[x86 question] invalid conversion of bootloader_type and bootloader_version ??

[x86 question] invalid conversion of bootloader_type and bootloader_version ??

[Jongman Heo]

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Hi, all,

While looking at x86 boot code (arch/x86/kernel/setup.c), I got confused due to bootloader_type and bootloader_version conversion.

I've only checked GRUB and U-Boot bootloader code.

1. GRUB 2
    type_of_loader setting = 0x72
-> bootloader_type = 0x72, bootloader_version = 0x2

2. U-Boot
    type_of_loader setting = 0x8
-> bootloader_type = 0x8, bootloader_version = 0x8

3. example in Documentation/x86/boot.txt
    type_of_loader  = 0xE4, ext_loader_type = 0x05, ext_loader_ver = 0x23, for T = 0x15, V = 0x234
-> bootloader_type = 0x154, bootloader_version = 0x234

So, for GRUB 2 and the example bootloader, T != bootloader_type. 
Is this intended?
First I thought that bootloader_type and bootloader_version should match with T and V configured in the bootloader. 

This would not bring any real world issue, but I'm just curious.

Regards,
Jongman Heo.
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