Re: [Qemu-devel] Building qemu on UltraSparc

[Juergen Keil]

> Le dimanche 22 mai 2005 à 01:26 +0200, Herbert Poetzl a écrit :
> > On Sat, May 21, 2005 at 07:32:11PM +0200, Jérôme Warnier wrote:
> > > I'm trying to build qEmu v0.7.0 on Debian Sarge on a Sparc64 machine,
> > > and it fails with strange errors.
> > > Does anybody here have any idea to help me achieve it?
> > 
> > well, looks like you hit 32 vs 64 bit issues here, don't know
> > the details about the sparc/64 support but I'd try to build
> > as sparc32 first and see how far that gets ...
> I tried that (starting with utility sparc32), and it even fails faster.
> See the log attached.
> 
> > HTH,
> > Herbert
> 
> > > I attach the log of the build to this mail.
> > > 
> > > Thanks
> 
> Thanks for your help.
> 
> [..]


SPARC Host support is quite broken at this time, it seems.


> In file included from 
/home/jwarnier/debian/qemu-0.7.0/target-i386/op.c:724:/home/jwarnier/debian/qemu-0.7.0/targe
t-i386/ops_template.h: In function `op_jb_subb':
> /home/jwarnier/debian/qemu-0.7.0/target-i386/ops_template.h:278: warning: 
> implicit 
declaration of function `GOTO_LABEL_PARAM'


Yep, the macro GOTO_LABEL_PARAM is not defined for the sparc platform.

This needs to be fixed in dyngen-exec.h, with something like this:

Index: dyngen-exec.h
===================================================================
RCS file: /cvsroot/qemu/qemu/dyngen-exec.h,v
retrieving revision 1.25
diff -u -B -b -u -6 -r1.25 dyngen-exec.h
--- dyngen-exec.h       24 Apr 2005 18:01:56 -0000      1.25
+++ dyngen-exec.h       23 May 2005 08:04:45 -0000
@@ -225,14 +246,14 @@
 #ifdef __ia64__
 #define EXIT_TB() asm volatile ("br.ret.sptk.many b0;;")
 #define GOTO_LABEL_PARAM(n) asm volatile ("br.sptk.many " \
                                          ASM_NAME(__op_gen_label) #n)
 #endif
 #ifdef __sparc__
-#define EXIT_TB() asm volatile ("jmpl %i0 + 8, %g0\n" \
-                                "nop")
+#define EXIT_TB() asm volatile ("jmpl %i0 + 8, %g0; nop")
+#define        GOTO_LABEL_PARAM(n) asm volatile ("ba " 
ASM_NAME(__op_gen_label) #n ";nop")
 #endif
 #ifdef __arm__
 #define EXIT_TB() asm volatile ("b exec_loop")
 #define GOTO_LABEL_PARAM(n) asm volatile ("b " ASM_NAME(__op_gen_label) #n)
 #endif
 #ifdef __mc68000


The new "ba" instruction also requires a new type of relocation support for
R_SPARC_WDISP22 relocations in dyngen:

Index: dyngen.c
===================================================================
RCS file: /cvsroot/qemu/qemu/dyngen.c,v
retrieving revision 1.40
diff -u -B -b -u -6 -r1.40 dyngen.c
--- dyngen.c    27 Apr 2005 19:55:58 -0000      1.40
+++ dyngen.c    23 May 2005 08:04:45 -0000
@@ -2142,12 +2142,24 @@
                                    "    & 0x3fffffff);\n",
                                    rel->r_offset - start_offset,
                                    rel->r_offset - start_offset,
                                    name, addend,
                                    rel->r_offset - start_offset);
                            break;
+                       case R_SPARC_WDISP22:
+                           fprintf(outfile,
+                                   "    *(uint32_t *)(gen_code_ptr + %d) = "
+                                   "((*(uint32_t *)(gen_code_ptr + %d)) "
+                                   " & ~0x3fffff) "
+                                   " | ((((%s + %d) - (long)(gen_code_ptr + 
%d))>>2) "
+                                   "    & 0x3fffff);\n",
+                                   rel->r_offset - start_offset,
+                                   rel->r_offset - start_offset,
+                                   name, addend,
+                                   rel->r_offset - start_offset);
+                           break;
                         default:
                             error("unsupported sparc relocation (%d)", type);
                         }
                     }
                 }
             }


sparc64 probably needs a similar change to support WDISP22 relocations.



