Re: question about adding a field into linux boot header

["Vladimir 'φ-coder/phcoder' Serbinenko" <phcoder@gmail.com>]

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On 24.03.2011 09:12, GuoMinskey wrote:
>
>
> I want to use setup_data fields of linux boot header,  but grub doesn't
> support it. So,  I cone latest grub repo (1.99) and modify grub code as
> follows:
>
>
> 1.  in include/grub/i386/linux.h,  
>
>  struct linux_kernel_header
>  {
> @@ -130,6 +144,8 @@
>    grub_uint16_t pad1;         /* Unused */
>    grub_uint32_t cmd_line_ptr; /* Points to the kernel command line */
>    grub_uint32_t initrd_addr_max;        /* Highest address for initrd */
> +  grub_uint32_t pad2[8];
> +  grub_uint64_t new_field;    <--------------  aligned to the offset
> : 0x250 as linux
>  } __attribute__ ((packed));
>
>
> 2.  grub-core/loader/i386/linux.c
>
>      I add a command by following "initrd", but simply as follows:
>
>        static grub_err_t
>            grub_cmd_test(cmd, argc, argv[])
>       {
>                  grub_printf("entering my test command\n");
>
>                  ...   //ensure kernel is loaded
>  
>                  struct linux_kernel_header *lh = (struct
> linux_kernel_header *) real_mode_mem;  
>                  lh->new_field  = 0x34FFFFFF;
>       }
>  
Could you paste the whole code in question rather than let us gues what
happens in "..." or how you set your lh variable
>     
>  when I boot GRUB with my command,  GRUB panic in relocator.
Could you please avoid paraphrasing and give exact error?
Also please try with debug=relocator and supply the output
> I print the kernel
> header, seems the header is there ( I mean real_mode_mem).   If I
> removed the line
> "lh->new_field = 0x34FFFFFF",  GRUB can work.  
>
> Did I miss something if I want pass this field into linux kernel ?
>
>
> thanks,
> -minskey 
>
>     
>
>
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> Grub-devel@gnu.org
> http://lists.gnu.org/mailman/listinfo/grub-devel
>   


-- 
Regards
Vladimir 'φ-coder/phcoder' Serbinenko



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