converting 10.3-i386 to 10.3-amd64

[Robert Huff]

    I have a machine, whose cpu is an AMD Phenom II, on which I
recently installed 10.3.  Spectifically:

FreeBSD 10.3-RELEASE #0 r297264: Fri Mar 25 03:51:29 UTC 2016
root at releng1.nyi.freebsd.org:/usr/obj/usr/src/sys/GENERIC  i386

    (Question: I thought the installation process was supposed to
detect the architecture and automatically install the correct
kernel+world.  Am I mistaken?)
    I want to convert this to:

FreeBSD 10.3-RELEASE #0 r297264: Fri Mar 25 03:51:29 UTC 2016
root at releng1.nyi.freebsd.org:/usr/obj/usr/src/sys/GENERIC  amd64

    in the short term to access all 8 gb of memory, and in the long
term to jump to -head.
    I have not changed /usr/src.
    There are no "make.conf" or "src.conf".
    Running "make buildworld" produces this:

cd /usr/src; PATH=/sbin:/bin:/usr/sbin:/usr/bin make -m
/usr/src/share/mk -f Makefile.inc1 TARGET=i386 TARGET_ARCH=i386 buildworld

    and "make buildkernel KERNCONF=GENERIC" this:

--------------------------------------------------------------
>>> stage 1: configuring the kernel
--------------------------------------------------------------
cd /usr/src/sys/i386/conf; 
PATH=/usr/obj/usr/src/tmp/legacy/usr/sbin:/usr/obj/usr/src/tmp/legacy/usr/bin:/usr/obj/usr/src/tmp/legacy/usr/games:/usr/obj/usr/src/tmp/legacy/bin:/usr/obj/usr/src/tmp/usr/sbin:/usr/obj/usr/src/tmp/usr/bin:/usr/obj/usr/src/tmp/usr/games:/sbin:/bin:/usr/sbin:/usr/bin 
config  -d /usr/obj/usr/src/sys/GENERIC  -I '/usr/src/sys/i386/conf'
'/usr/src/sys/i386/conf/GENERIC'
Kernel build directory is /usr/obj/usr/src/sys/GENERIC
Don't forget to do ``make cleandepend && make depend''

--------------------------------------------------------------
>>> stage 2.1: cleaning up the object tree
--------------------------------------------------------------
cd /usr/obj/usr/src/sys/GENERIC; MAKEOBJDIRPREFIX=/usr/obj 
MACHINE_ARCH=i386  MACHINE=i386  CPUTYPE=
GROFF_BIN_PATH=/usr/obj/usr/src/tmp/legacy/usr/bin 
GROFF_FONT_PATH=/usr/obj/usr/src/tmp/legacy/usr/share/groff_font 
GROFF_TMAC_PATH=/usr/obj/usr/src/tmp/legacy/usr/share/tmac 
_SHLIBDIRPREFIX=/usr/obj/usr/src/tmp  _LDSCRIPTROOT=  VERSION="FreeBSD
10.3-RELEASE i386 1003000"  INSTALL="sh /usr/src/tools/install.sh" 
PATH=/usr/obj/usr/src/tmp/legacy/usr/sbin:/usr/obj/usr/src/tmp/legacy/usr/bin:/usr/obj/usr/src/tmp/legacy/usr/games:/usr/obj/usr/src/tmp/legacy/bin:/usr/obj/usr/src/tmp/usr/sbin:/usr/obj/usr/src/tmp/usr/bin:/usr/obj/usr/src/tmp/usr/games:/sbin:/bin:/usr/sbin:/usr/bin
CC="cc " CXX="c++ "  CPP="cpp "  AS="as" AR="ar" LD="ld" NM=nm 
OBJDUMP=objdump OBJCOPY="objcopy"  RANLIB=ranlib STRINGS=
COMPILER_TYPE=clang make  -m /usr/src/share/mk  KERNEL=kernel cleandir
rm -f *.o *.so *.So *.ko *.s eddep errs  kernel.debug kernel
kernel.symbols  linterrs tags vers.c  vnode_if.c vnode_if.h
vnode_if_newproto.h vnode_if_typedef.h  agp_if.c ata_if.c eisa_if.c
fb_if.c miibus_if.c mmcbr_if.c mmcbus_if.c mvs_if.c card_if.c power_if.c
pci_if.c pcib_if.c ppbus_if.c sdhci_if.c hdac_if.c ac97_if.c
channel_if.c feeder_if.c mixer_if.c mpu_if.c mpufoi_if.c synth_if.c
uart_if.c usb_if.c g_part_if.c g_raid_md_if.c g_raid_tr_if.c isa_if.c
bus_if.c clock_if.c cpufreq_if.c device_if.c linker_if.c serdev_if.c
xenbus_if.c xenbusb_if.c acpi_if.c acpi_wmi_if.c virtio_bus_if.c
virtio_if.c agp_if.h ata_if.h eisa_if.h fb_if.h miibus_if.h mmcbr_if.h
mmcbus_if.h mvs_if.h card_if.h power_if.h pci_if.h pcib_if.h ppbus_if.h
sdhci_if.h hdac_if.h ac97_if.h channel_if.h feeder_if.h mixer_if.h
mpu_if.h mpufoi_if.h synth_if.h uart_if.h usb_if.h g_part_if.h
g_raid_md_if.h g_raid_tr_if.h isa_if.h bus_if.h clock_if.h cpufreq_if.h
device_if.h linker_if.h serdev_if.h xenbus_if.h xenbusb_if.h acpi_if.h
acpi_wmi_if.h virtio_bus_if.h virtio_if.h  acpi_quirks.h feeder_eq_gen.h
feeder_rate_gen.h snd_fxdiv_gen.h  miidevs.h pccarddevs.h teken_state.h
usbdevs.h usbdevs_data.h  acpi_wakecode.o acpi_wakecode.bin
acpi_wakecode.h  acpi_wakedata.h

    which says it's compiling for i386.
    How do I compel it to use src/sys/amd64 instead of
src/sys/i386?


            Respectfully,


                    Robert Huff