> ../dyngen -o op.h op.o
> dyngen: Found bogus save at the start of op_pavgb_mmx


That's another issue with sparc host support. x86 MMX instruction
support was added to qemu some time ago, and the compiler needs a *lot*
of register variables for the MMX opcode code templates.  Problem is
that on sparc a lot of cpu registers are already in use as "global
register" variables: most sparc global registers g1-g3, g6 and all local
registers l0-l7.  So the compiler starts to generate code that uses
frame pointer relative temporary variables in memory, because it's
running out of free cpu registers.  The use of temporary variables in
memory is incompatible with the way qemu's dyngen code generator works
on sparc.  That's basically what dyngen seems to be complaining about.



I've fixed this for now for Solaris SPARC host support, by reducing the
number of global cpu registers to just the global registers (g2-g6) -
freeing the local registers l0-l7.  With that change op_pavgb_mmx
doesn't need temporary variables in the local stack frame any more.

Index: dyngen-exec.h
===================================================================
RCS file: /cvsroot/qemu/qemu/dyngen-exec.h,v
retrieving revision 1.25
diff -u -B -b -u -6 -r1.25 dyngen-exec.h
--- dyngen-exec.h       24 Apr 2005 18:01:56 -0000      1.25
+++ dyngen-exec.h       23 May 2005 08:04:45 -0000
@@ -106,24 +119,32 @@
 #define AREG0 "s3"
 #define AREG1 "s0"
 #define AREG2 "s1"
 #define AREG3 "s2"
 #endif
 #ifdef __sparc__
+#ifdef _SOLARIS
+#define AREG0 "g2"
+#define AREG1 "g3"
+#define AREG2 "g4"
+#define AREG3 "g5"
+#define AREG4 "g6"
+#else
 #define AREG0 "g6"
 #define AREG1 "g1"
 #define AREG2 "g2"
 #define AREG3 "g3"
 #define AREG4 "l0"
 #define AREG5 "l1"
 #define AREG6 "l2"
 #define AREG7 "l3"
 #define AREG8 "l4"
 #define AREG9 "l5"
 #define AREG10 "l6"
 #define AREG11 "l7"
+#endif
 #define USE_FP_CONVERT
 #endif
 #ifdef __s390__
 #define AREG0 "r10"
 #define AREG1 "r7"
 #define AREG2 "r8"
Index: Makefile.target
===================================================================
RCS file: /cvsroot/qemu/qemu/Makefile.target,v
retrieving revision 1.69
diff -u -B -b -u -6 -r1.69 Makefile.target
--- Makefile.target     28 Apr 2005 21:15:08 -0000      1.69
+++ Makefile.target     23 May 2005 08:04:44 -0000
@@ -157,19 +157,25 @@
 ifeq ($(ARCH),s390)
 OP_CFLAGS=$(CFLAGS)
 LDFLAGS+=-Wl,-T,$(SRC_PATH)/s390.ld
 endif

 ifeq ($(ARCH),sparc)
+ifeq ($(CONFIG_SOLARIS),yes)
+CFLAGS+=-m32 -ffixed-g2 -ffixed-g3
+LDFLAGS+=-m32
+OP_CFLAGS=$(CFLAGS) -fno-delayed-branch -fno-omit-frame-pointer -ffixed-i0
+else
 CFLAGS+=-m32 -ffixed-g1 -ffixed-g2 -ffixed-g3 -ffixed-g6
 LDFLAGS+=-m32
 OP_CFLAGS=$(CFLAGS) -fno-delayed-branch -ffixed-i0
 HELPER_CFLAGS=$(CFLAGS) -ffixed-i0 -mflat
 # -static is used to avoid g1/g3 usage by the dynamic linker
 LDFLAGS+=-Wl,-T,$(SRC_PATH)/sparc.ld -static
 endif
+endif

 ifeq ($(ARCH),sparc64)
 CFLAGS+=-m64 -ffixed-g1 -ffixed-g2 -ffixed-g3 -ffixed-g6
 LDFLAGS+=-m64
 OP_CFLAGS=$(CFLAGS) -fno-delayed-branch -ffixed-i0
 endif


All of the above changes are part of bigger Solaris x86 / Solaris SPARC
/ FreeBSD / NetBSD patch that I'll attach below.


This patch won't immediately fix the issues that you've got on
linux/sparc, but it should give you some ideas where to start fixing
the build issues.

--
Juergen Keil                    address@hidden
Tools GmbH                      +49 (228) 9858011

qemu-solaris-freebsd-netbsd-patch.gz
Description: qemu-solaris-freebsd-netbsd-patch.gz