Patchwork RE: Qemu-devel Digest, Vol 82, Issue 324

login
register
mail settings
Submitter Yasin Yenidünya
Date Jan. 29, 2010, 9:22 p.m.
Message ID <002401caa129$1baf8820$530e9860$@com>
Download mbox | patch
Permalink /patch/44035/
State New
Headers show

Comments

Yasin Yenidünya - Jan. 29, 2010, 9:22 p.m.
Hello,

I want to develop an linux os. Does anyone has a tutorial to build an
operting system? Or if some one has the soruce code of linux that comes with
qemu it is also enought for me..

Regards


-----Original Message-----
From: qemu-devel-bounces+machka=gmail.com@nongnu.org
[mailto:qemu-devel-bounces+machka=gmail.com@nongnu.org] On Behalf Of
qemu-devel-request@nongnu.org
Sent: Friday, January 29, 2010 10:44 PM
To: qemu-devel@nongnu.org
Subject: Qemu-devel Digest, Vol 82, Issue 324

Send Qemu-devel mailing list submissions to
	qemu-devel@nongnu.org

To subscribe or unsubscribe via the World Wide Web, visit
	http://lists.nongnu.org/mailman/listinfo/qemu-devel
or, via email, send a message with subject or body 'help' to
	qemu-devel-request@nongnu.org

You can reach the person managing the list at
	qemu-devel-owner@nongnu.org

When replying, please edit your Subject line so it is more specific
than "Re: Contents of Qemu-devel digest..."


Today's Topics:

   1. [PATCH 5/5] virtio-blk: add topology support (Christoph Hellwig)
   2. Re: [PATCH] Porting TCG to alpha platform (Richard Henderson)
   3. [PATCH] doc: Update mingw cross compile instructions (Scott Tsai)
   4. [RFC] wiki.qemu.org (Anthony Liguori)
   5. Re: [RFC] wiki.qemu.org (Scott Tsai)
   6. Re: [RFC] wiki.qemu.org (Andreas F?rber)
   7. Re: [PATCH 1/3] virtio_blk: Factor	virtio_blk_handle_request
      out (Anthony Liguori)


----------------------------------------------------------------------

Message: 1
Date: Fri, 29 Jan 2010 20:05:31 +0100
From: Christoph Hellwig <hch@lst.de>
Subject: [Qemu-devel] [PATCH 5/5] virtio-blk: add topology support
To: qemu-devel@nongnu.org
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Message-ID: <20100129190531.GD25287@lst.de>
Content-Type: text/plain; charset=us-ascii

Export all topology information in the block config structure,
guarded by a new VIRTIO_BLK_F_TOPOLOGY config flag.

Note that there is no savevm support for the new information yet,
as it would be a pain without the table driven savevm format.
Juan has promised to send out a new version of the table driven
vmstate patches for virto next week.

Signed-off-by: Christoph Hellwig <hch@lst.de>

 
-Note: Currently, Wine does not seem able to launch
-QEMU for Win32.
+Wine can be used to launch the resulting qemu.exe compiled for Win32.
 
 @node Mac OS X
 @section Mac OS X
Mulyadi Santosa - Jan. 31, 2010, 8:48 a.m.
2010/1/30 Yasin Yenidünya <machka@gmail.com>:
> Hello,
>
> I want to develop an linux os. Does anyone has a tutorial to build an
> operting system? Or if some one has the soruce code of linux that comes with
> qemu it is also enought for me..

You wanna develop from scratch? or extend the existing one like Linux kernel?

Anyway, maybe you'll find this URL interesting: www.kernelnewbies.org

Patch

Index: qemu/hw/virtio-blk.c
===================================================================
--- qemu.orig/hw/virtio-blk.c	2010-01-29 19:42:11.853022001 +0100
+++ qemu/hw/virtio-blk.c	2010-01-29 19:45:14.735253918 +0100
@@ -380,6 +380,10 @@  static void virtio_blk_update_config(Vir
     blkcfg.heads = heads;
     blkcfg.sectors = secs;
     blkcfg.size_max = 0;
+    blkcfg.physical_block_exp = bdrv_get_physical_block_exp(s->bs);
+    blkcfg.alignment_offset = 0;
+    blkcfg.min_io_size = bdrv_get_min_io_size(s->bs);
+    blkcfg.opt_io_size = bdrv_get_opt_io_size(s->bs);
     memcpy(config, &blkcfg, sizeof(struct virtio_blk_config));
 }
 
