atari_defconfig would be a good one to try, followed by multi_defconfig, or (for the brave) multi_defconfig modified to have all drivers built-in.
multi_defconfig throws a fit: ------------[ cut here ]------------ WARNING: at kernel/softirq.c:141 local_bh_enable+0x72/0x80() Modules linked in: Call Trace: [<0002f430>] warn_on_slowpath+0x44/0x60 [<0003316e>] local_bh_enable+0x72/0x80 [<00041ccc>] sysctl_repair_table+0x0/0x2c [<00041efc>] sysctl_check_bin_path+0x12/0x94 [<00041eea>] sysctl_check_bin_path+0x0/0x94 [<00041ccc>] sysctl_repair_table+0x0/0x2c [<00042046>] sysctl_check_table+0xc8/0x37e [<00041eea>] sysctl_check_bin_path+0x0/0x94 [<00041ccc>] sysctl_repair_table+0x0/0x2c [<00042074>] sysctl_check_table+0xf6/0x37e [<00041eea>] sysctl_check_bin_path+0x0/0x94 [<00041ccc>] sysctl_repair_table+0x0/0x2c [<00042074>] sysctl_check_table+0xf6/0x37e [<00056660>] kmemdup+0x28/0x36 [<00128d6c>] random32+0xa/0xe [<0003316e>] local_bh_enable+0x72/0x80 [<001c8ac8>] neigh_parms_alloc+0xaa/0xcc [<001f6b54>] inetdev_init+0x60/0xd8 [<001f7ef2>] inetdev_event+0x114/0x170 [<001c22e4>] register_netdevice_notifier+0x5e/0x14a [<001f93f0>] inet_register_protosw+0x0/0xb4 [<00334e3c>] devinet_init+0x2a/0x72 [<001f79ce>] inet_gifconf+0x0/0xb2 [<003344c8>] ip_rt_init+0xec/0x1e4 [<0033470a>] ip_init+0x6/0xe [<003350a2>] inet_init+0xe6/0x1aa [<00334fbc>] inet_init+0x0/0x1aa [<0031985a>] do_one_initcall+0x0/0x16a [<00319876>] do_one_initcall+0x1c/0x16a [<000a0f4c>] sysfs_create_file+0x3c/0x42 [<0016350a>] sysdev_class_create_file+0x12/0x16 [<00165f22>] cpu_states_init+0x20/0x38 [<003199de>] do_initcalls+0x1a/0x30 [<00334fbc>] inet_init+0x0/0x1aa [<000027e2>] kernel_thread+0x0/0x50 [<00319a0e>] do_basic_setup+0x1a/0x1c [<00319a42>] kernel_init+0x20/0x5e [<0000281e>] kernel_thread+0x3c/0x50 ---[ end trace 429b268a213317ba ]---(on ARAnyM, that is). There was a warning about initcall net_ns_init returning with interrupts disabled that didn't show up in the atari only case.
Real hardware tests still pending ... Michael