[U-Boot] [PATCH] mpc85xx shrink boot block page to 1M

[Liu Dave]

> Use CONFIG_SYS_BOOT_BLOCK_{EPN,RPN,PAGESZ} in start.S for the boot
> block TLB for AS=1 mapping.  Reduce the default size from 16M to 1M.
> 
> Change bne to blt in 85xx clear_bss to protect against the pointer
> never being equal to _end if _end is not word aligned.
> 
> Signed-off-by: Ed Swarthout <Ed.Swarthout at freescale.com>
> ---
> This is an alternate patch to Dave Liu's:
> 2008-12-16 [PATCH 1/3] 85xx: Fix the boot window issue
> 
> It has the additional feature of allowing the board file
> to override the mapping values without additional code.
> 
> 
>  cpu/mpc85xx/start.S |   28 ++++++++++++++++++++--------
>  1 files changed, 20 insertions(+), 8 deletions(-)
> 
> diff --git a/cpu/mpc85xx/start.S b/cpu/mpc85xx/start.S
> index 8fa0ff7..7e11f35 100644
> --- a/cpu/mpc85xx/start.S
> +++ b/cpu/mpc85xx/start.S
> @@ -188,15 +188,27 @@ _start_e500:
>  	lis     r6,FSL_BOOKE_MAS0(1, 15, 0)@h
>  	ori     r6,r6,FSL_BOOKE_MAS0(1, 15, 0)@l
>  
> -	lis     r7,FSL_BOOKE_MAS1(1, 1, 0, 1, BOOKE_PAGESZ_16M)@h
> -	ori     r7,r7,FSL_BOOKE_MAS1(1, 1, 0, 1, BOOKE_PAGESZ_16M)@l
> +#ifndef CONFIG_SYS_BOOT_BLOCK_EPN
> +#define CONFIG_SYS_BOOT_BLOCK_EPN (TEXT_BASE & 0xfff00000) 
> /* Align to 1MB */
> +#endif
> +#ifndef CONFIG_SYS_BOOT_BLOCK_RPN
> +#define CONFIG_SYS_BOOT_BLOCK_RPN 0xfff00000
> +#endif
> +#ifndef CONFIG_SYS_BOOT_BLOCK_PAGESZ
> +#define CONFIG_SYS_BOOT_BLOCK_PAGESZ	BOOKE_PAGESZ_1M
> +#endif
>  
> -	/* Align the mapping to 16MB */
> -	lis     r8,FSL_BOOKE_MAS2(TEXT_BASE & 0xff000000, 
> (MAS2_I|MAS2_G))@h
> -	ori     r8,r8,FSL_BOOKE_MAS2(TEXT_BASE & 0xff000000, 
> (MAS2_I|MAS2_G))@l
> +	lis     r7,FSL_BOOKE_MAS1(1, 1, 0, 1, 
> CONFIG_SYS_BOOT_BLOCK_PAGESZ)@h
> +	ori     r7,r7,FSL_BOOKE_MAS1(1, 1, 0, 1, 
> CONFIG_SYS_BOOT_BLOCK_PAGESZ)@l
>  
> -	lis     r9,FSL_BOOKE_MAS3(0xff000000, 0, 
> (MAS3_SX|MAS3_SW|MAS3_SR))@h
> -	ori     r9,r9,FSL_BOOKE_MAS3(0xff000000, 0, 
> (MAS3_SX|MAS3_SW|MAS3_SR))@l
> +	lis     r8,FSL_BOOKE_MAS2(CONFIG_SYS_BOOT_BLOCK_EPN, 
> (MAS2_I|MAS2_G))@h
> +	ori     r8,r8,FSL_BOOKE_MAS2(CONFIG_SYS_BOOT_BLOCK_EPN,
> +				(MAS2_I|MAS2_G))@l
> +
> +	lis     r9,FSL_BOOKE_MAS3(CONFIG_SYS_BOOT_BLOCK_RPN, 0,
> +				(MAS3_SX|MAS3_SW|MAS3_SR))@h
> +	ori     r9,r9,FSL_BOOKE_MAS3(CONFIG_SYS_BOOT_BLOCK_RPN, 0,
> +				(MAS3_SX|MAS3_SW|MAS3_SR))@l
>  
>  	mtspr   MAS0,r6
>  	mtspr   MAS1,r7
> @@ -917,7 +929,7 @@ clear_bss:
>  	stw	r0,0(r3)
>  	addi	r3,r3,4
>  	cmplw	0,r3,r4
> -	bne	5b
> +	blt	5b
>  6:
>  
>  	mr	r3,r9		/* Init Data pointer		*/
> -- 
> 1.5.6.5

If we reduce to 1M, that means the u-boot image size must less than 1MB.
I wish we reduce to 4M.