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   alt.os.development      Operating system development chatter      4,255 messages   

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   Message 4,090 of 4,255   
   wolfgang kern to All   
   UEFI GPT   
   20 Jan 24 05:16:18   
   
   From: nowhere@never.at   
      
   my attempt to manually create a complete UEFI startup with KESYS hexwork   
   still encounter many obstacles :)   
      
   please tell me what I may have missed and what's different to your settings.   
   TIA   
   __   
   wolfgang   
      
   what I have so far:   
   (almost all is in hex, b/w/q/dq/qq mean 8/16/32/64/128 bit)   
   [LBA_0] MBR:   
   0000 ... all zero   
   01BE xx xx xx EE yy yy yy 01 00 00 00 ss ss ss ss   
         x = start CHS usually 1   
         y = end   CHS usually FFFFFF   
         0000_0001 start LBA of GPT image   
         0000_0004 size of this GPT image LBA_0,1,2,3 (in sectors)   
                   specs want much more to waste   
   01CE ... all zero   
   01FE 55 AA   
   ------------------   
   [LBA_1] GPT header   
   000 45 46 49 20 50 41 52 54 ;"EFI PART" Signature   
   008 00 00 01 00   Revision for GPT version 1.0   
                      (through at least UEFI version 2.3.1),   
   00C 5C 00 00 00   Header size (in bytes)   
   010 q  0          CRC32 of header (offset +0 up to header size),   
                      with this field zeroed during calculation   
   014 q  0          Reserved; must be zero   
   018 dq ....       Current LBA (location of this header copy)   
   020 dq ....       Backup LBA (location of the other header copy)   
   028 dq 4          First usable LBA for partitions (primary last LBA + 1)   
        specs say minimum 6 for 4K sectors and 34dec for 512 byte sectors   
        what a waste ...   
   030 dq ....       Last usable LBA (secondary partition first LBA - 1)   
   038 dq ???        Disk GUID (also referred as UUID on UNIXes)   
   048 dq 2          Starting LBA of array of partition entries   
                      (always 2 in primary)   
   050 q  00000004   Number of partition entries in array   
   054 q  00000080   Size of a single partition entry (usually 128)   
   058 q  0          CRC32 of partition array   
   05C..end of sector; all ZERO   
         (420 bytes for 512 byte sectors; but more with larger sector sizes)   
   ---------------------------   
   [LBA_2] I'd have only four partition entries assigned   
   GUID partition entry format [128 byte each]   
   000 qq          Partition type GUID   
   1.    ??? boot part                                    ;FAT32   
   2.    "KESYS 64 ddmm2024" to be declared global unique ;KESYS64   
   3.    28 73 C1 2A-1F F8 D2 11  BA 4B 00 A0 C9 3E C9 3B ;EFI   
   4.    16 E3 C9 E3 5C 0B B8 4D  81 7D F9 2D F0 02 15 AE ;M$ reserved   
          ???                                              ;or NTFS   
   010 qq  ???     Unique partition GUID   
   020 dq  4/x/x/x First LBA (specs say 6 or 34 for first partition)   
   028 dq          Last LBA (inclusive, usually odd)   
   030 dq         Attribute flags   
   038 str        72 bytes Partition name (36 UTF-16LE code units)   
      
   The 64-bit partition table attributes are shared between 48-bit common   
   attributes for all partition types, and 16-bit type-specific attributes.   
      
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)   

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