Help! I can't write at 0xFE000000

[nifanfa]

https://github.com/nifanfa/CS2ASM
https://github.com/nifanfa/CS2ASM/blob/ ... /Paging.cs
https://github.com/nifanfa/CS2ASM/blob/ ... yPoint.asm
here is the source code

[Octocontrabass]

i can access 0xFD000000 before entering long mode

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size 8

What happens if you use uint instead of ulong?

[nifanfa]

i can access 0xFD000000 before entering long mode

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size 8

What happens if you use uint instead of ulong?

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Invalid access at addr 0xFD000000, size 4, region '(null)', reason: rejected

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            Paging.Map(0xFD000000, 0xFD000000);
            uint val = 0;
            asm("mov edi,0xFD000000");
            asm("mov dword [edi],1024");
            asm("mov eax,[edi]");
            asm("mov {val},eax");
            Console.WriteLine(((ulong)val).ToString());

[Octocontrabass]

You're disabling MMIO!

You don't need to write anything to the command register. Firmware enables all PCI devices before it loads your bootloader.

[nifanfa]

You're disabling MMIO!

You don't need to write anything to the command register. Firmware enables all PCI devices before it loads your bootloader.

THANK YOU SO MUCH!!!
I CAN'T EXPRESS HOW EXCITED I AM!!!

i thought

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WriteRegister16(device.Bus, device.Slot, device.Function, 0x04, 0x04);

is to enable the pci mmio.

[klange]

i thought

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WriteRegister16(device.Bus, device.Slot, device.Function, 0x04, 0x04);

is to enable the pci mmio.

Writing 0x04 to the command register will enable bus mastering, and disable everything else. Don't let the name confuse you, the register does not work by taking 'commands' - it's a bitfield so you need to maintain all of the other bits as you set or unset new ones.

Good catch, Octocontrabass!