Re: [PATCH 04/15] ArmVirtPkg/PrePi: remove bogus primary core check

[Laszlo Ersek <lersek@redhat.com>]

On 11/17/17 17:09, Ard Biesheuvel wrote:
> QEMU and KVM based ARM/AARCH64 virtual machines only enter UEFI on
> a single core, so ArmPlatformIsPrimaryCore() always returns true.
> And even if it didn't, our code does absolutely nothing meaningful
> based on its return value, so don't bother calling it, and remove
> another frivolous dependency on ArmPlatformLib.
> 
> Contributed-under: TianoCore Contribution Agreement 1.1
> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> ---
>  ArmVirtPkg/PrePi/AArch64/ModuleEntryPoint.S | 7 -------
>  ArmVirtPkg/PrePi/Arm/ModuleEntryPoint.S     | 7 -------
>  2 files changed, 14 deletions(-)
> 
> diff --git a/ArmVirtPkg/PrePi/AArch64/ModuleEntryPoint.S b/ArmVirtPkg/PrePi/AArch64/ModuleEntryPoint.S
> index cc8b47e69026..7a9c0c3787cc 100644
> --- a/ArmVirtPkg/PrePi/AArch64/ModuleEntryPoint.S
> +++ b/ArmVirtPkg/PrePi/AArch64/ModuleEntryPoint.S
> @@ -128,13 +128,6 @@ _GetStackBase:
>    MOV32 (x3, FixedPcdGet32(PcdCPUCoreSecondaryStackSize))
>    bl    ASM_PFX(ArmPlatformStackSet)
>  
> -  // Is it the Primary Core ?
> -  mov   x0, x10
> -  bl    ASM_PFX(ArmPlatformIsPrimaryCore)
> -  cmp   x0, #1
> -  bne   _PrepareArguments
> -
> -_PrepareArguments:
>    mov   x0, x20
>    mov   x1, x21
>    mov   x2, x22
> diff --git a/ArmVirtPkg/PrePi/Arm/ModuleEntryPoint.S b/ArmVirtPkg/PrePi/Arm/ModuleEntryPoint.S
> index 59028d0a553e..eebf660acdb2 100644
> --- a/ArmVirtPkg/PrePi/Arm/ModuleEntryPoint.S
> +++ b/ArmVirtPkg/PrePi/Arm/ModuleEntryPoint.S
> @@ -136,13 +136,6 @@ _GetStackBase:
>    MOV32 (r3, FixedPcdGet32(PcdCPUCoreSecondaryStackSize))
>    bl    ASM_PFX(ArmPlatformStackSet)
>  
> -  // Is it the Primary Core ?
> -  mov   r0, r10
> -  bl    ASM_PFX(ArmPlatformIsPrimaryCore)
> -  cmp   r0, #1
> -  bne   _PrepareArguments
> -
> -_PrepareArguments:
>    mov   r0, r10
>    mov   r1, r11
>    mov   r2, r9
> 

I'll assume ArmPlatformIsPrimaryCore has no side effects. Beyond that,
even I can see that

  conditional-jump LABEL
LABEL: ...

is a no-op :)

Reviewed-by: Laszlo Ersek <lersek@redhat.com>