慢慢欣赏arm64内核启动27 primary_entry之__primary_switch代码第三部分

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已于 2024-10-14 08:59:05 修改 · 359 阅读

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#linux

于 2024-10-12 09:24:58 首次发布

展示代码

#ifdef CONFIG_RELOCATABLE
#ifdef CONFIG_RELR
	mov	x24, #0				// no RELR displacement yet
#endif
	bl	__relocate_kernel
#ifdef CONFIG_RANDOMIZE_BASE
	ldr	x8, =__primary_switched
	adrp	x0, __PHYS_OFFSET
	blr	x8

	/*
	 * If we return here, we have a KASLR displacement in x23 which we need
	 * to take into account by discarding the current kernel mapping and
	 * creating a new one.
	 */
	pre_disable_mmu_workaround
	msr	sctlr_el1, x20			// disable the MMU
	isb
	bl	__create_page_tables		// recreate kernel mapping

	tlbi	vmalle1				// Remove any stale TLB entries
	dsb	nsh
	isb

	msr	sctlr_el1, x19			// re-enable the MMU
	isb
	ic	iallu				// flush instructions fetched
	dsb	nsh				// via old mapping
	isb

	bl	__relocate_kernel
#endif
#endif
	ldr	x8, =__primary_switched
	adrp	x0, __PHYS_OFFSET
	br	x8
SYM_FUNC_END(__primary_switch)