Gerd Hoffmann wrote:

> On Sun, Feb 28, 2021 at 02:22:53PM -0000, Yiguang Chen wrote:

> >   Most time, When a vm with seabios start. The bios will

> > display such info:

> >  -----

> >  Seabios (version rel-1.13-0 ......)

> >  Machine UUID ...

> >  

> >  IPXE ..

> >  

> >  IPXE..

> >  

> >  Booting from DVD/CD...

> >  Press any key to boot from CD or DVD.

> >  ---

> >  

> >  It means that have a bootable cdrom to boot. But If we want to boot

> >  from cdrom, we must press any key as what the warning had said. If it

> >  is possible to boot from DVD/CD automatically, instead of pressing a

> >  key by hand? 

> This is a windows install iso, right?

You are right. The cdrom is a windows install iso. 

> This isn't seabios, the windows boot loader does that.  I think windows

> does this only in case it finds a bootable hard disk.  So when booting

> the guest with a fresh & blank virtual hard disk it should boot the

> windows installer without asking for a key press.

It seems that the windows install iso cause this behavior and the seabios source code prove this.

--- roms/seabios/src/boot.c

static void

boot_cdrom(struct drive_s *drive)

{

    if (! CONFIG_CDROM_BOOT)

        return;

    printf("Booting from DVD/CD...\n");

    int status = cdrom_boot(drive);

    if (status) {

        printf("Boot failed: Could not read from CDROM (code %04x)\n", status);

        return;

    }

    u8 bootdrv = CDEmu.emulated_drive;

    u16 bootseg = CDEmu.load_segment;

    tpm_add_cdrom(bootdrv, MAKE_FLATPTR(bootseg, 0), 512);

    /* Canonicalize bootseg:bootip */

    u16 bootip = (bootseg & 0x0fff) << 4;

    bootseg &= 0xf000;

    call_boot_entry(SEGOFF(bootseg, bootip), bootdrv);

}

---

Best regards,

YiguangChen