@@ -389,6 +393,7 @@  static uint32_t virtio_blk_get_features(
 
     features |= (1 << VIRTIO_BLK_F_SEG_MAX);
     features |= (1 << VIRTIO_BLK_F_GEOMETRY);
+    features |= (1 << VIRTIO_BLK_F_TOPOLOGY);
 
     if (bdrv_enable_write_cache(s->bs))
         features |= (1 << VIRTIO_BLK_F_WCACHE);
Index: qemu/hw/virtio-blk.h
===================================================================
--- qemu.orig/hw/virtio-blk.h	2010-01-29 19:45:17.996022961 +0100
+++ qemu/hw/virtio-blk.h	2010-01-29 19:45:39.253318328 +0100
@@ -32,6 +32,7 @@ 
 #define VIRTIO_BLK_F_SCSI       7       /* Supports scsi command passthru
*/
 /* #define VIRTIO_BLK_F_IDENTIFY   8       ATA IDENTIFY supported,
DEPRECATED */
 #define VIRTIO_BLK_F_WCACHE     9       /* write cache enabled */
+#define VIRTIO_BLK_F_TOPOLOGY   10      /* Topology information is
available */
 
 struct virtio_blk_config
 {
@@ -42,6 +43,10 @@  struct virtio_blk_config
     uint8_t heads;
     uint8_t sectors;
     uint32_t _blk_size;    /* structure pad, currently unused */
+    uint8_t physical_block_exp;
+    uint8_t alignment_offset;
+    uint16_t min_io_size;
+    uint32_t opt_io_size;
 } __attribute__((packed));
 
 /* These two define direction. */




------------------------------

Message: 2
Date: Fri, 29 Jan 2010 11:19:20 -0800
From: Richard Henderson <rth@twiddle.net>
Subject: Re: [Qemu-devel] [PATCH] Porting TCG to alpha platform
To: identifier scorpio <cidentifier@yahoo.com.cn>
Cc: qemu-devel@nongnu.org
Message-ID: <4B6334B8.9040002@twiddle.net>
Content-Type: text/plain; charset="utf-8"

> +        } else if (cond == TCG_COND_EQ || cond == TCG_COND_NE) {
> +            tcg_out_mem_long(s, INSN_LDA, TMP_REG1, arg1, -arg2);
> +            opc = (cond == TCG_COND_EQ ? INSN_BEQ : INSN_BNE);

Bug here.  What was intended was to add "arg1 = TMP_REG1".
But since the constraints use "I" for uint8_t input constants,
we might as well remove this hunk entirely.

Also, let's future-proof this routine against changes to
the layout of the TCGCond enumeration.


r~
-------------- next part --------------
commit 9d787576342c193f13e2531953fc81442458de7e
Author: Richard Henderson <rth@twiddle.net>
Date:   Fri Jan 29 11:14:20 2010 -0800

    tcg-alpha: Fix EQ/NE with a constant.
    
    There was start of code to handle EQ and NE with arbitrary constants,
    but it wasn't completed.  Remove the half-done code and add a comment
    for future enhancements.
    
    Also, don't rely on the current layout of TCGCond; instead encode the
    need for inversion of the compare insn result by means of a low bit set
    in the cmp_opc table.  Reduce the element size of cmp_opc.

diff --git a/tcg/alpha/tcg-target.c b/tcg/alpha/tcg-target.c
index 5b7dd25..18ab2c8 100644
--- a/tcg/alpha/tcg-target.c
+++ b/tcg/alpha/tcg-target.c
@@ -540,9 +540,11 @@  static void tcg_out_br(TCGContext *s, int opc, int ra,
int label_index)
     tcg_out_fmt_br(s, opc, ra, value);
 }
 
