        for flavor in flavors:
-            build(args, flavor, suffix)
+        # Rebuild the initfs after adding/removing a hook
+        build(args, flavor, suffix)
 
     if action in ["ls", "extract"]:
         link = "https://wiki.postmarketos.org/wiki/Initramfs_development"

pmb/chroot/other.py

@@ -7,33 +7,28 @@ import pmb.chroot.apk
 import pmb.install
 
 
-def kernel_flavors_installed(args, suffix, autoinstall=True):
+def kernel_flavor_installed(args, suffix, autoinstall=True):
     """
-    Get all installed kernel flavors and make sure that there's at least one
+    Get installed kernel flavor. Optionally install the device's kernel
+    beforehand.
 
     :param suffix: the chroot suffix, e.g. "native" or "rootfs_qemu-amd64"
-    :param autoinstall: make sure that at least one kernel flavor is installed
-    :returns: list of installed kernel flavors, e.g. ["postmarketos-mainline"]
+    :param autoinstall: install the device's kernel if it is not installed
+    :returns: * string with the installed kernel flavor,
+                e.g. ["postmarketos-qcom-sdm845"]
+              * None if no kernel is installed
     """
     # Automatically install the selected kernel
     if autoinstall:
-        packages = (["device-" + args.device] +
+        packages = ([f"device-{args.device}"] +
                     pmb.install.get_kernel_package(args, args.device))
         pmb.chroot.apk.install(args, packages, suffix)
 
-    # Find all kernels in /boot
-    prefix = "vmlinuz-"
-    prefix_len = len(prefix)
-    pattern = args.work + "/chroot_" + suffix + "/boot/" + prefix + "*"
-    ret = []
-    for file in glob.glob(pattern):
-        flavor = os.path.basename(file)[prefix_len:]
-        if flavor[-4:] == "-dtb" or flavor[-4:] == "-mtk":
-            flavor = flavor[:-4]
-        ret.append(flavor)
+    pattern = f"{args.work}/chroot_{suffix}/usr/share/kernel/*"
+    glob_result = glob.glob(pattern)
 
-    # Return without duplicates
-    return list(set(ret))
+    # There should be only one directory here
+    return os.path.basename(glob_result[0]) if glob_result else None
 
 
 def tempfolder(args, path, suffix="native"):

pmb/flasher/frontend.py

@@ -42,8 +42,7 @@ def kernel(args):
 def list_flavors(args):
     suffix = "rootfs_" + args.device
     logging.info("(" + suffix + ") installed kernel flavors:")
-    for flavor in pmb.chroot.other.kernel_flavors_installed(args, suffix):
-        logging.info("* " + flavor)
+    logging.info("* " + pmb.chroot.other.kernel_flavor_installed(args, suffix))
 
 
 def rootfs(args):

pmb/helpers/frontend.py

@@ -38,17 +38,19 @@ def _parse_flavor(args, autoinstall=True):
     Verify the flavor argument if specified, or return a default value.
     :param autoinstall: make sure that at least one kernel flavor is installed
     """
-    # Install at least one kernel and get installed flavors
+    # Install a kernel and get its "flavor", where flavor is a pmOS-specific
+    # identifier that is typically in the form
+    # "postmarketos-<manufacturer>-<device/chip>", e.g.
+    # "postmarketos-qcom-sdm845"
     suffix = "rootfs_" + args.device
-    flavors = pmb.chroot.other.kernel_flavors_installed(
+    flavor = pmb.chroot.other.kernel_flavor_installed(
         args, suffix, autoinstall)
 
-    # Parse and verify flavor
-    if not len(flavors):
+    if not flavor:
         raise RuntimeError(
             "No kernel flavors installed in chroot " + suffix + "! Please let"
             " your device package depend on a package starting with 'linux-'.")
-    return flavors[0]
+    return flavor
 
 
 def _parse_suffix(args):

pmb/install/_install.py

@@ -846,8 +846,8 @@ def create_device_rootfs(args, step, steps):
     # because that doesn't always happen automatically yet, e.g. when the user
     # installed a hook without pmbootstrap - see #69 for more info)
     pmb.chroot.apk.install(args, install_packages, suffix)
-    for flavor in pmb.chroot.other.kernel_flavors_installed(args, suffix):
-        pmb.chroot.initfs.build(args, flavor, suffix)
+    flavor = pmb.chroot.other.kernel_flavor_installed(args, suffix)
+    pmb.chroot.initfs.build(args, flavor, suffix)
 
     # Set the user password
     setup_login(args, suffix)

pmb/qemu/run.py

@@ -96,7 +96,7 @@ def command_qemu(args, arch, img_path, img_path_2nd=None):
 
     suffix = "rootfs_" + args.device
     rootfs = args.work + "/chroot_" + suffix
-    flavor = pmb.chroot.other.kernel_flavors_installed(args, suffix)[0]
+    flavor = pmb.chroot.other.kernel_flavor_installed(args, suffix)
     ncpus = os.cpu_count()
 
     # QEMU mach-virt's max CPU count is 8, limit it so it will work correctly