AM57x GP EVM UART boot

Roger McCalman51

Other Parts Discussed in Thread: AM5726, AM5728

I have a Am5726 evm and wish to check the boot via uart for our own custom designed board. I have changed the jumpers J3,J4 and J6 to select the UART boot mode. I have written a perl script based on the serial-boot.pl to dump the raw data and look for the ASCI-ID sequence. I also have added a loop that fetches the ASIC-ID 3 times using the boot message 0xf003003 to verify that I have the communications working ok. After sending the u-boot-spl.bin file from u-boot-2015.07+gitAUTOINC+5922e09363/spl I get no response on the serial port so the download of u-boot over y-modem (minicom) does not start. I configured u-boot using 'make am57xx_evm_defconfig' and it built ok. Is there something I am missing?

over 7 years ago

0 Yordan Kovachev over 7 years ago

TI__Guru**** 161600 points

Hi,

Have a look at this thread:

Uart boot is discussed in details there.

You probably experience the following problem: "the PMIC cuts off the power, if during a specified time (~10-15 seconds) an image does NOT take over & set the PMIC to continue powering the board. Therefore if you don't have any image loaded in the DDR & executed by ROM code during that time the power will be cut off (power led on the board stops glowing, which indicates when power is turned off). "

Workaround for AM5728 GP EVM IS:

" To overcome this "limitation" populate J5 (or stuff a wire/paper clip/staple into it) on newer boards, or swap R23 with R28 on older boards. "

Best Regards,

Yordan

0 Roger McCalman51 over 7 years ago in reply to Yordan Kovachev

Intellectual 335 points

I have just checked and the power led stays on - so I don't think that is the problem.

Is there any more information about what happens when the ROM transfers control to the loaded image? I have ordered a JTAG debugger to help but in the meantime I added a bit of code to send a byte to the UART3 to see if the code was being executed but got no response.

0 Yordan Kovachev over 7 years ago in reply to Roger McCalman51

TI__Guru**** 161600 points

Roger,

All my experience booting AM572x GP EVM through UART is summarized in the e2e thread I provided in my previous post.

When you finish the binary transfer of the u-boot-spl.bin do you start getting CCCC in your debug terminal? Have you added #define CONFIG_SPL_YMODEM_SUPPORT in beagle_x15.h to enable the xmodem support in spl & u-boot?

Best Regards,
Yordan

0 Roger McCalman51 over 7 years ago in reply to Yordan Kovachev

Intellectual 335 points

Thanks.

Adding

Index: include/configs/am57xx_evm.h
===================================================================
--- include/configs/am57xx_evm.h (revision 21730)
+++ include/configs/am57xx_evm.h (working copy)
@@ -19,6 +19,7 @@
#endif

#define CONFIG_BOARD_EARLY_INIT_F
+#define CONFIG_SPL_YMODEM_SUPPORT 1

#define CONFIG_NR_DRAM_BANKS 2

fixed it.

0 kishore akkala over 7 years ago in reply to Roger McCalman51

Intellectual 255 points

Hi Roger & Yordan,

We are trying to boot the AM572x_GP_EVM using uart peripheral mode. we are not able to get the serial-boot.pl file , can you please share this file with us. In our case always getting "!VA" message on the processor debug port.

1) How you are sending "u-boot-spl.bin" from HOST machine to Board? (also please share me serial port settings).

2) How to send "u-boot.img" file ?

Regards

Kishore Kumar

0 Yordan Kovachev over 7 years ago in reply to kishore akkala

TI__Guru**** 161600 points

Hi,

Here is the perl script:
processors.wiki.ti.com/.../File:Serial-boot.zip

1. you use the perl script to send the u-boot-spl.bin
2. Once the spl is loaded to your board, you should immediately open a serial console, i.e. minicom or teraterm & you will see CCCCCC on it.
3. Use minicom (Ctrl+A -> S) or teraterm or whatever terminal program you use to send u-boot.img via xmodem.

Best Regards,
Yordan

0 kishore akkala over 7 years ago in reply to Yordan Kovachev

Intellectual 255 points

Thank you Yordan.

Now it working in windows. But in Linux it is giving error saying "Unable to find required Perl module Device::SerialPort"

is any package I have to install in u-buntu PC?

Regards
Kishore Kumar A

0 Yordan Kovachev over 7 years ago in reply to kishore akkala

TI__Guru**** 161600 points

Yes, if you open the script itself and study how it works, you'll see that this is the first thing noted:
# INSTALLATION NOTES:
# -------------------
# WIN32:
# This package depends on Win32::SerialPort if using windows
# Download from www.bribes.org/.../
# PPD file and tgz to c:\perl, open a cmd and cd c:\perl
# run ppm install Win32-SerialPort.ppd
#
# Linux/Other OS:
# This package depends on Device::SerialPort if using any other OS.
# Download this using cpan -> cpan install Device::SerialPort
#
# The perl script by itself requires only r/w permission to serial port

Best Regards,
Yordan

0 Roger McCalman51 over 7 years ago in reply to Yordan Kovachev

Intellectual 335 points

Hi,

I used the perl script as an example and re-wrote it to not use Device::SerialPort as I only needed it to work on Linux and I prefer to install only packages from yum as it makes maintenance simpler.

The setup of the serial port is
#!/usr/bin/perl
#
use strict;
use warnings;
use POSIX qw(:termios_h);
my ($term, $oterm, $echo, $noecho, $fd_stdin);

my $fh;
open($fh, "+<", "/dev/ttyUSB0") || die "failed to open tty - $!";

$fd_stdin = fileno($fh);
$term = POSIX::Termios->new();
$term->getattr($fd_stdin);
$oterm = $term->getlflag();

$echo = ECHO | ECHOK | ICANON;
$noecho = $oterm & ~$echo;

$term->setlflag($noecho); # ok, so i don't want echo either

my $cflag = $term->getcflag();
my $ocflag = $cflag;
$cflag &= ~PARODD;
$cflag |= PARENB;
printf("clfag 0x%08x->0x%08x\n", $ocflag, $cflag);
$term->setcflag($cflag);
$term->setcc(VTIME, 0);
$term->setcc(VMIN, 0);
$term->setattr($fd_stdin, TCSANOW);
...

I also modified the SPL to allow loading u-boot from tftp rather than via x-modem. The perl code is not pretty and I'm not sure if I can release it for general use.

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AM57x GP EVM UART boot