Hi Jim, > some BIOSes have already been replaced with UEFI. AMI has been using it for > years, and now it is the only kind of "BIOS" supported in their diags suite. > ack! I wanted to have that suite someday for testing systems... > > http://www.ami.com/products/product.cfm?CatID=3&SubID=23&ProdID=147 > > some manufacturers may still use legacy BIOS possibly, but it looks like > things > are definitely moving towards UEFI+GPT. > > for the DOS folk, this is maybe a wake-up call to start implementing > additional partitioning schemes? (by the way, the last version of fdisk I > used > is broken, it started creating empty partitions)
Which version is this? > I still have some utilities that are written in DOS+BIOS calls. so I am not > sure what to do next. I don't have $2500 lying about to implement UEFI API > calls (or is it $2500 to implement UEFI rather than call the Interface?). > What > think ye? > > someone (me?) probably needs to contact UEFI and ask them if calling the API > requires a $2500 fee or not, and whether or not a .c/.cpp+.h source files are > available for the Interface. I do not think that you have to pay to CALL the UEFI BIOS... This is probably for those who WRITE UEFI certified BIOSes? Or to get some official docs? > GPT allows up to 128 partitions on a disk, whereas MBR only allows 4. BIOS > has > a limited number of functions, whereas UEFI can have its functionality > expanded > by placing it partially on a disk using a certain type of filesystem such as > FAT32. MBR allows a chain of infinitely many logical partitions. It is just that the MBR allows only 4 primary partitions. > there is a backup copy of the partition table in GPT in case of something > catastrophic. > > The Mac also uses UEFI+GPT. Well, here are some notes about BASIC GPT / EFI partitioning: Luckily EFI does not seem to be complicated - EFI partitions ignore all CHS values and have a partition ID of 0xef, and classic partitions can coexist with them... Header, padded to suitable power of 2 size: qword 0x5452415020494645 / EFI PART dword 0x00010000 version dword header size dword header crc32 dword 0 qword lba address of THIS sector qword lba address of alternate header(?) qword first data block of partition? qword last data block of partition? 16 bytes GUID to uniquely identify disk qword lba address of GUID partition entry array dword array size dword array crc32 padding Partition entry, 128 bytes each: 16 bytes partition type (0 if unused) 16 bytes GUID to very uniquely identify partition qword lba address of partition start qword lba address of partition end qword attribute bits (only low bit required?) (high word reserved, middle 47 bits undefined?) 72 bytes UTF-8 (correct?) partition name string A DOS kernel could easily implement this. Regards, Eric ------------------------------------------------------------------------------ Forrester recently released a report on the Return on Investment (ROI) of Google Apps. They found a 300% ROI, 38%-56% cost savings, and break-even within 7 months. Over 3 million businesses have gone Google with Google Apps: an online email calendar, and document program that's accessible from your browser. Read the Forrester report: http://p.sf.net/sfu/googleapps-sfnew _______________________________________________ Freedos-devel mailing list Freedos-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-devel
