TM4C123GXL, Boot Loader, TI Stellaris Debugging

Keith Smith

Other Parts Discussed in Thread: TM4C123GH6PM, EK-TM4C123GXL

I am having difficulty bringing up the boot loader for the TM4C123G Eval Board. I have both execution issues and debugger issues.

I have version 2.1.2.111 of TivaWare. I am using IAR 7.50 EWARM tool chain with the TI Stellaris debugger. The TI Stellaris Setup Interface is set to JTAG. The other option is SWD. Speed is 500kHz.

Problem 1: I build the \Bootloader. It downloads. The program runs, when I break (red hand), the PC is at 0x20000094, the orr instruction of the initialization of the FPU, after the boot loader has been copied to RAM.

ResetISR
//
// Enable the floating-point unit. This must be done here in case any
// later C functions use floating point. Note that some toolchains will
// use the FPU registers for general workspace even if no explicit floating
// point data types are in use.
//
movw r0, #0xED88
movt r0, #0xE000
ldr r1, [r0]
orr r1, r1, #0x00F00000
str r1, [r0]

So I appear to be stuck on the initialization of the FPU the second time. The first time the FPU is initialized was as the boot loader was running in ROM.

What have I done wrong?

------

Problem 2: Setting break points.

With the FPU issue (and any other issue I run into), I want to set break points at specific addresses in ROM, such as 0x0094. I can't use the boot loader symbols as those are mapped to RAM as part of the boot loader design.

The initial address set out of the reset vector is 0x0089. I try to set the 'Run to' address in the Debugger/Setup tab to 0x89, but I get the error 'ARM break points must be set to even addresses'. This is odd, but I am able to work around it.

I see that the reset code really starts at 0x88, so I set the 'Run to' address to 0x88. I get no errors, but debugger doesn't break. It continues to run to 0x20000094.

Am I able to set breakpoints for ROM addresses? What else am I doing wrong?

Below is the log from downloading.

The flash loader specified in the Debugger\Download tab is '$TOOLKIT_DIR$\config\flashloader\TexasInstruments\FlashTC4_H6_o.board'

The device description file in Debugger\Setup tab is '$TOOLKIT_DIR$\CONFIG\debugger\TexasInstruments\TM4C123GH6PM.ddf'.

Mon May 16, 2016 10:02:32: Loaded macro file: C:\Program Files (x86)\IAR Systems\Embedded Workbench 7.3\arm\config\debugger\TexasInstruments\TM4C123.dmac
Mon May 16, 2016 10:02:32: Connecting to TI Stellaris (Probe no: 0E214504)
Mon May 16, 2016 10:02:32: JTAG Speed is set to: 500 kHz
Mon May 16, 2016 10:02:32: JTAG IDCODE = 0x0BA00477
Mon May 16, 2016 10:02:32: AHB-AP ID = 0x00000000
Mon May 16, 2016 10:02:32: AHB-AP ROM = 0x00000000
Mon May 16, 2016 10:02:32: ROM Component ID = 0x00000000
Mon May 16, 2016 10:02:32: Device ID = 0x00000000 (Unknown)
Mon May 16, 2016 10:02:32: Software reset was performed
Mon May 16, 2016 10:02:32: Initial reset was performed
Mon May 16, 2016 10:02:32: 512 bytes downloaded and verified (6.41 Kbytes/sec)
Mon May 16, 2016 10:02:32: Loaded debugee: C:\Program Files (x86)\IAR Systems\Embedded Workbench 7.3\arm\config\flashloader\TexasInstruments\FlashLM3SxxxRAM32K.out
Mon May 16, 2016 10:02:32: Target reset
Mon May 16, 2016 10:02:32: Downloaded C:\Users\smithkm\Perforce\ksmith_SHLLL0924_ProjectSwiftMainline_1073\Firmware\BootLoader\Debug\Exe\Bootloader.out to flash memory.
Mon May 16, 2016 10:02:32: Software reset was performed
Mon May 16, 2016 10:02:32: 1552 bytes downloaded into FLASH and verified (2.56 Kbytes/sec)
Mon May 16, 2016 10:02:32: Loaded debugee: C:\Users\smithkm\Perforce\ksmith_SHLLL0924_ProjectSwiftMainline_1073\Firmware\BootLoader\Debug\Exe\Bootloader.out
Mon May 16, 2016 10:02:32: Software reset was performed
Mon May 16, 2016 10:02:32: Target reset

over 9 years ago

0 Amit Ashara over 9 years ago

TI__Guru**** 244400 points

Hello Keith,

The boot loader is flashed to the internal flash. On execution it is copied to SRAM for execution. So the image is executed from SRAM, but the symbols file are being looked in flash. Even if the FPU is enabled, setting the bit should not cause it to hang there.

Regards
Amit

0 Keith Smith over 9 years ago in reply to Amit Ashara

Intellectual 330 points

Yes, Amit. I understand that the boot loader 'runs' from RAM. There is a small portion of it, though, that does run in ROM upon reset.

One of difficulties I am having is setting breakpoints for the ROM instructions of the boot loader.

I might be able to find the issue with the FPU looping in RAM, if I can step through the ROM instructions, which I reported I am not able to do.

0 Amit Ashara over 9 years ago in reply to Keith Smith

TI__Guru**** 244400 points

Hello Keith

Make sure that the System Reset is set to halt the processor on reset and not run to main.

Regards
Amit

0 Keith Smith over 9 years ago in reply to Amit Ashara

Intellectual 330 points

I checked the 'TI Stellaris' menu item 'Reset will do system reset'. No change.

0 Amit Ashara over 9 years ago in reply to Keith Smith

TI__Guru**** 244400 points

Hello Keith

Since I am not familiar much with the IAR tool set, is there a RUN to option?

Also when you run the boot loader does it run as expected for the serial interface? Or what is the issue?

Regards
Amit

0 Keith Smith over 9 years ago in reply to Amit Ashara

Intellectual 330 points

Yes, there is a 'Run to' option. I enter a hex address, say 0x88, and it does not break at that address.

No, the boot loader gets hung on the FPU instruction in RAM.

0 Amit Ashara over 9 years ago in reply to Keith Smith

TI__Guru**** 244400 points

Hello Keith,

There must be something else, as I have tried the default boot loaders and it always goes to a loop waiting for a data packet on one of the serial interfaces

Regards
Amit

0 Keith Smith over 9 years ago in reply to Amit Ashara

Intellectual 330 points

Default boot loaders? plural? There is more than one? I am using the directory <tivaware>\boot_loader. There are no boot loader examples for the EK-TM4C123GXL. They are only for the DK-TM3C123G.

0 Amit Ashara over 9 years ago in reply to Keith Smith

TI__Guru**** 244400 points

Hello Keith

I meant the boot loader interface"s". I know there are no direct examples in EK-TM4C123GXL and so they have to be derived from the DK-TM4C123G. I can check if I can replicate the issue on the EK-TM4C123GXL, if you can share your project, but this will take me time as I have other debugs ongoing.

Regards
Amit

0 Keith Smith over 9 years ago in reply to Amit Ashara

Intellectual 330 points

OK. What is recommended method for project sharing?

0 Amit Ashara over 9 years ago in reply to Keith Smith

TI__Guru**** 244400 points

Hello Keith

You can upload it to the forum post (if there is no confidential information). Use the rich formatting link on the bottom right of the reply pan to attach the project

Regards
Amit

0 Keith Smith over 9 years ago in reply to Amit Ashara

Intellectual 330 points

Amit - I have created a zip of the project directory. Each time I attach the zip, I get a red error in the dialogue window, with no explanation as to why I have an error.