Errors for writing UEFI variables

Recently I got lots of questions for writing UEFI variables (ALT =), I believe it is because users wants to unlock the capability of your system.  And some blogs even mentioned how to do it with RU.

Due to the security reason, recent UEFI system firmware will not allow you to modify sensitive settings (variables).  And there is no way to change it unless you can update the SPI by a physical  programmer.

Here are what error numbers mean (UEFI spec) after you pressed CTRL-W.

0x00000000 EFI_SUCCESS               

0x00000001 EFI_LOAD_ERROR            

0x00000002 EFI_INVALID_PARAMETER     

0x00000003 EFI_UNSUPPORTED           

0x00000004 EFI_BAD_BUFFER_SIZE       

0x00000005 EFI_BUFFER_TOO_SMALL      

0x00000006 EFI_NOT_READY             

0x00000007 EFI_DEVICE_ERROR          

0x00000008 EFI_WRITE_PROTECTED       

0x00000009 EFI_OUT_OF_RESOURCES      

0x0000000a EFI_VOLUME_CORRUPTED      

0x0000000b EFI_VOLUME_FULL           

0x0000000c EFI_NO_MEDIA              

0x0000000d EFI_MEDIA_CHANGED         

0x0000000e EFI_NOT_FOUND             

0x0000000f EFI_ACCESS_DENIED         

0x00000010 EFI_NO_RESPONSE           

0x00000011 EFI_NO_MAPPING            

0x00000012 EFI_TIMEOUT               

0x00000013 EFI_NOT_STARTED           

0x00000014 EFI_ALREADY_STARTED       

0x00000015 EFI_ABORTED               

0x00000016 EFI_ICMP_ERROR            

0x00000017 EFI_TFTP_ERROR            

0x00000018 EFI_PROTOCOL_ERROR        

0x00000019 EFI_INCOMPATIBLE_VERSION  

0x0000001a EFI_SECURITY_VIOLATION    

0x0000001b EFI_CRC_ERROR             

0x0000001c EFI_END_OF_MEDIA          

0x0000001f EFI_END_OF_FILE           

0x00000020 EFI_INVALID_LANGUAGE      

0x00000021 EFI_COMPROMISED_DATA      

0x00000023 EFI_HTTP_ERROR            

 I won't be able to provide you on how to make it working, it is what it is from RU's perspective.

 

RU5.28.0397 BETA

Updated: 0396 build was removed and here is the new update 0397 build, thanks to @martin reporting the problem.

This version fixed mainly SIO and keyboard not working properly.  But I just did some very limited tests and some are not even tested.  Please note that It's not guaranteed that it works as expected.

Fix

• Fix RU can't remember SIO LDN
  
• Possibly fix the problem of reading keyboard input
• Fix the problem of showing many non-existed SIOs
• Possibly fix RU /L for SMBUS not working
  

RU /Sxx (Safe mode)

        xx stands for bits, for examples: RU /S4 means to skip SIO detection

• BIT0=1: Read MTRR only for ALT-8 CPU
  
• BIT1=1: Display readings from keyboard
  
• BIT2=1: Skip detecting SIO
• BIT3=1: Skip initializing text mode
  

Files

• Get it here
• Password:  3709180014499