Re: [Qemu-devel] [PATCH] linuxboot_dma: compile for i486

[Richard W.M. Jones]

On Wed, May 31, 2017 at 02:44:18PM +0200, Paolo Bonzini wrote:
> The ROM uses the cmovne instruction, which is new in Pentium Pro and does not
> work when running QEMU with "-cpu 486".  Avoid producing that instruction.
> 
> Suggested-by: Richard W.M. Jones <address@hidden>
> Suggested-by: Thomas Huth <address@hidden>
> Reported-by: Rob Landley <address@hidden>
> Cc: address@hidden
> Signed-off-by: Paolo Bonzini <address@hidden>

I tested this using the reporter's test image
(http://landley.net/aboriginal/downloads/binaries/system-image-i486.tar.gz)
and it fixes the problem over here.

ACK.

Rich.

>  pc-bios/linuxboot_dma.bin  | Bin 1536 -> 1536 bytes
>  pc-bios/optionrom/Makefile |   1 +
>  2 files changed, 1 insertion(+)
> 
> diff --git a/pc-bios/linuxboot_dma.bin b/pc-bios/linuxboot_dma.bin
> index 
> 218d3ab4a29bfb5ab7125ec7a4d29dad1860c673..d176f62797813e4b926dca9dfce7ce554dc1a4d6
>  100644
> GIT binary patch
> literal 1536
> zcmeHFL2J`s82-{_T52KL%w~}udiW-YBE*9t=s~ClrIm^s9^6H6Pf%onr07*+kWd=L
> zpW)d<4G1ZESU1FyUDSCf^YYaxioy<}t?!rmu^#*f?mHxJo;-Qp_kHp#Je^o$|2##;
> zYs)n)qh6k7XI07O)9TW>>address@hidden@+rpuZy7{g_FpG^eo
> zuoD<address@hidden>a?#S!%6CsARNbiO)address@hidden
> ze8y7!akTy&address@hidden)Mtxe(3DE2)a5;c%$H0|Yu~mbnR0C7dKHR7Zsr
> zmrccq5lm%U=wXc39<t?-(_m*ZnY&YH(d(0lj;0`jj8e`iWgX(jV5j3gg<B9Cgj2^d
> zw;address@hidden<ui*Zsgx!lc)pgIq-atzea+i1H+3Oj<V?5-VpBVlz4R#!?
> zV3N_sX!mjsj*#|9H8ozR&D5ajsurT@(W<h&xG*;8UNvYI;address@hidden;AnvgFCdyy
> zI>address@hidden<bD(|L-BW|R)`qY*CS(3SQRXOVJqcpcuB8NLnUuosH3
> zi{OJ7mufeeG{^49xY<M4U)CrSC7Fp}TjtSE>UkNnpxu8npp2ruY0}SsKn=BiGN9Y;
> L*>&K*abWuoMsO(*
> 
> literal 1536
> zcmeHF&ubGw6rN4Dn#RCxYN|nUh%gpJFME=L9)#^}1F5!ps0f07iy|#(O1<iu!xFNH
> ze}?~naY4vZ57wZB1jMR`ST7r__~R&=_04QYJoq2jIn2&address@hidden|address@hidden<
> zD>address@hidden;?V$SuIwL6uYt5>dGyH&BPBIn1?(K>address@hidden
> address@hidden>Z7QOZy_v)9!Gc_A*CUnxyOgP~7<address@hidden
> z*1p4gW?~r|cz_FdqLT)y8y*s0Z-)z#_;!*cE?PD>cN4<HA{;MET(E~F0*Ke4l-T|Q
> zN3kAs(B4Nz%(_i>CX-n&AUsLGXj9UuS(2NP%(`OENoGw|EGqnf#7ASHq-k?KrExJ~
> z^CHnSr*VvZO%mMQmY+taei4m+{T$|c^(w4)XlpT*^|#=^eK`aF_0%gE_5j9w)aV=c
> zk7$UtO_Fkt>S!)address@hidden(na#Hj4<S)0RarUXZ%Tp{&xoU+SGxcuC<|i62e-
> zaCiw}LGfe}PpSO8%0DRczx~>MfwIDj65o<address@hidden(<_yF`A
> address@hidden;8HfA4iFwHr(rWNnH$vl3XJyEGJ>hT<|dXkK7E?qHJ9XdoKqMjysh
> address@hidden)N{RVuA8xQ~h
> 
> diff --git a/pc-bios/optionrom/Makefile b/pc-bios/optionrom/Makefile
> index fa53d9e58e..a9a9e5e7eb 100644
> --- a/pc-bios/optionrom/Makefile
> +++ b/pc-bios/optionrom/Makefile
> @@ -13,6 +13,7 @@ $(call set-vpath, $(SRC_PATH)/pc-bios/optionrom)
>  ifeq ($(lastword $(filter -O%, -O0 $(CFLAGS))),-O0)
>  override CFLAGS += -O2
>  endif
> +override CFLAGS += -march=i486
>  
>  # Drop -fstack-protector and the like
>  QEMU_CFLAGS := $(filter -W%, $(QEMU_CFLAGS)) $(CFLAGS_NOPIE) -ffreestanding
> -- 
> 2.13.0

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
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