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Commit dd189692 authored by Kevin Hao's avatar Kevin Hao Committed by Scott Wood
Browse files

powerpc: enable the relocatable support for the fsl booke 32bit kernel 



This is based on the codes in the head_44x.S. The difference is that
the init tlb size we used is 64M. With this patch we can only load the
kernel at address between memstart_addr ~ memstart_addr + 64M. We will
fix this restriction in the following patches.

Signed-off-by: default avatarKevin Hao <haokexin@gmail.com>
Signed-off-by: default avatarScott Wood <scottwood@freescale.com>
parent 1c49abec

arch/powerpc/Kconfig

+1 −1
Original line number Diff line number Diff line
@@ -884,7 +884,7 @@ config DYNAMIC_MEMSTART 


config RELOCATABLE

	bool "Build a relocatable kernel"

	depends on ADVANCED_OPTIONS && FLATMEM && 44x

	depends on ADVANCED_OPTIONS && FLATMEM && (44x || FSL_BOOKE)

	select NONSTATIC_KERNEL

	help

	  This builds a kernel image that is capable of running at the

arch/powerpc/kernel/fsl_booke_entry_mapping.S

+2 −0
Original line number Diff line number Diff line
@@ -176,6 +176,8 @@ skpinv: addi r6,r6,1 /* Increment */ 
/* 7. Jump to KERNELBASE mapping */

	lis	r6,(KERNELBASE & ~0xfff)@h

	ori	r6,r6,(KERNELBASE & ~0xfff)@l

	rlwinm	r7,r25,0,0x03ffffff

	add	r6,r7,r6



#elif defined(ENTRY_MAPPING_KEXEC_SETUP)

/*

arch/powerpc/kernel/head_fsl_booke.S

+34 −0
Original line number Diff line number Diff line
@@ -73,6 +73,30 @@ _ENTRY(_start); 
	li	r24,0			/* CPU number */

	li	r23,0			/* phys kernel start (high) */



#ifdef CONFIG_RELOCATABLE

	LOAD_REG_ADDR_PIC(r3, _stext)	/* Get our current runtime base */



	/* Translate _stext address to physical, save in r23/r25 */

	bl	get_phys_addr

	mr	r23,r3

	mr	r25,r4



	/*

	 * We have the runtime (virutal) address of our base.

	 * We calculate our shift of offset from a 64M page.

	 * We could map the 64M page we belong to at PAGE_OFFSET and

	 * get going from there.

	 */

	lis	r4,KERNELBASE@h

	ori	r4,r4,KERNELBASE@l

	rlwinm	r6,r25,0,0x3ffffff		/* r6 = PHYS_START % 64M */

	rlwinm	r5,r4,0,0x3ffffff		/* r5 = KERNELBASE % 64M */

	subf	r3,r5,r6			/* r3 = r6 - r5 */

	add	r3,r4,r3			/* Required Virtual Address */



	bl	relocate

#endif



/* We try to not make any assumptions about how the boot loader

 * setup or used the TLBs.  We invalidate all mappings from the

 * boot loader and load a single entry in TLB1[0] to map the
@@ -182,6 +206,16 @@ _ENTRY(__early_start) 


	bl	early_init



#ifdef CONFIG_RELOCATABLE

#ifdef CONFIG_PHYS_64BIT

	mr	r3,r23

	mr	r4,r25

#else

	mr	r3,r25

#endif

	bl	relocate_init

#endif



#ifdef CONFIG_DYNAMIC_MEMSTART

	lis	r3,kernstart_addr@ha

	la	r3,kernstart_addr@l(r3)

arch/powerpc/mm/fsl_booke_mmu.c

+28 −0
Original line number Diff line number Diff line
@@ -241,4 +241,32 @@ void setup_initial_memory_limit(phys_addr_t first_memblock_base, 
	/* 64M mapped initially according to head_fsl_booke.S */

	memblock_set_current_limit(min_t(u64, limit, 0x04000000));

}



#ifdef CONFIG_RELOCATABLE

notrace void __init relocate_init(phys_addr_t start)

{

	unsigned long base = KERNELBASE;



	/*

	 * Relocatable kernel support based on processing of dynamic

	 * relocation entries.

	 * Compute the virt_phys_offset :

	 * virt_phys_offset = stext.run - kernstart_addr

	 *

	 * stext.run = (KERNELBASE & ~0x3ffffff) + (kernstart_addr & 0x3ffffff)

	 * When we relocate, we have :

	 *

	 *	(kernstart_addr & 0x3ffffff) = (stext.run & 0x3ffffff)

	 *

	 * hence:

	 *  virt_phys_offset = (KERNELBASE & ~0x3ffffff) -

	 *                              (kernstart_addr & ~0x3ffffff)

	 *

	 */

	kernstart_addr = start;

	start &= ~0x3ffffff;

	base &= ~0x3ffffff;

	virt_phys_offset = base - start;

}

#endif

#endif