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Date: Sun, 7 Jan 2024 20:47:16 +0100
From: Borislav Petkov <bp@alien8.de>
To: Aleksander Mazur <deweloper@wp.pl>
Cc: Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>,
	Dave Hansen <dave.hansen@linux.intel.com>, x86@kernel.org,
	linux-kernel@vger.kernel.org, "H. Peter Anvin" <hpa@zytor.com>
Subject: Re: [PATCH] x86/Kconfig: Transmeta Crusoe is cpu family 5, not 6
Message-ID: <20240107194716.GDZZr/xBl3+G8O7i7E@fat_crate.local>
References: <1517697968-19014-3-git-send-email-tedheadster@gmail.com>
 <20240107140609.2c1709e3@mocarz>
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On Sun, Jan 07, 2024 at 02:16:57PM +0100, Aleksander Mazur wrote:
> I found out I am no longer able to boot kernel compiled with CONFIG_MCRUSOE=y on
> my HP t5300 with CPU: Transmeta(tm) Crusoe(tm) Processor TM5500 (family: 0x5,
> model: 0x4, stepping: 0x3). It says:
> 
> > This kernel requires an i686 CPU, but only detected an i586 CPU.
> > Unable to boot - please use a kernel appropriate for your CPU.    
> 
> It looks like this is caused by 25d76ac888216c369dea91768764728b83769799 which
> started setting X86_MINIMUM_CPU_FAMILY=6 for MCRUSOE while CPUID gives family=5.
> 
> I was able to fix the problem with a patch included below. It just changes
> X86_MINIMUM_CPU_FAMILY to 5

... for MCRUSOE.

> No other change was necessary (using -march=i686
> seems fine).
> 
> /proc/cpuinfo:
> processor	: 0
> vendor_id	: GenuineTMx86
> cpu family	: 5
> model		: 4
> model name	: Transmeta(tm) Crusoe(tm) Processor TM5500
> stepping	: 3
> cpu MHz		: 532.091
> cache size	: 256 KB
> fdiv_bug	: no
> f00f_bug	: no
> coma_bug	: no
> fpu		: yes
> fpu_exception	: yes
> cpuid level	: 1
> wp		: yes
> flags		: fpu vme de pse tsc msr cx8 sep cmov mmx longrun lrti constant_tsc cpuid
> bugs		: cpu_meltdown spectre_v1 spectre_v2 spec_store_bypass l1tf mds swapgs itlb_multihit mmio_unknown
> bogomips	: 1064.18
> clflush size	: 32
> cache_alignment	: 32
> address sizes	: 32 bits physical, 32 bits virtual
> power management:
> 
> --- a/arch/x86/Kconfig.cpu
> +++ b/arch/x86/Kconfig.cpu
> @@ -375,7 +375,7 @@
>  config X86_MINIMUM_CPU_FAMILY
>  	int
>  	default "64" if X86_64
> -	default "6" if X86_32 && (MPENTIUM4 || MPENTIUMM || MPENTIUMIII || MPENTIUMII || M686 || MVIAC3_2 || MVIAC7 || MEFFICEON || MATOM || MCRUSOE || MCORE2 || MK7 || MK8)
> +	default "6" if X86_32 && (MPENTIUM4 || MPENTIUMM || MPENTIUMIII || MPENTIUMII || M686 || MVIAC3_2 || MVIAC7 || MEFFICEON || MATOM || MCORE2 || MK7 || MK8)
>  	default "5" if X86_32 && X86_CMPXCHG64
>  	default "4"

Care to turn this into a proper patch with your SOB etc?

Thx.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette