Forgot to mention that this patch depends on my previous series for MMC
spl:
http://article.gmane.org/gmane.comp.boot-loaders.u-boot/96352
This one was anyway intended to initiate the discussion. If approved,
I shall create a cleaner patch.
On Friday 25 March 2011 06:42 PM, Aneesh V wrote:
> Relocation may not be needed and desirable in many cases:
> * For many boards the amount of SDRAM is fixed.
> So relocation is not needed.
> * Relocation adds un-necessary additional overhead when
> it's not needed. This delay is singificant on slower
> platforms such as FPGA
> * Many boards have ample memory. So reserving enough memory
> for Linux in the first half is not a challenge even without
> relocation
>
> Add a CONFIG option to disable relocation on platforms that
> do not need it. When this flag is enabled allocate memory
> for stack heap etc at the end of memory as usual, but U-Boot
> itself is not moved from TEXT_BASE.
>
> Additionally, -pie is removed from the final link step because
> it was causing the absolute value of all symbols coming from
> the linker script to be 0. This affects find_cmd()
>
> Tested on OMAP4430 SDP
>
> Cc: Albert Aribaud<albert.arib...@free.fr>
> Cc: Wolfgang Denk<w...@denx.de>
>
> Signed-off-by: Aneesh V<ane...@ti.com>
> ---
> arch/arm/config.mk | 2 ++
> arch/arm/lib/board.c | 5 +++++
> board/ti/sdp4430/config.mk | 9 +++++++--
> include/configs/omap4_sdp4430.h | 2 ++
> 4 files changed, 16 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm/config.mk b/arch/arm/config.mk
> index 1785e73..2315bcb 100644
> --- a/arch/arm/config.mk
> +++ b/arch/arm/config.mk
> @@ -71,5 +71,7 @@ LDSCRIPT := $(SRCTREE)/$(CPUDIR)/u-boot.lds
>
> # needed for relocation
> ifndef CONFIG_NAND_SPL
> +ifndef CONFIG_SYS_SKIP_ARM_RELOCATION
> LDFLAGS_u-boot += -pie
> endif
> +endif
> diff --git a/arch/arm/lib/board.c b/arch/arm/lib/board.c
> index 72ee108..ed3898f 100644
> --- a/arch/arm/lib/board.c
> +++ b/arch/arm/lib/board.c
> @@ -361,6 +361,7 @@ void board_init_f (ulong bootflag)
> gd->fb_base = addr;
> #endif /* CONFIG_LCD */
>
> +#ifndef CONFIG_SYS_SKIP_ARM_RELOCATION
> /*
> * reserve memory for U-Boot code, data& bss
> * round down to next 4 kB limit
> @@ -369,6 +370,7 @@ void board_init_f (ulong bootflag)
> addr&= ~(4096 - 1);
>
> debug ("Reserving %ldk for U-Boot at: %08lx\n", gd->mon_len>> 10,
> addr);
> +#endif
>
> #ifndef CONFIG_PRELOADER
> /*
> @@ -420,6 +422,9 @@ void board_init_f (ulong bootflag)
> dram_init_banksize();
> display_dram_config(); /* and display it */
>
> +#ifdef CONFIG_SYS_SKIP_ARM_RELOCATION
> + addr = _TEXT_BASE;
> +#endif
> gd->relocaddr = addr;
> gd->start_addr_sp = addr_sp;
> gd->reloc_off = addr - _TEXT_BASE;
> diff --git a/board/ti/sdp4430/config.mk b/board/ti/sdp4430/config.mk
> index c62965d..8846732 100644
> --- a/board/ti/sdp4430/config.mk
> +++ b/board/ti/sdp4430/config.mk
> @@ -28,5 +28,10 @@
> # Linux-Kernel is expected to be at 8000'8000, entry 8000'8000
> # (mem base + reserved)
>
> -# 1MB into the SDRAM to allow for SPL's bss at the beginning of SDRAM
> -CONFIG_SYS_TEXT_BASE = 0x80100000
> +# 64MB into the SDRAM
> +# Assuming a minimum of 128 MB on the board:
> +# - 64MB before U-Boot is more than enough for Linux when relocation is
> +# disabled
> +# - ~63MB after the U-Boot is more than enough for U-Boot to relocate
> +# itself without stepping on itself
> +CONFIG_SYS_TEXT_BASE = 0x84000000
> diff --git a/include/configs/omap4_sdp4430.h b/include/configs/omap4_sdp4430.h
> index fff67d8..e9f76d3 100644
> --- a/include/configs/omap4_sdp4430.h
> +++ b/include/configs/omap4_sdp4430.h
> @@ -278,4 +278,6 @@
> #define CONFIG_SYS_SPL_BSS_MAX_SIZE 0x80000 /* 512 KB */
>
> #define CONFIG_SYS_THUMB_BUILD
> +
> +#define CONFIG_SYS_SKIP_ARM_RELOCATION
> #endif /* __CONFIG_H */
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