> /usr/src/obj.i386/tooldir.NetBSD-1.6ZC-i386/bin/i386--netbsdelf-gcc -O2 -Wall -Wmissing-prototypes -Wstrict-prototypes -Os -mcpu=i386 -ffreestanding   -Werror -I/usr/src/sys/arch/i386/stand/bootxx/bootxx_ufs/../../../../..//lib/libkern/arch/i386 -DBOOTXX -I /usr/src/sys/arch/i386/stand/bootxx/bootxx_ufs/../../lib -I /usr/src/sys/arch/i386/stand/bootxx/bootxx_ufs/obj.i386 -DBOOTXX_SECTORS=15 -DPRIMARY_LOAD_ADDRESS=0x600 -DSECONDARY_LOAD_ADDRESS=0x10000 -DX86_BOOT_MAGIC_1="('x' << 24 | 0x86b << 12 | 'm' << 4 | 1)" -DXXfs_open=ufs_open -DXXfs_close=ufs_close -DXXfs_read=ufs_read -DXXfs_stat=ufs_stat -DFS=ufs -nostdinc -D_STANDALONE -I/usr/src/sys/arch/i386/stand/bootxx/bootxx_ufs/../../../../../ -DLIBSA_SINGLE_FILESYSTEM=xxfs -DLIBSA_NO_TWIDDLE -DLIBSA_NO_FD_CHECKING -DLIBSA_NO_RAW_ACCESS -DLIBSA_NO_FS_WRITE -DLIBSA_NO_FS_SEEK -DLIBSA_USE_MEMCPY -DLIBSA_USE_MEMSET -DLIBSA_SINGLE_DEVICE=blkdev -DLIBKERN_OPTIMISE_SPACE -D"blkdevioctl(x,y,z)=EINVAL" -D"blkdevclose(f)=0" -D"devopen!
>  (f,n,fl)=(*(fl)=(void *)n,0)" -DLIBSA_NO_DISKLABEL_MSGS -nostdinc -isystem /usr/src/obj.i386/destdir.i386/usr/include    -nostdinc -isystem /usr/src/obj.i386/destdir.i386/usr/include -c /usr/src/sys/arch/i386/stand/bootxx/bootxx_ufs/../../../../..//lib/libkern/arc4random.c -o arc4random.o.tmp
> /usr/src/sys/lib/libkern/arc4random.c: In function `arc4_randrekey':
> /usr/src/sys/lib/libkern/arc4random.c:141: error: `mono_time' undeclared (first use in this function)
> /usr/src/sys/lib/libkern/arc4random.c:141: error: (Each undeclared identifier is reported only once
> /usr/src/sys/lib/libkern/arc4random.c:141: error: for each function it appears in.)
> /usr/src/sys/lib/libkern/arc4random.c: In function `arc4random':
> /usr/src/sys/lib/libkern/arc4random.c:198: error: `mono_time' undeclared (first use in this function)
> /usr/src/sys/lib/libkern/arc4random.c: In function `arc4randbytes':
> /usr/src/sys/lib/libkern/arc4random.c:218: error: `mono_time' undeclared (first use in this function)

	mono_time shoudld be in src/sys/sys/kernel.h.  check your kernel.h.
	(mine is revision 1.21)

itojun