external/mambo: Error out if kernel is too large
external/mambo: Error out if kernel is too large

If you're trying to boot a gigantic kernel in mambo (which you can
reproduce by building a kernel with CONFIG_MODULES=n) you'll get
misleading errors like:

WARNING: 0: (0): [0:0]: Invalid/unsupported instr 0x00000000[INVALID]
WARNING: 0: (0):  PC(EA): 0x0000000030000010 PC(RA):0x0000000030000010 MSR: 0x9000000000000000 LR: 0x0000000000000000
WARNING: 0: (0):  numInstructions = 0
WARNING: 1: (1): [0:0]: Invalid/unsupported instr 0x00000000[INVALID]
WARNING: 1: (1):  PC(EA): 0x0000000000000E40 PC(RA):0x0000000000000E40 MSR: 0x9000000000000000 LR: 0x0000000000000000
WARNING: 1: (1):  numInstructions = 1
WARNING: 1: (1): Interrupt to 0x0000000000000E40 from 0x0000000000000E40
INFO: 1: (2): ** Execution stopped: Continuous Interrupt, Instruction caused exception,  **

So add an error to skiboot.tcl to warn the user before this happens.
Making PAYLOAD_ADDR further back is one way to do this but if there's a
less gross way to generally work around this very niche problem, I can
suggest that instead.

Signed-off-by: Russell Currey <b5ebcef270cdc73fa0593440445c07a93ae1bccb@russell.cc>
Acked-by: Michael Neuling <7b0ab45a730e48a69239010b5b8fe5fa4e8eaac6@neuling.org>
Signed-off-by: Stewart Smith <ec31ab75ddf977353c8f660f92ea8b23f64aef25@linux.ibm.com>

shenki/skiboot,stewart-ibm/skiboot,qemu/skiboot,open-power/skiboot,qemu/skiboot,shenki/skiboot,open-power/skiboot,qemu/skiboot,stewart-ibm/skiboot,open-power/skiboot,legoater/skiboot,shenki/skiboot,legoater/skiboot,shenki/skiboot,legoater/skiboot,shenki/skiboot,legoater/skiboot,open-power/skiboot,stewart-ibm/skiboot,qemu/skiboot,qemu/skiboot,legoater/skiboot,open-power/skiboot