-static void tcg_out_brcond(TCGContext *s, int cond, TCGArg arg1,
+static void tcg_out_brcond(TCGContext *s, TCGCond cond, TCGArg arg1,
                            TCGArg arg2, int const_arg2, int label_index)
 {
+    /* Note that unsigned comparisons are not present here, which means
+       that their entries will contain zeros.  */
     static const int br_opc[10] = {
         [TCG_COND_EQ] = INSN_BEQ,
         [TCG_COND_NE] = INSN_BNE,
@@ -552,38 +554,56 @@  static void tcg_out_brcond(TCGContext *s, int cond,
TCGArg arg1,
         [TCG_COND_GT] = INSN_BGT
     };
 
-    static const uint64_t cmp_opc[10] = {
+    /* The low bit of these entries indicates that the result of 
+       the comparison must be inverted.  This bit should not be
+       output with the rest of the instruction.  */
+    static const int cmp_opc[10] = {
         [TCG_COND_EQ] = INSN_CMPEQ,
-        [TCG_COND_NE] = INSN_CMPEQ,
+        [TCG_COND_NE] = INSN_CMPEQ | 1,
         [TCG_COND_LT] = INSN_CMPLT,
-        [TCG_COND_GE] = INSN_CMPLT,
+        [TCG_COND_GE] = INSN_CMPLT | 1,
         [TCG_COND_LE] = INSN_CMPLE,
-        [TCG_COND_GT] = INSN_CMPLE,
+        [TCG_COND_GT] = INSN_CMPLE | 1,
         [TCG_COND_LTU] = INSN_CMPULT,
-        [TCG_COND_GEU] = INSN_CMPULT,
+        [TCG_COND_GEU] = INSN_CMPULT | 1,
         [TCG_COND_LEU] = INSN_CMPULE,
-        [TCG_COND_GTU] = INSN_CMPULE
+        [TCG_COND_GTU] = INSN_CMPULE | 1
     };
 
     int opc = 0;
 
-    if (const_arg2) {
-        if (arg2 == 0) {
-            opc = br_opc[cond];
-        } else if (cond == TCG_COND_EQ || cond == TCG_COND_NE) {
-            tcg_out_mem_long(s, INSN_LDA, TMP_REG1, arg1, -arg2);
-            opc = (cond == TCG_COND_EQ ? INSN_BEQ : INSN_BNE);
-        }
+    /* Possible improvements:
+       (1) Notice arg1 == $31 and !const_arg2.  In this case, swap the
+       two operands and swap the sense of the comparison to allow the
+       use of the direct branches.
+
+       (2) Allow arbitrary constants.  We can, on occasion, generate one
+       less instruction if we compute
+           TMP = ARG1 - CONST
+       instead of
+           TMP = ARG1 cmp TMP2
+       where TMP2 is the constant loaded into a register by generic code.
+       Note that for 64-bit operands this works only for EQ and NE.  For
+       32-bit operands, we would need to either limit this to signed
+       comparisons or properly zero-extend unsigned inputs.  The payoff
+       here isn't great though; much less than(1).  */
+
+    /* Notice signed comparisons vs zero.  These are handled by the
+       branch instructions directly.  */
+    if (const_arg2 && arg2 == 0) {
+        opc = br_opc[cond];
     }
 
+    /* Otherwise, generate a comparison into a temporary.  */
     if (opc == 0) {
-        opc = cmp_opc[cond];
+        opc = cmp_opc[cond] & ~1;
         if (const_arg2) {
             tcg_out_fmt_opi(s, opc, arg1, arg2, TMP_REG1);
         } else {
             tcg_out_fmt_opr(s, opc, arg1, arg2, TMP_REG1);
         }
-        opc = (cond & 1) ? INSN_BEQ : INSN_BNE;
+
+        opc = (cmp_opc[cond] & 1 ? INSN_BEQ : INSN_BNE);
         arg1 = TMP_REG1;
     }
 

------------------------------

Message: 3
Date: Sat, 30 Jan 2010 03:28:58 +0800
From: Scott Tsai <scottt.tw@gmail.com>
Subject: [Qemu-devel] [PATCH] doc: Update mingw cross compile
	instructions
To: qemu-devel@nongnu.org
Cc: Scott Tsai <scottt.tw@gmail.com>
Message-ID: <1264793338-30981-1-git-send-email-scottt.tw@gmail.com>

