delorie.com/archives/browse.cgi   search  
Mail Archives: djgpp/1998/05/02/19:55:06

Message-ID: <354B4F06.C8B1B76@zfs.lg.ua>
Date: Sat, 02 May 1998 19:51:18 +0300
From: "Kirpa S.I." <kirpa AT zfs DOT lg DOT ua>
Reply-To: kirpa AT zfs DOT lg DOT ua
MIME-Version: 1.0
To: WT <gnatwt AT mailexcite DOT com>
CC: djgpp AT delorie DOT com
Subject: Re: Problem with integer declaration?
References: <354AB827 DOT 8EE19C9D AT mailexcite DOT com>

> I am trying to write a short program to detect VESA VBE and output
> information about the video card. I declared a struct of 512 bytes to be
> used as a buffer for vbe_info_block. The strange thing is that when I
> printed sizeof(vbe_info_block) it gave me 516 bytes instead of 512. I am
> sure my struct is correct because I've checked it many times. This is
> how the struct is declared :
>
> typedef
>   struct {
>     unsigned int vbe_signature; /* VBE Signature */
>     unsigned short vbe_version; /* VBE Version */
>     unsigned int oem_string_ptr; /* Pointer to OEM info */
>     unsigned int capabilities; /* Capabilities of graphics controller */
>
>     unsigned int video_mode_ptr; /* Pointer to VideoModeList */
>     unsigned short total_memory; /* Number of 64kb memory blocks */
>     /* Added for VBE 2.0 */
>     unsigned short oem_software_rev; /* VBE implementation Software
> revision */
>     unsigned int oem_vendor_name_ptr; /* Pointer to Vendor Name String
> */
>     unsigned int oem_product_name_ptr; /* Pointer to Product Name String
> */
>     unsigned int oem_product_rev_ptr; /* Pointer to Product Revision
> String */
>     unsigned char reserved[222]; /* Reserved for VBE implementation
> scratch area */
>     unsigned char oem_data[256]; /* Data Area for OEM Strings */
>   } vbe_info_block;
>
> Could it be something wrong with the int declaration? Please help!

 Yes! Of course!
You mast declare this structure like that:

#define BYTE unsigned char
#define WORD unsigned short
#define DWORD  unsigned long

typedef
  struct {
    DWORD vbe_signature; /* VBE Signature */
    WORD vbe_version; /* VBE Version */
    WORD oem_string_ptr; /* Pointer to OEM info */
    WORD capabilities; /* Capabilities of graphics controller */
  . . .
}  vbe_info_block  __attribute__((packed));

-----------------------^^^^^^^^^^^^^^^^^^^^^

--
        ๋ษาะม ๓.้.   kirpa AT zfs DOT lg DOT ua




- Raw text -


  webmaster     delorie software   privacy  
  Copyright ฉ 2019   by DJ Delorie     Updated Jul 2019