- Joined
- Nov 25, 2015
- Messages
- 1
- Motherboard
- Apple
- CPU
- i7
- Graphics
- Radeon 6750m
- Mac
- Classic Mac
- Mobile Phone
Hi, long time reader, first time poster. I need to boot an early 2011 Macbook Pro in BIOS from a USB volume. I realize this is an atypical use-case for Clover, but rEFInd only ever boots from a GPT partition map on USB. I think this might actually be a security measure or a limitation of my Apple hardware. Does anyone know if Clover will be able to accomplish this? I don't have a good understanding of how EFI works, but it seems that booting FAT and MBR USBs is only possible when using a boot manager, which I am (rEFInd), but it is only installed to my physical disk's EFI volume, which is why I think it always only ever boots in EFI mode and never reverts to legacy/BIOS emulation even when booting to a FAT USB. It could also be I'm wrong here and that my memory of attempting this before is incorrect, so feel free to set me straight on that.
I'm reading that legacy/BIOS emulation boot will work from a physical disk with an MBR partition map or with hybrid MBR/GPT partition maps, but I would like to avoid changing my existing GPT partition map to an MBR partition map and also to avoid the risk of potentially making my currently bootable GPT partition map non-bootable by attempting hybridizing it with MBR. I had already attempted this and failed, so I'm feeling a little lucky I'm booting at the moment.
Anyhow, my purpose in this endeavor is dumping my graphics card firmware to a file, which isn't possible unless I'm booting in legacy/BIOS mode. I need my firmware dump because Xorg won't handle my graphics adapter properly without it and Apple's UEFI implementation prevents Xorg from dumping it.
Sorry if this question has been asked before. I'm sure I have already found answer to my questions after reading similar posts, but the overwhelmingly numerous details are so fleeting to my encumbered memory and the guides on EFI/BIOS trickery are quite lengthy, so maybe someone can just get me on the right path here.
tl;dr: should I just give up trying to force my Mac into BIOS mode from a USB boot? Is it only possible when booting from a physical disk?
Edit:
Alternatively, if anyone has a copy of a Radeon 6750m firmware dump for a macbookpro8,2 (early 2011), I will give those a try. There don't seem to be any posted online.
I'm reading that legacy/BIOS emulation boot will work from a physical disk with an MBR partition map or with hybrid MBR/GPT partition maps, but I would like to avoid changing my existing GPT partition map to an MBR partition map and also to avoid the risk of potentially making my currently bootable GPT partition map non-bootable by attempting hybridizing it with MBR. I had already attempted this and failed, so I'm feeling a little lucky I'm booting at the moment.
Anyhow, my purpose in this endeavor is dumping my graphics card firmware to a file, which isn't possible unless I'm booting in legacy/BIOS mode. I need my firmware dump because Xorg won't handle my graphics adapter properly without it and Apple's UEFI implementation prevents Xorg from dumping it.
Sorry if this question has been asked before. I'm sure I have already found answer to my questions after reading similar posts, but the overwhelmingly numerous details are so fleeting to my encumbered memory and the guides on EFI/BIOS trickery are quite lengthy, so maybe someone can just get me on the right path here.
tl;dr: should I just give up trying to force my Mac into BIOS mode from a USB boot? Is it only possible when booting from a physical disk?
Edit:
Alternatively, if anyone has a copy of a Radeon 6750m firmware dump for a macbookpro8,2 (early 2011), I will give those a try. There don't seem to be any posted online.
