similar to: [PATCH] efi: leaving long mode in kernel_jump routine

On Tue, Aug 4, 2015 at 2:55 AM, Thomas Letan via Syslinux <syslinux at zytor.com> wrote: > Syslinux 6.03 (efi64) fails to boot a 32-bit kernel. The way Syslinux > leaves long mode in kernel_jump assembly routine does not follow AMD64 > specifications. More precisely: > 1. After setting a new GADT, `cs` has to be refresh by doing a long > jump, but it is not > 2. Other

> On Tue, Aug 4, 2015 at 2:55 AM, Thomas Letan via Syslinux <syslinux at zytor.com> wrote: > Syslinux 6.03 (efi64) fails to boot a 32-bit kernel. The way Syslinux > leaves long mode in kernel_jump assembly routine does not follow AMD64 > specifications. More precisely: > 1. After setting a new GADT, `cs` has to be refresh by doing a long > jump, but it is not > 2.

From: Sylvain Gault <sylvain.gault at gmail.com> Missing */ at the end of a comment. Signed-off-by: Sylvain Gault <sylvain.gault at gmail.com> --- efi/x86_64/linux.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/efi/x86_64/linux.S b/efi/x86_64/linux.S index 972c0b2..29dde94 100644 --- a/efi/x86_64/linux.S +++ b/efi/x86_64/linux.S @@ -27,7 +27,7 @@ kernel_jump:

>>> > Syslinux 6.03 (efi64) fails to boot a 32-bit kernel. The way Syslinux > leaves long mode in kernel_jump assembly routine does not follow AMD64 > specifications. More precisely: > 1. After setting a new GADT, `cs` has to be refresh by doing a long > jump, but it is not > 2. Other segments have to be updated, but they are not > 3. Disabling paging has to be

On Fri, 11 Sep 2015 03:59:09 +0200 celelibi--- via Syslinux <syslinux at zytor.com> wrote: > From: Sylvain Gault <sylvain.gault at gmail.com> > > Missing */ at the end of a comment. > > Signed-off-by: Sylvain Gault <sylvain.gault at gmail.com> Reviewed-by: Paulo Alcantara <pcacjr at zytor.com> Thanks, Paulo > --- > efi/x86_64/linux.S | 2 +- >

On Tue, Aug 4, 2015 at 2:55 AM, Thomas Letan via Syslinux <syslinux at zytor.com> wrote: > Syslinux 6.03 (efi64) fails to boot a 32-bit kernel. The way Syslinux > leaves long mode in kernel_jump assembly routine does not follow AMD64 > specifications. More precisely: > 1. After setting a new GADT, `cs` has to be refresh by doing a long > jump, but it is not > 2. Other

2015-08-23 20:09 UTC+02:00, Gene Cumm via Syslinux <syslinux at zytor.com>: > On Tue, Aug 4, 2015 at 2:55 AM, Thomas Letan via Syslinux > <syslinux at zytor.com> wrote: >> Syslinux 6.03 (efi64) fails to boot a 32-bit kernel. The way Syslinux >> leaves long mode in kernel_jump assembly routine does not follow AMD64 >> specifications. More precisely: >> 1.

On Tue, Aug 4, 2015 at 2:55 AM, Thomas Letan via Syslinux <syslinux at zytor.com> wrote: > Syslinux 6.03 (efi64) fails to boot a 32-bit kernel. The way Syslinux > leaves long mode in kernel_jump assembly routine does not follow AMD64 > specifications. More precisely: > 1. After setting a new GADT, `cs` has to be refresh by doing a long > jump, but it is not > 2. Other

Actually your Syslinux config is less relevant than the kernel config file. Indeed Syslinux infers the method to use from the kernel image itself. I assume the .config is public. I will take a look as soon as I can Thomas Le 04/08/2015 14:09, intrigeri via Syslinux a ?crit : > Thomas Letan via Syslinux wrote (04 Aug 2015 09:27:38 GMT) : >> Are you using EFI Handover Protocol? >

Hi > Maybe I'm missing something, but this has been working flawlessly for > us in Tails so far. What exactly fails? Are you using EFI Handover Protocol? It might explain the difference Thomas

> Syslinux 6.03 (efi64) fails to boot a 32-bit kernel. The way Syslinux > leaves long mode in kernel_jump assembly routine does not follow AMD64 > specifications. More precisely: > 1. After setting a new GADT, `cs` has to be refresh by doing a long > jump, but it is not > 2. Other segments have to be updated, but they are not > 3. Disabling paging has to be done before

>>> > Have you tested it? > Have you checked that efi64 loading 64bit kernels is OK from a kernel_jump point of view? For a 32-bit kernel, I did. For a 64-bit kernel, I didn't but I see no reason it should failed. I will try just to be sure. <<< Unfortunately at the moment I cannot test your finding (probably Gene will). Now that you are immerse in the topic it

Hi, Thomas Letan via Syslinux wrote (04 Aug 2015 06:55:48 GMT) : > Syslinux 6.03 (efi64) fails to boot a 32-bit kernel. Maybe I'm missing something, but this has been working flawlessly for us in Tails so far. What exactly fails? Cheers, -- intrigeri

Thomas Letan via Syslinux wrote (04 Aug 2015 09:27:38 GMT) : > Are you using EFI Handover Protocol? What we're doing is: label livefailsafe menu label Live (failsafe) kernel /live/vmlinuz2 append initrd=/live/initrd2.img boot=live config live-media=removable apparmor=1 security=apparmor nopersistent noprompt timezone=Etc/UTC block.events_dfl_poll_msecs=1000 splash noautologin

Hi > The effect was simply that the (physical) machine rebooted exactly on > the wrmsr instruction. The result of my investigation was that the > code wasn't following the protocol (by intel and by AMD) for leaving > long mode as pointed out by Thomas Letan. Indeed it's exactly that! > I think qemu and some processors are just more permissive and allow > the current

Hi! Sorry for not responding earlier. I was planning to but I lack time. > AFAIK it seems this patch is even necessary for new kernels in the case > EFI64 boots a 32 Bit kernel, right? I think it is, yes. I will try to do more test myself. I hope I will be able to tell more this week.

On mageia I'm using the following patch https://svnweb.mageia.org/packages/cauldron/syslinux/current/SOURCES/syslinux-nogit.patch?revision=600959&view=markup If it does solve your issue to, I could try pushing it into the repo. 2015-09-16 8:44 GMT+02:00 Thomas Letan via Syslinux <syslinux at zytor.com>: > Hi. > > Sometimes, it may happen that we do not want to clone a

Thank you for the info, I tested the latest version Syslinux 6.03 (64 bit) and it didn't work. the boot loader text shows up, then the screen freezes. maybe it works only on some specific boards/CPUs. Thank you for the reply's, the problem is now solved by using another Bootloader. Best Regards, On 29.10.18 15:29, Letan Thomas wrote: > I was able to successfully boot 32-bit

Hello Ady thank you very much for the accurate reply and for saving my time :-) Best Regards, On 17.10.18 18:06, Ady Ady via Syslinux wrote: >> is it possible to boot a 32 Bit Kernel on 64 EFI firmware with Syslinux? > > In theory, booting 32-bit kernels from 64-bit EFI is supposed to be > supported by "efi64/efi/syslinux.efi" since 2013Jun. > > In practice:

To describe the virtual topology in relation to a virtio-iommu device, ACPI-based systems use a "paravirtualized IOMMU" IORT node. Add support for it. This is a RFC because the IORT specification doesn't describe the paravirtualized node at the moment, it is only provided as an example in the virtio-iommu spec. What we need to do first is confirm that x86 kernels are able to use the