trouble

MIPS处理器的bootloader,龙芯就是用的修改过的PMON2

	PMON - Troubleshooting
	Troubleshooting

This page contains some hints and tips about solving problems that
you might encounter when using PMON. Note that many of these
solutions apply as much to IMON as they do PMON.

I can't get my Interrupts to work

The first thing to check is whether your peripheral's interrupts are
reaching the CPU. You can do this very simply from the PMON command line.

This example is for the 2681 DUART that LSI uses on most of its eval
boards. The values shown here are for the BDMR4101 eval board.

PMON fill . .+100 0	-- fill memory with nops.
PMON m be000017 ff	-- enable the 2681's interrupt mask.
PMON m be000017	-- check the 2681's Interrupt status register.
be000017 09 .		-- looks good. TXA, TXB, and Timer ints are asserted.
PMON t			-- single step. This causes PMON to reread 
			-- the CAUSE register.
PMON r cause		-- read the CAUSE value.
C0_CAUSE: BD CE   IP   SW EXCODE
          0  0 000001 00   Bp	-- Good. Int0 is asserted.

2-port Download Hangs
	This is usually caused by a download record that contains a
	reference to an unimplemented address.  Check the .map file for
	strange addresses. You can also use rdfrec -n (or rdsrec -n) to check the addresses
	that appear in the download record file.

	If you are suspicious about your cables, try using PMON's
	tr command to check out the connection. For
	example,

	PMON tr
	% edown < file.rec
	-- one line of data should appear in the PMON console window
	press cntrl-F in the console window
	-- another line of data should appear in the PMON console window
	press cntrl-K in the console window to return to the PMON prompt

Single-port Download Hangs
	This is usually caused by either,