[U-Boot-Users] [PATCH] Fill fw_arg3

[Detlev Zundel]

Hi Florian,

> This patch allows MIPS based Linux kernels to do runtime bootloader detection 
> by reading Linux's fw_arg3 in the PROM code (for instance) filled with the 
> magic number "UBOO". This may not be really useful for other boards than MIPS 
> and in particular those that use several different bootloaders (like 
> ADM5120).
>
> Signed-off-by: Florian Fainelli <florian.fainelli at telecomint.eu>
> --
>
> diff --git a/lib_mips/mips_linux.c b/lib_mips/mips_linux.c
> index 952d5a9..0823bc0 100644
> --- a/lib_mips/mips_linux.c
> +++ b/lib_mips/mips_linux.c
> @@ -33,6 +33,8 @@ DECLARE_GLOBAL_DATA_PTR;
>  #define	LINUX_MAX_ENVS		256
>  #define	LINUX_MAX_ARGS		256
>  
> +#define UBOOT_MAGIC_NUMBER	0x55424F4F	/* UBOO */
> +
>  #ifdef CONFIG_SHOW_BOOT_PROGRESS
>  # include <status_led.h>
>  # define SHOW_BOOT_PROGRESS(arg)	show_boot_progress(arg)
> @@ -213,7 +215,7 @@ void do_bootm_linux (cmd_tbl_t * cmdtp, int flag, int argc, char *argv[],
>  	/* we assume that the kernel is in place */
>  	printf ("\nStarting kernel ...\n\n");
>  
> -	theKernel (linux_argc, linux_argv, linux_env, 0);
> +	theKernel (linux_argc, linux_argv, linux_env, UBOOT_MAGIC_NUMBER);
>  }
>  
>  static void linux_params_init (ulong start, char *line)

I know U-Boot is magic - but why have more than needed?

[dzu at pollux u-boot]$ grep IH_MAGIC include/*
include/image.h:#define IH_MAGIC        0x27051956      /* Image Magic Number           */
[dzu at pollux u-boot]$ grep 27051956 /usr/share/magic
0       belong  0x27051956      u-boot/PPCBoot image

Cheers
  Detlev

-- 
... does Linux have a better [security] track record than MS? Damn right it
does. We've had fewer problems, and I think there are more people out there
standing up for what's right anyway. Less PR people deathly afraid of rocking
the boat. Better technology, and fewer horrid design mistakes. [Linus Torvalds]
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