arch/mips/kernel/relocate_kernel.S

Source file repositories/reference/linux-study-clean/arch/mips/kernel/relocate_kernel.S

File Facts

System
Linux kernel
Corpus path
arch/mips/kernel/relocate_kernel.S
Extension
.S
Size
3616 bytes
Lines
184
Domain
Architecture Layer
Bucket
arch/mips
Inferred role
Architecture Layer: arch/mips
Status
atlas-only

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

#include <asm/asm.h>
#include <asm/asmmacro.h>
#include <asm/regdef.h>
#include <asm/mipsregs.h>
#include <asm/stackframe.h>
#include <asm/addrspace.h>

#include <kernel-entry-init.h>

LEAF(relocate_new_kernel)
	PTR_L a0,	arg0
	PTR_L a1,	arg1
	PTR_L a2,	arg2
	PTR_L a3,	arg3

	PTR_L		s0, kexec_indirection_page
	PTR_L		s1, kexec_start_address

process_entry:
	PTR_L		s2, (s0)
	PTR_ADDIU	s0, s0, SZREG

	/*
	 * In case of a kdump/crash kernel, the indirection page is not
	 * populated as the kernel is directly copied to a reserved location
	 */
	beqz		s2, done

	/* destination page */
	and		s3, s2, 0x1
	beq		s3, zero, 1f
	and		s4, s2, ~0x1	/* store destination addr in s4 */
	b		process_entry

1:
	/* indirection page, update s0	*/
	and		s3, s2, 0x2
	beq		s3, zero, 1f
	and		s0, s2, ~0x2
	b		process_entry

1:
	/* done page */
	and		s3, s2, 0x4
	beq		s3, zero, 1f
	b		done
1:
	/* source page */
	and		s3, s2, 0x8
	beq		s3, zero, process_entry
	and		s2, s2, ~0x8
	li		s6, (1 << _PAGE_SHIFT) / SZREG

copy_word:
	/* copy page word by word */
	REG_L		s5, (s2)
	REG_S		s5, (s4)
	PTR_ADDIU	s4, s4, SZREG
	PTR_ADDIU	s2, s2, SZREG
	LONG_ADDIU	s6, s6, -1
	beq		s6, zero, process_entry
	b		copy_word

done:
#ifdef CONFIG_SMP
	/* kexec_flag reset is signal to other CPUs what kernel
	   was moved to its location. Note - we need relocated address
	   of kexec_flag.  */

	bal		1f

Annotation

Implementation Notes