慢慢欣赏arm64内核启动7 primary_entry之el2_setup代码第五部分
分析代码 /* EL2 debug */mrs x1, id_aa64dfr0_el1sbfx x0, x1, #ID_AA64DFR0_PMUVER_SHIFT, #4cmp x0, #1b.lt 4f // Skip if no PMU presentmrs x0, pmcr_el0 // Disable debug access trapsubfx x0, x0, #11, #5 // to EL2 and allow access to 4:csel x3, xzr, x0, …
2025-07-30