ric ; Brijesh Singh ; Wang, Jian
> J ; Wu, Hao A
> ; Bi, Dandan
> Subject: Re: [edk2-devel] [RFC PATCH v3 33/43] MdeModulePkg: Reserve a 16-bit
> protected mode code segment descriptor
>
> On 12/12/19 12:57 AM, Ni, Ray via Groups.Io wrote:
> > Is the 16bit code segment d
On 12/12/19 12:57 AM, Ni, Ray via Groups.Io wrote:
> Is the 16bit code segment descriptor needed in early DXE before CpuDxe (DXE
> MP)?
I don't believe it is. I did this to keep all of the CS descriptors
consistent since the ones here seemed to line up with the ones in
UefiCpuPkg/CpuDxe/CpuGdt.c.
Is the 16bit code segment descriptor needed in early DXE before CpuDxe (DXE MP)?
> -Original Message-
> From: Tom Lendacky
> Sent: Thursday, November 21, 2019 4:07 AM
> To: devel@edk2.groups.io
> Cc: Justen, Jordan L ; Laszlo Ersek
> ; Ard Biesheuvel
> ; Kinney, Michael D ;
> Gao, Limin
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2198
SEV-ES guest AP boot support needs to transition from 64-bit long mode
into 16-bit real mode. This will require a 16-bit code segment descriptor.
Reserve one of the spare segment descriptors (0x28) for this purpose.
Cc: Jian J Wang
Cc: Hao
