ridesx: improve error for ridesx flashing

Signed-off-by: Benny Zlotnik <[email protected]>

Author: bennyz

packages/jumpstarter-driver-ridesx/README.md

@@ -104,7 +104,7 @@ Both drivers require:
 
 ```{testcode}
 # Flash a single partition
-ridesx_client.flash("/path/to/boot.img", partition="boot")
+ridesx_client.flash("/path/to/boot.img", target="boot")
 ```
 
 ### Flash Multiple Partitions
@@ -125,7 +125,7 @@ The driver automatically handles compressed images (`.gz`, `.gzip`, `.xz`):
 
 ```{testcode}
 # Flash compressed images - decompression is automatic
-ridesx_client.flash("/path/to/boot.img.gz", partition="boot")
+ridesx_client.flash("/path/to/boot.img.gz", target="boot")
 ```
 
 ### Power Control

packages/jumpstarter-driver-ridesx/jumpstarter_driver_ridesx/client.py

@@ -81,18 +81,22 @@ def flash(
         self,
         path: str | Dict[str, str],
         *,
-        partition: str | None = None,
+        target: str | None = None,
         operator: Operator | Dict[str, Operator] | None = None,
         compression=None,
     ):
         if isinstance(path, dict):
             partitions = path
             operators = operator if isinstance(operator, dict) else None
         else:
-            if partition is None:
-                raise ValueError("'partition' must be provided")
-            partitions = {partition: path}
-            operators = {partition: operator} if isinstance(operator, Operator) else None
+            if target is None:
+                raise ValueError(
+                    "This driver requires a target partition.\n"
+                    "Usage: j storage flash --target <partition>:<file>\n"
+                    "Example: j storage flash -t boot_a:aboot.img -t system_a:rootfs.simg -t system_b:qm_var.simg"
+                )
+            partitions = {target: path}
+            operators = {target: operator} if isinstance(operator, Operator) else None
 
         for partition_name, file_path in partitions.items():
             if not file_path or not file_path.strip():