Story 6.3 — Guest execution

[Abhinkop]

Goal

Boot and run the existing EL1 kernel correctly under stage-2 translation.

Tasks

• Handle stage-2 faults in EL2 vector: print IPA + fault class, halt
• Map UART MMIO in stage-2 as device memory so EL1 kprintf reaches hardware
• Verify EL1 kernel boots and prints "Hello World!" through the hypervisor
• Add EL2 diagnostic UART path for hypervisor-level logging separate from guest output