Gavin Xue has created UefiTool:
A simple UEFI tool for debugging.
Print (L”Help info:\n”);
Print (L” UefiTool.efi -H\n\n”);
Print (L”Read MSR register:\n”);
Print (L” UefiTool.efi RDMSR [MSRIndex] [OPTION: -A | -P]\n\n”);
Print (L”Write MSR register:\n”);
Print (L” UefiTool.efi WRMSR [MSRIndex] [MSRValue]\n\n”);
Print (L”Read CPUID:\n”);
Print (L” UefiTool.efi CPUID [CPUID_Index] [CPUID_SubIndex]\n\n”);
Print (L”Read GDTR resister:\n”);
Print (L” UefiTool.efi -SGDT\n\n”);
Print (L”Read CR resister:\n”);
Print (L” UefiTool.efi -CR\n\n”);
https://github.com/vinxue/UefiTool
Not to be confused with UEFITool: