Difference between uboot-uart.bin and uboot.bin? - embedded

I am trying to flash the very first u-boot binary file (uboot.bin) into blank NOR flash of a brand new blank board which has marvel 370 soc(ARM) using Teraterm(xmodem/ymodem/zmodem)
When I compile the uboot, I get two binaries like uboot-uart.bin and uboot.bin.
What is the difference between two binaries?
I have been instructed to make some dip switch changes and then load uboot-uart.bin first into the prototype board.
From manual I understand that the dip switch setting is to set "Boot from Uart" to Boot source list.
I am new to embedded and want to learn more about this from u-boot perspective. Where can I learn about this?
Would also like to know what these xmodem,ymodem,zmodem things are?
And would also like to learn how to customize u-boot for a custom board using marvel 370 soc(ARM)?
I would be happy if someone can point to good resources.

XModem itself is a quite simple protocol which is meant to send files over a serial link it is explained in detail here.
Most Marvell ARM-Chips in the last couple of years have the possibility to upload a binary via UART using the XModem protocol. There are two ways to do that.
By sending a special sequence to the chip during bootup (which can be done without any changes to the bootstrap options).
By setting up the bootstrap options accordingly (via DIP-Switches in your case)
In both cases the chip will then initiate an Xmodem-download. TeraTerm should have an option to upload files via the xmodem protocol. IIRC it is available under File/Transfer/XModem/Send.
If you know just send your "uboot-uart.bin" file to the Armada 370 (which will take some time). The SoC will now boot the file just like if it was loaded from NAND or any other source.
The only difference between your uboot-uart.bin and uboot.bin is most probably the special header which has to be put in front of the actual uboot-binary, it contains the bootdevice type the image was meant for, the address in memory where the image should be loaded to and a lot of board specific settings. The exact structure and content is usually explained in the very excellent datasheets from Marvell.
For customizing uboot I can only suggest to dig into the code provided by Marvell and change it according to your own board. You'll find the board specific files under boards/Marvell.

Related

LabView dbc-Translator

I have a little over a month to do a project through LabView. It is a program that needs to translate information from a dbc file (dbc battery file) to a specific battery system. In other words, my LabView program should be a translator of the dbc file, which we get from the customer - since I work in a company that deals with battery testing.
Could someone help me and give me some useful advice, link or tutorial, very specific to this issue of mine?
I would be very grateful.
Cheers.
Since we now know that we are talking about CAN database files:
I would recommend to install National Instruments NI-XNET, which is a framework for LIN, CAN and Flexray. It can import such definition files, and makes it easy to access data from the device via the Bus in LabVIEW. There fore an X-NET CAN/LIN/Flexray interface is needed
You can import a dbc file manually, which is OK if there's always the same DBC file.
To do so, open START > National Instruments > NI-XNET Database editor. Open a database, and load your file. You should then see a tree with lots of info. For example, you should see all available CAN frames, and what signals (values) transported in it. You'll also see which bits of a frame are used for which signal, how the bits are interpreted, and how they are converted for example into a voltage.
Finally, it's not more than this to communicate with the device. Right-click on the signal list, choose the just imported database from above, and then select the signals to read.
There is much much more, but I think this is a good starting point.

How can my vhdl code and microblaze co-exist?

Well my problem stated when i had my vhdl code up and running on my Spartan-3a but needed to send and receive data from it to the pc,
I need my vhdl code , so i went for a microplaze structure , problem is I cant understand how will my vhdl code and microblaze co-exist at the same time because every time i program fpga with SDK it deletes my vhdl off the fpga and vise versa with ISE, I dont want to use custom peripherals except if this is the only solution.
Some people just tell me to just use microblaze hdl files produced by EDK, OK but theny aren't I using an unprogrrammed MicroBlaze???
And do i need to go through all of this just to be able to communicate with my vhdl code through pc(NO I CANT USE R232 since i need a speed of 56Mbit/sec)
So here is what i don't understand:
1-IF you implemented microblaze through hardware(HDL from edk to ISE) , isnt it then an un-proggrammed processor?
2-PEOPLE TELL ME i can let microblaze and my vhdl code see each other through GPIO , again how will i implement GPIO and how to connect it to both microblaze and my vhdl code , and how to program microblaze while it in hardware in this situation.
Please any help , its kinda a mess.
It is not that difficult, but unfortunately Xilinx documentation is not that clear.
What you need to do after you are done with your Microblaze code and you feel comfortable with it, is to create a new project in ISE or the one you already had, then add a new file to the project, but instead of adding a VHDL or Verilog file, you must add the system file from EDK.
After you added your XPS project into ISE, you need to do some manual work in order to make things work for you.
Here are a list of things that needs to be done:
You have to create a UCF file that includes all the constraints from EDK
You have to make sure that you have enough space inside your FPGA for both the EDK and
your own code
Synthesize and implement your design using the project in ISE.
Program your FPGA from the bit file generated by ISE
In order to communicate between the MB and your own code, you can do it in many different ways, the easiest way is to use the GPIO block from your MB, then connect those signals to your own code on your top level wrapper.
You maybe able to find some useful information on the lab document and lab material from the following Xilinx page:
enter linkXilinx EDK interface class description here
Accessing the GPIO is pretty simple, you can use the information on this page to get you started:
Reading DIP Switch with MicroBlaze
You may also find this document and related files very useful, it is not for your board, but it covers the exact same thing you are asking for:
Avnet MB tutorial document
I hope this is clear enough.

VGA programming without using interrupt (only registers)

I want to develop a VGA graphics driver (for Linux(Ubuntu)) with support for the basic primitives such as putpixel, drawline, fillrect and bitblt. I want to do it in protected mode.
I´ve been googling for a week and the following four links are the best I have found:
http://www.brackeen....vga/basics.html
http://www.osdever.n...VGA/vga/vga.htm
http://bos.asmhacker...sing%20bios.htm
Unfortunately, the first one uses a BIOS call so I cannot use it. The second link has lots of information on the VGA registers but no examples showing how to make them work together. The third example is a example to switch in 13h mode but i've tried it and nothing happened. Can you guys give me a hint? Thanks in advance!
--Vincenzo
my code at http://bos.asmhackers.net/docs/vga_without_bios/snippet_5/vga.php
works fine if you are in 32bit mode with full hardware access. Unfortunately I doubt that any Linux variant will let you directly access the VGA ports. I'm not sure how you develop this driver, but if you made sure that you have full access to the VGA ports it should work. In my example code I only switch between mode 0x03 and 0x13, but in the folders above you'll be able to find port values for most other common VGA modes, as well as C code to do the switch if you prefer that.
Christoffer code include files are found BOS operating system source code like text.inc and font8x16.inc
http://bos.asmhackers.net/downloads.php
This is coming many many years later but I think it's still very relevant and if somebody is struggling I hope they can find it useful.
First of all, it is completely possible to configure VGA only using registers without interrupts, as hard as it may be. A useful resource about registers and how to configure them can be found here, but unless you have a ton of time to spare to learn how to properly do all of it, move to the following section.
If you wish to really learn how to do it, I suggest going through with the documentation provided earlier. However, some of it is already done!
Chris Giese did a great job demonstrating exactly how to do this for MS-DOS system, and while you may think that doesn't help you, it really does.
Chris's code can be found here. If you want another useful codes check here as well.
Now, while it only works for MS-DOS it's actually easy to convert to other systems. The code already contains all data needed to configure the registers in many different modes. And that's the part that saves you a ton of time going through documentation.
The code uses functions outportb, inportb, which are MS-DOS functions, to write/read single byte to/from a port. Therefore, you have to redefine these functions to read/write for your own system. Redefinition complexity depends on the system you operate on.
In addition, you will also need to provide means to write to physical memory region between 0xA0000-0xBFFFF which corresponds to standard VGA memory area. Once you have that allocated, you need to also redefine the functions pokeb pokew peekb which will help you output things (text or pixel data) on the screen.
One last note: the code is already defined to work with many different modes including both text and display modes.

Porting newlib to a custom ARM setup

this is my first post, and it covers something which I've been trying to get working on and off for about a year now.
Essentially it boils down to the following: I have a copy of newlib which I'm trying to get working on an LPC2388 (an ARM7TDMI from NXP). This is on a linux box using arm-elf-gcc
The question I have is that I've been looking at a lot of the tutorials talking about porting newlib, and they all talk about the stubs (like exit, open, read/write, sbrk), and I have a pretty good idea of how to implement all of these functions. But where should I put them?
I have the newlib distribution from sources.redhat.com/pub/newlib/newlib-1.18.0.tar.gz and after poking around I found "syscalls.c" (in newlib-1.18.0/newlib/libc/sys/arm) which contains all of the stubs which I have to update, but they're all filled in with rather finished looking code (which does NOT seem to work without the crt0.S, which itself does not work with my chip).
Should I just be wiping out those functions myself, and re-writing them? Or should I write them somewhere else. Should I make a whole new folder in newlib/libc/sys with the name of my "architecture" and change the target to match?
I'm also curious if there's proper etiquette on distribution of something like this after releasing it as an open source project. I currently have a script which downloads binutils, arm-elf-gcc, newlib, and gdb, and compiles them. If I am modifying files which are in the newlib directory, should I hand a patch which my script auto-applies? Or should I add the modified newlib to the repository?
Thanks for bothering to read! Following this is a more detailed breakdown of what I'm doing.
For those who want/need more info about my setup:
I'm building a ARM videogame console based loosely on the Uzebox project ( http://belogic.com/uzebox/ ).
I've been doing all sorts of things pulling from a lot of different resources as I try and figure it out. You can read about the start of my adventures here (sparkfun forums, no one responds as I figure it out on my own): forum.sparkfun.com/viewtopic.php?f=11&t=22072
I followed all of this by reading through the Stackoverflow questions about porting newlib and saw a few of the different tutorials (like wiki.osdev.org/Porting_Newlib ) but they also suffer from telling me to implements stubs without mentioning where, who, what, when, or how!
But where should I put them?
You can put them where you like, so long as they exist in the final link. You might incorporate them in the libc library itself, or you might keep that generic, and have the syscalls as a separate target specific object file or library.
You may need to create your own target specific crt0.s and assemble and link it for your target.
A good tutorial by Miro Samek of Quantum Leaps on getting GNU/ARM development up and running is available here. The examples are based on an Atmel AT91 part so you will need to know a little about your NXP device to adapt the start-up code.
A ready made Newlib porting layer for LPC2xxx was available here, but the links ot teh files appear to be broken. The same porting layer is used in Martin Thomas' WinARM project. This is a Windows port of GNU ARM GCC, but the examples included in it are target specific not host specific.
You should only need to modify the porting layer on Newlib, and since it is target and application specific, you need not (in fact probably should not) submit your code to the project.
When I was using newlib that is exactly what I did, blew away crt0.s, syscalls.c and libcfunc.c. My personal preference was to link in the replacement for crt0.s and syscalls.c (rolled the few functions in libcfunc into the syscalls.c replacement) based on the embedded application.
I never had an interest in pushing any of that work back into the distro, so cannot help you there.
You are on the right path though, crt0.S and syscalls.c are where you want to work to customize for your target. Personally I was interested in a C library (and printf) and would primarily neuter all of the functions to return 0 or 1 or whatever it took to get the function to just work and not get in the way of linking, periodically making the file I/O functions operate on linked in data in rom/ram. Basically without replacing or modifying any other files in newlib I had a fair amount of success, so you are on the right path.

Using open source SNES emulator code to turn a rom file into a self-contained executable game

Would it be possible to take the source code from a SNES emulator (or any other game system emulator for that matter) and a game ROM for the system, and somehow create a single self-contained executable that lets you play that particular ROM without needing either the individual rom or the emulator itself to play? Would it be difficult, assuming you've already got the rom and the emulator source code to work with?
It shouldn't be too difficult if you have the emulator source code. You can use a method that is often used to store images in c source files.
Basically, what you need to do is create a char * variable in a header file, and store the contents of the rom file in that variable. You may want to write a script to automate this for you.
Then, you will need to alter the source code so that instead of reading the rom in from a file, it uses the in memory version of the rom, stored in your variable and included from your header file.
It may require a little bit of work if you need to emulate file pointers and such, or you may be lucky and find that the rom loading function just loads the whole file in at once. In this case it would probably be as simple as replacing the file load function with a function to return your pointer.
However, be careful for licensing issues. If the emulator is licensed under the GPL, you may not be legally allowed to store a proprietary file in the executable, so it would be worth checking that, especially before you release / distribute it (if you plan to do so).
Yes, more than possible, been done many times. Google: static binary translation. Graham Toal has a good howto paper on the subject, should show up early in the hits. There may be some code out there I may have left some code out there.
Completely removing the rom may be a bit more work than you think, but not using an emulator, definitely possible. Actually, both requirements are possible and you may be surprised how many of the handheld console games or set top box games are translated and not emulated. Esp platforms like those from Nintendo where there isnt enough processing power to emulate in real time.
You need a good emulator as a reference and/or write your own emulator as a reference. Then you need to write a disassembler, then you have that disassembler generate C code (please dont try to translate directly to another target, I made that mistake once, C is portable and the compilers will take care of a lot of dead code elimination for you). So an instruction of a make believe instruction set might be:
add r0,r0,#2
And that may translate into:
//add r0,r0,#2
r0=r0+2;
do_zflag(r0);
do_nflag(r0);
It looks like the SNES is related to the 6502 which is what Asteroids used, which is the translation I have been working on off and on for a while now as a hobby. The emulator you are using is probably written and tuned for runtime performance and may be difficult at best to use as a reference and to check in lock step with the translated code. The 6502 is nice because compared to say the z80 there really are not that many instructions. As with any variable word length instruction set the disassembler is your first big hurdle. Do not think linearly, think execution order, think like an emulator, you cannot linearly translate instructions from zero to N or N down to zero. You have to follow all the possible execution paths, marking bytes in the rom as being the first byte of an instruction, and not the first byte of an instruction. Some bytes you can decode as data and if you choose mark those, otherwise assume all other bytes are data or fill. Figuring out what to do with this data to get rid of the rom is the problem with getting rid of the rom. Some code addresses data directly others use register indirect meaning at translation time you have no idea where that data is or how much of it there is. Once you have marked all the starting bytes for instructions then it is a trivial task to walk the rom from zero to N disassembling and or translating.
Good luck, enjoy, it is well worth the experience.