update README and misc refine

README.md

@@ -72,6 +72,7 @@ We now support both VB 1.0 and AVB 2.0 layouts.
 | Device Model                   | Manufacturer | Compatible           | Android Version          | Note |
 |--------------------------------|--------------|----------------------|--------------------------|------|
 | Pixel XL (marlin)              | HTC          | Y                    | 9.0.0 (PPR2.180905.006, <Br>Sep 2018)| [more ...](doc/additional_tricks.md#pixel-xl-marlin) |
+| Z18(NX606J)                    | ZTE          | Y                    | 8.1.0                    | [more...](doc/additional_tricks.md#nx606j) |
 | Nexus 9 (volantis/flounder)    | HTC          | Y(with some tricks)  | 7.1.1 (N9F27M, Oct 2017) | [tricks](doc/additional_tricks.md#tricks-for-nexus-9volantis)|
 | Nexus 5x (bullhead)            | LG           | Y                    | 6.0.0_r12 (MDA89E)       |      |
 | Moto X (2013) T-Mobile         | Motorola     | N                    |                          |      |

bbootimg/src/main/kotlin/Signer.kt

@@ -54,7 +54,7 @@ class Signer {
                             "--hash_algorithm ${sig.hashAlgorithm} " +
                             "--algorithm ${sig.algorithm} "
                     if (signKey!!.defaultKey.isNotBlank()) {
-                        cmdlineStr += "--key ${signKey!!.defaultKey}"
+                        cmdlineStr += "--key ${signKey.defaultKey}"
                     }
                     log.warn(cmdlineStr)
                     val cmdLine = CommandLine.parse(cmdlineStr)

doc/additional_tricks.md

@@ -37,3 +37,8 @@ Now we can work with 'raw\_boot'
 
 Due to the configuration "BOARD_BUILD_SYSTEM_ROOT_IMAGE := true", the embeded ramdisk in boot.img is actually used in recovery mode.
 
+## NX606J
+
+Thanks to the work by [CallMESuper], ZTE NX606J boot.img is also verified to be compatible with this toolkit.
+
+ROM download page: [http://ui.nubia.cn/rom/detail/56](http://ui.nubia.cn/rom/detail/56)