[E3-hacking] Success!

David Given e3-hacking@earth.li
Wed, 16 Mar 2005 00:17:30 +0000


My line level converter works! Woohoo! (It turns out that it helps if
you look at the *right* diagram on the datasheet, make sure that you
correctly work out which wire of the cable is connected to which pin,
and generally don't do a bunch of really embarassing stuff. On the plus
side, it turns out that MAX232 chips are much more robust than I
thought.)

What's more, pblq has now turned into a reasonably generalised mechanism
for communicating with PBL, complete with the ability to suck down data
using one-byte checksum packets. Currently it's running at 9600 baud,
which means it maxes out at 16 bytes per second --- that's a bit over an
hour to download PBL, and six *days* for the main flash --- so I've only
downloaded fragments. Here's a log; do the checksums match your boards?

$ ./pblq 
Attempting handshake...
Connected.
PBL V3.1 build 1277
Maximum packet length is 8208
Checksum of 00000000+10000: 00A828D0
Checksum of 80010000+550000: 349F8B09
Downloadng: ################

$ objdump -D -b binary -m arm7tdmi output.img 

output.img:     file format binary

Disassembly of section .data:

0000000000000000 <.data>:
   0:   ea000054        b       0x158
   4:   ea000055        b       0x160
   8:   ea00005e        b       0x188
   c:   ea000054        b       0x164
  10:   ea000054        b       0x168
  14:   00000000        andeq   r0, r0, r0
  18:   ea001eb2        b       0x7ae8
  1c:   ea001e86        b       0x7a3c
  20:   00000000        andeq   r0, r0, r0
  24:   00007740        andeq   r7, r0, r0, asr #14
...etc...

I'll get it doing a bit more, polish the interface a bit --- in order to
change options, you have to recompile it, which isn't good --- and post
it somewhere in a couple of days, if people think it would be useful...

-- 
+- David Given --McQ-+ 
|  dg@cowlark.com    | "Home is where, when you have to go there, they
| (dg@tao-group.com) | have to take you in." --- Cordelia Naismith
+- www.cowlark.com --+