		Making ROMS
		Making ROMS

To make a ROM, first download the appropriate file 
to your PROM Programmer. The following table shows the location of the
various binaries.

Prom Monitor (PMON)

pmon/bg/pmon.rec (Big endian)

pmon/lg/pmon.rec (Little endian)

SerialICE Monitor (IMON)

imon/bg/imon.rec (Big endian)

imon/lg/imon.rec (Little endian)

SerialICE Kernels

bsps/k*.rec

Note that you will need to set the device type and split multiple (if
any) before you start the download. A split multiple is necessary if
the Target board requires more than one ROM
as a minimum configuration. 

Note that if your board requires more than one ROM as a minimum
configuration and is also using the little endian byte ordering, the ROMs will need to be
inserted in the reverse order to that used by a big endian processor.
For example, if a board has sockets A, and B, and for big endian,
device 1 from the programmer is inserted in socket A, and device 2 in
socket 2. The reverse will be true for little endian, ie. device 1 will
be inserted in socket B, and device 2 in socket A.

Then set the Programmer's record type to Motorola
S-records. For some toolsets, you will also need to specify an
offset on the PROM programmer. The offset is required because some
toolsets produce S-records that start at a non-zero address, whereas
most PROM programmers expect the S-records to start at zero.  The
following table shows the offsets required for the various MIPS
toolsets.

Offset

Toolset Vendor Name

ATMizer-1

ATMizer-2

Other MIPS CPUs

MIPS

0x00000000

0x00000000

0x00000000

EPI

0xa0c00000

0x80000000

0x9fc00000

BSO Tasking

0xa0c00000

0x80000000

0x9fc00000

Cygnus Support (ECOFF)

0x00000000

0x00000000

0x00000000

Cygnus Support (ELF)

0xa0c00000

0x80000000

0x9fc00000

Algorithmics

0x00000000

0x00000000

0x00000000

You must make sure that the PROM you are using is large enough to 
hold the program. Unfortunately, most PROM Programmers will not warn 
you if your program is too large. You should be suspicious if the PROM 
Programmer reports that the number of bytes downloaded is exactly the 
same size as your PROM; this generally means that some data is being 
omitted. Note that you cannot simply look at the address in the last 
record of the S-record file, because some toolsets do not emit the 
S-records in order.

If you don't have a PROM programmer, I can personally recommend the
emp20 programmer from
Needham's Electronics.
It is inexpensive and connects to the parallel port on a PC.


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