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> MenuetOS > The distinction between BIOS and UEFI |
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bzt 12 May 2024, 21:49
As fas as I know, MenuetOS can only be booted on UEFI with Easyboot. Now that boot loader puts a lot of effort into making your life easier, so it does you a favour to transparently convert the memory map for you.
Therefore there's no difference in the BIOS/UEFI memory map as far as MenuetOS concerned, all you'll ever see is E820 area type codes. (FYI, there's no difference in the framebuffer, VBE/GOP, the ACPI pointer etc. either, It Just Works (TM), the actual firmware is Somebody Else's Problem (TM)). |
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12 May 2024, 21:49 |
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Ville 13 May 2024, 11:33
Here. Instead of 26/5, Im using 26/15 so its easier to detect the size of the e820 formatted memory map.
Code: read_parameters: ; Read and display memory map mov rdx , 20 shl 32 + 50 mov r15 , 0 newread: mov rax , 26 mov rbx , 15 mov rcx , r15 int 0x60 mov rcx , rax mov rax , 47 mov rbx , 16*65536+256 mov rsi , 0 int 0x60 add r15 , 8 add rdx , 12 cmp rcx , -1 jne newread ; Read and display BIOS/UEFI boot mov rax , 26 mov rbx , 13 mov rcx , 0x100 int 0x60 mov rbx , string_bios mov rcx , string_uefi cmp rax , 1 cmove rbx , rcx mov rax , 4 mov rcx , 150 mov rdx , 50 mov rsi , 0x000000 mov r9 , 1 int 0x60 ret string_bios: db 'BIOS boot',0 string_uefi: db 'UEFI boot',0 |
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13 May 2024, 11:33 |
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CandyMan 13 May 2024, 20:19
Thanks Ville.
Is the structure returned in the case of UEFI (system function 26/15) also 3 * QWord ? To check how it works, please run NDN and select from the main menu -> Utilities -> Memory Map https://megawrzuta.pl/download/b463e8b707f681749417e6861d25addd.html |
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13 May 2024, 20:19 |
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Ville 13 May 2024, 22:06
It seems that Chrome prevents me from downloading the file (security reasons). But yes, the format is the same for both BIOS and UEFI - 3 x Qword.
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13 May 2024, 22:06 |
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