+.align 2
+#ifdef CONFIG_MMU
+relocate:
+ /* Relocate return address */
+ li a1, PAGE_OFFSET
+ la a2, _start
+ sub a1, a1, a2
+ add ra, ra, a1
+
+ /* Point stvec to virtual address of intruction after satp write */
+ la a2, 1f
+ add a2, a2, a1
+ csrw CSR_TVEC, a2
+
+ /* Compute satp for kernel page tables, but don't load it yet */
+ srl a2, a0, PAGE_SHIFT
+ li a1, SATP_MODE
+ or a2, a2, a1
+
+ /*
+ * Load trampoline page directory, which will cause us to trap to
+ * stvec if VA != PA, or simply fall through if VA == PA. We need a
+ * full fence here because setup_vm() just wrote these PTEs and we need
+ * to ensure the new translations are in use.
+ */
+ la a0, trampoline_pg_dir
+ srl a0, a0, PAGE_SHIFT
+ or a0, a0, a1
+ sfence.vma
+ csrw CSR_SATP, a0
+.align 2
+1:
+ /* Set trap vector to spin forever to help debug */
+ la a0, .Lsecondary_park
+ csrw CSR_TVEC, a0
+
+ /* Reload the global pointer */
+.option push
+.option norelax
+ la gp, __global_pointer$
+.option pop
+
+ /*
+ * Switch to kernel page tables. A full fence is necessary in order to
+ * avoid using the trampoline translations, which are only correct for
+ * the first superpage. Fetching the fence is guarnteed to work
+ * because that first superpage is translated the same way.
+ */
+ csrw CSR_SATP, a2
+ sfence.vma
+
+ ret
+#endif /* CONFIG_MMU */
+#ifdef CONFIG_SMP
+ /* Set trap vector to spin forever to help debug */
+ la a3, .Lsecondary_park
+ csrw CSR_TVEC, a3
+
+ slli a3, a0, LGREG
+ .global secondary_start_common
+secondary_start_common:
+
+#ifdef CONFIG_MMU
+ /* Enable virtual memory and relocate to virtual address */
+ la a0, swapper_pg_dir
+ call relocate
+#endif
+ tail smp_callin
+#endif /* CONFIG_SMP */
+
+.Lsecondary_park:
+ /* We lack SMP support or have too many harts, so park this hart */
+ wfi
+ j .Lsecondary_park
+
+END(_start)
+
+ __INIT
+ENTRY(_start_kernel)