> The 4.2.2 gcc in the ELDK42 release doesn't like the direct SP
> load using a constant in tegra2_start. Break it up into 4 loads
> using mov & orr.
>
> Tested on my Seaboard T20-A03, U-Boot loads and runs OK. Also
> compiled all tegra2 builds with both gcc 4.2.2 and 4.4.1 OK.
>
> Signed-off-by: Tom Warren <[email protected]>
> ---
> arch/arm/cpu/armv7/tegra2/ap20.c | 25 ++++++++++++++++++++-----
> 1 files changed, 20 insertions(+), 5 deletions(-)
>
> diff --git a/arch/arm/cpu/armv7/tegra2/ap20.c
> b/arch/arm/cpu/armv7/tegra2/ap20.c index 4c44bb3..d2bc0d5 100644
> --- a/arch/arm/cpu/armv7/tegra2/ap20.c
> +++ b/arch/arm/cpu/armv7/tegra2/ap20.c
> @@ -298,11 +298,26 @@ void tegra2_start(void)
> writel(0xC0, &pmt->pmt_cfg_ctl);
>
> /*
> - * If we are ARM7 - give it a different stack. We are about to
> - * start up the A9 which will want to use this one.
> - */
> - asm volatile("ldr sp, =%c0\n"
> - : : "i"(AVP_EARLY_BOOT_STACK_LIMIT));
> + * If we are ARM7 - give it a different stack. We are about to
> + * start up the A9 which will want to use this one.
> + */
> + /*
> + * Note that the 'ldr sp,CONSTANT' version, below, doesn't
> + * work on gcc 4.2.2 (ELDK42), but does on gcc 4.4.1 and above.
> + * The work-around is to use the (ugly) 4-pass mov/orr below.
> + *
> + * asm volatile("ldr sp, =%c0\n" : :
> + * "i"(AVP_EARLY_BOOT_STACK_LIMIT));
> + */
> +
> + asm volatile("mov sp, %0"
> + : : "i"(AVP_EARLY_BOOT_STACK_LIMIT & 0xFF));
> + asm volatile("orr sp, %0"
> + : : "i"(AVP_EARLY_BOOT_STACK_LIMIT & 0xFF00));
> + asm volatile("orr sp, %0"
> + : : "i"(AVP_EARLY_BOOT_STACK_LIMIT & 0xFF0000));
> + asm volatile("orr sp, %0"
> + : : "i"(AVP_EARLY_BOOT_STACK_LIMIT & 0xFF000000));
asm volatile("mov sp, %0"::"r"(AVP_EARLY_BOOT_STACK_LIMIT)); won't work?
M
>
> start_cpu((u32)_start);
> halt_avp();
_______________________________________________
U-Boot mailing list
[email protected]
http://lists.denx.de/mailman/listinfo/u-boot