The "Cross compilation for Windows with Linux" section of qemu-doc.texi
still instructs the user to use 'configure --enable-mingw32'
even after the option was removed in Aug 2008:
http://git.savannah.gnu.org/cgit/qemu.git/commit/?id=cd01b4a312248dd4e12c3d3
89d1a349cea4015d8

This documentation only change updates the instructions to:
* Remove use of '--enable-mingw32' in the configure example
* Correct the 'sdl-config' script name
* Remove references to i386-mingw32msvc.tar.gz which no longer exists in
  recent SDL releases
* Document the zlib dependency

Signed-off-by: Scott Tsai <scottt.tw@gmail.com>
---
 qemu-doc.texi |   45 +++++++++++++++++++++++++++++++--------------
 1 files changed, 31 insertions(+), 14 deletions(-)

diff --git a/qemu-doc.texi b/qemu-doc.texi
index 2fb5c0b..4e220d0 100644
--- a/qemu-doc.texi
+++ b/qemu-doc.texi
@@ -2313,11 +2313,14 @@  instructions in the download section and the FAQ.
 @item Download
 the MinGW development library of SDL 1.2.x
 (@file{SDL-devel-1.2.x-@/mingw32.tar.gz}) from
-@url{http://www.libsdl.org}. Unpack it in a temporary place, and
-unpack the archive @file{i386-mingw32msvc.tar.gz} in the MinGW tool
-directory. Edit the @file{sdl-config} script so that it gives the
+@url{http://www.libsdl.org}. Unpack it in a temporary place and
+edit the @file{sdl-config} script so that it gives the
 correct SDL directory when invoked.
 
+@item Install the MinGW version of zlib and make sure
+@file{zlib.h} and @file{libz.dll.a} are in
+MingGW's default header and linker search paths.
+
 @item Extract the current version of QEMU.
 
 @item Start the MSYS shell (file @file{msys.bat}).
@@ -2340,29 +2343,43 @@  correct SDL directory when invoked.
 Install the MinGW cross compilation tools available at
 @url{http://www.mingw.org/}.
 
-@item
-Install the Win32 version of SDL (@url{http://www.libsdl.org}) by
-unpacking @file{i386-mingw32msvc.tar.gz}. Set up the PATH environment
-variable so that @file{i386-mingw32msvc-sdl-config} can be launched by
+@item Download
+the MinGW development library of SDL 1.2.x
+(@file{SDL-devel-1.2.x-@/mingw32.tar.gz}) from
+@url{http://www.libsdl.org}. Unpack it in a temporary place and
+edit the @file{sdl-config} script so that it gives the
+correct SDL directory when invoked.  Set up the @code{PATH} environment
+variable so that @file{sdl-config} can be launched by
 the QEMU configuration script.
 
+@item Install the MinGW version of zlib and make sure
+@file{zlib.h} and @file{libz.dll.a} are in
+MingGW's default header and linker search paths.
+
 @item
 Configure QEMU for Windows cross compilation:
 @example
-./configure --enable-mingw32
+PATH=/usr/i686-pc-mingw32/sys-root/mingw/bin:$PATH ./configure
--cross-prefix='i686-pc-mingw32-'
+@end example
+The example assumes @file{sdl-config} is installed under
@file{/usr/i686-pc-mingw32/sys-root/mingw/bin} and
+MinGW cross compilation tools have names like @file{i686-pc-mingw32-gcc}
and @file{i686-pc-mingw32-strip}.
+We set the @code{PATH} environment variable to ensure the MingW version of
@file{sdl-config} is used and
+use --cross-prefix to specify the name of the cross compiler.
+You can also use --prefix to set the Win32 install path which defaults to
@file{c:/Program Files/Qemu}.
+
+Under Fedora Linux, you can run:
+@example
+yum -y install mingw32-gcc mingw32-SDL mingw32-zlib
 @end example
-If necessary, you can change the cross-prefix according to the prefix
-chosen for the MinGW tools with --cross-prefix. You can also use
---prefix to set the Win32 install path.
+to get a suitable cross compilation environment.
 
 @item You can install QEMU in the installation directory by typing
-@file{make install}. Don't forget to copy @file{SDL.dll} in the
+@code{make install}. Don't forget to copy @file{SDL.dll} and
@file{zlib1.dll} into the
 installation directory.
 
 @end itemize