From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=37362 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1PHjt7-0007Ck-R3 for qemu-devel@nongnu.org; Sun, 14 Nov 2010 16:13:26 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1PHjt6-0007zq-Pj for qemu-devel@nongnu.org; Sun, 14 Nov 2010 16:13:25 -0500 Received: from mail-qw0-f45.google.com ([209.85.216.45]:33627) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1PHjt6-0007zk-LF for qemu-devel@nongnu.org; Sun, 14 Nov 2010 16:13:24 -0500 Received: by qwj8 with SMTP id 8so4652qwj.4 for ; Sun, 14 Nov 2010 13:13:24 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <20101114205432.GB14828@redhat.com> References: <1289749181-12070-1-git-send-email-gleb@redhat.com> <1289749181-12070-16-git-send-email-gleb@redhat.com> <20101114205432.GB14828@redhat.com> From: Blue Swirl Date: Sun, 14 Nov 2010 21:13:03 +0000 Message-ID: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Subject: [Qemu-devel] Re: [PATCHv4 15/15] Pass boot device list to firmware. List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Michael S. Tsirkin" Cc: kvm@vger.kernel.org, Gleb Natapov , armbru@redhat.com, qemu-devel@nongnu.org, alex.williamson@redhat.com, kevin@koconnor.net On Sun, Nov 14, 2010 at 8:54 PM, Michael S. Tsirkin wrote: > On Sun, Nov 14, 2010 at 08:49:59PM +0000, Blue Swirl wrote: >> On Sun, Nov 14, 2010 at 3:39 PM, Gleb Natapov wrote: >> > >> > Signed-off-by: Gleb Natapov >> > --- >> > =C2=A0hw/fw_cfg.c | =C2=A0 14 ++++++++++++++ >> > =C2=A0hw/fw_cfg.h | =C2=A0 =C2=A04 +++- >> > =C2=A0sysemu.h =C2=A0 =C2=A0| =C2=A0 =C2=A01 + >> > =C2=A0vl.c =C2=A0 =C2=A0 =C2=A0 =C2=A0| =C2=A0 51 ++++++++++++++++++++= +++++++++++++++++++++++++++++++ >> > =C2=A04 files changed, 69 insertions(+), 1 deletions(-) >> > >> > diff --git a/hw/fw_cfg.c b/hw/fw_cfg.c >> > index 7b9434f..f6a67db 100644 >> > --- a/hw/fw_cfg.c >> > +++ b/hw/fw_cfg.c >> > @@ -53,6 +53,7 @@ struct FWCfgState { >> > =C2=A0 =C2=A0 FWCfgFiles *files; >> > =C2=A0 =C2=A0 uint16_t cur_entry; >> > =C2=A0 =C2=A0 uint32_t cur_offset; >> > + =C2=A0 =C2=A0Notifier machine_ready; >> > =C2=A0}; >> > >> > =C2=A0static void fw_cfg_write(FWCfgState *s, uint8_t value) >> > @@ -315,6 +316,15 @@ int fw_cfg_add_file(FWCfgState *s, =C2=A0const ch= ar *filename, uint8_t *data, >> > =C2=A0 =C2=A0 return 1; >> > =C2=A0} >> > >> > +static void fw_cfg_machine_ready(struct Notifier* n) >> > +{ >> > + =C2=A0 =C2=A0uint32_t len; >> > + =C2=A0 =C2=A0char *bootindex =3D get_boot_devices_list(&len); >> > + >> > + =C2=A0 =C2=A0fw_cfg_add_bytes(container_of(n, FWCfgState, machine_re= ady), >> > + =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2= =A0 FW_CFG_BOOTINDEX, (uint8_t*)bootindex, len); >> >> I started to implement this to OpenBIOS but I noticed a small issue. >> First the first byte must be read to determine length. Then the read >> routine will be called again to read the correct amount of bytes. This >> would work, but since there is no shortage of IDs, I'd prefer a system >> where one ID is used to query the length and another ID is used to >> read the data, without the length byte. This is similar how command >> line, initrd etc. are handled. >> >> This would have the advantage that since fw_cfg uses little endian >> format, the length value would easily scale to for example 64 bits to >> support terabytes of boot device lists. ;-) > > Yea. Let's just print # of devices as a property, in ASCII. > No endian-ness, no nothing. > Also - can we just NULL-terminate each ID? No, we should use LE numbers like other IDs. To be more specific, this is what I meant (instead of FW_CFG_BOOTINDEX): FW_CFG_BOOTINDEX_LEN: get LE integer length of the boot device data. FW_CFG_BOOTINDEX_DATA: get the boot device data as NUL terminated C strings, all strings back-to-back. The reader can determine number of strings.