Driver-originated vulnerabilities are well-known threats to modern monolithic kernels. However, existing driver isolation solutions either rely on Intel-only or newly-introduced CPU features (e.g., Intel VMFUNC, ARM MTE), or suffer from performance issues, making them unsuitable for existing ARM-based devices. In this work, we leverage a common hardware feature, named hardware watchpoint, to achieve lightweight driver isolation for off-the-shelf ARM devices. Specifically, we utilize watchpoints to prevent the possibly compromised driver from corrupting the rest kernel’s state arbitrarily. We implement a prototype for ARM64 Linux. The security analysis and performance evaluation show the efficiency and practicality of our solution.