readme.txt

一款MP3 Player Firmware 的原代码,非常有参考价值

MP3 Player Firmware
-------------------

This is the source code for the MP3 Player project at:

     http://www.pjrc.com/tech/mp3/firmware.html



License
-------

There are four different sets of licensing terms for the
various files in this project.  All of the actual source
code is either GPL'd or public domain.  Data files which
are downloaded to ICs on the board have licensing terms
which generally limit their use to the intended hardware.


1) "pm2_mp3.asm" is in public domain.  Simple!  "paulmon2.asx"
and "paulmon2.h" are also in the public domain.

2) "nodram.mcs" is licensed under the "PJRC Hardware
Configuration Data License" (see "HCDL.TXT").  This data in
this file is effectively part of the player's hardware, and
may only be used with hardware purchased from PJRC.COM, LLC,
or with a non-commercial custom build hobbist project, as
specified in the license agreement.

3) "p02_0609.bin" is provided by ST Microelectronics, without
explicit licensing terms.  It is clearly intended to be used
with their STA013 chip.

4) all other files are covered by the GNU General Public
License (GPL), (see "GPL.TXT") with a specific exception that
the resulting executable code may be combined with the files
listed above.  A combined executable including "nodram.mcs"
may only be used with hardware manufactured by PJRC.COM, LLC,
or non-commercial custom built hobbist projects.



Build Instructions
------------------

To build this project, you will need the AS31 assembler,
available for free at:

http://www.pjrc.com/tech/8051/#as31_assembler

On a Linux system, unpack the AS31 source, build with
make, and copy "as31" to a directory in your path:

    tar -xvzf as31_beta3.tar.gz 
    cd as31
    make
    su  <enter root password at prompt>
    cp as31 /usr/local/bin


You will also need the SDCC C compiler, version 2.2.1,
which is available at:

http://sdcc.sourceforge.net/


  UPDATE: SDCC 2.2.1 will not work.  You will need a very
  recent CVS version.  Here is an archive of a version
  that is tested and known to work:

  http://inetarena.com/~pjrc/sdcc230_mp30634.tar.gz

  TODO: modify the commands below to reflect this version....



On Linux system, unpack the SDCC distribution, and
build with the usual configure, make, make install:

    tar -xvzf sdcc230_mp30634.tar.gz
    cd sdcc
    ./configure
    make
    su  <enter root password at prompt>
    make install

Please use the latest (beta) version of AS31.  Perl and
GNU make are also needed, but these are usually already
installed on most linux/unix systems.  Windows users will
need to obtain these tools.  Installation and building on
linux is easy.  If anyone figures out how to make it build
in Windows, hopefully they'll share their setup.

To build the project, just type "make".  Two files are
built, "pm2_mp3.hex" is the code that must be programmed
into the 87C52.  If you purchased this chip from PJRC.COM,
it should have come pre-programmed with this code.  The
file "mp3player.hex" is the actual MP3 player firmware
that is downloaded to the flash memory.  For instructions
to download to a board, see this page:

http://www.pjrc.com/tech/mp3/upgrade.html

Tips For Playing With The Code
------------------------------

For developing code, a file called "main.hex" is built,
which includes only the main program (no device drivers,
filesystem drivers, hardware config data, or misc utilities).
An erase command is installed on the key "X" by default,
and this command will erase only the main program portion
of memory ("Z" to erase the entire flash memory).  This
partial erase allows just the main program to be downloaded,
which speeds up code development considerably.

Happy hacking!



Contact
-------

[e-mail]