Nice to meet you all!
Recently I am trying to port the FreeRTOS on some gerneral 80C51 Core based MCU with 2K External memory. I made referenced to the Cygnal 8051 based port. However, I find that I fail to run even a single task. I found that it fails in the pvPortMalloc(). I found that the following statement always false:
if( ( usNextFreeByte + usWantedSize ) < portTOTAL_HEAP_SIZE )
I am using the snapshot version of SDCC with the library for reenterant from FreeRTOS websites. I had modify the portSTACK_START according to the MEM files generated by the SDCC. I had also modify the variables in portmacro.h. Any idea for this problems? Thank you~
The portTOTAL_HEAP_SIZE was set to 1500. The memory bank was set to 0 (so that except the R0-R7,all the others 256 bytes was used for SP, right?) There is no link warnings.
I had tried to implement some simple timer program to change the GPIO port(to flash LED)(without RTOS), everythings seems to be alright. The timer should be working fine.
Anyway thanks for your help.
In fact 2KBytes external memory , is that enough for 1x - 20 tasks for FreeRTOS? I am running the chip @ 40Mhz (12 Clocks for 1 intruction cycle).
>Is there a memroy bank set up large enough to hold the entire array?
I think you may be getting PIC and 8051 confused here.
The PIC port has the .lkr file in which the banking requires adjustment. That is not relevant here.
With the 8051 port the external RAM size is set in the makefile, using the --xram-size option. In the download this is set to 8448, and for 2K external RAM should be adjusted to 2048.
[this will probably look a mess when pasted here as the spacing will be all wrong]
If you see the entry Fheap_1$xHeap$0$0 you can see that it starts at A1 and ends at 18A5, so is approx 6K big. What do you see for these figures in your map file?
Also note my comments regarding the --xram-size setting within the makefile made in a different post.
Thanks a lot for your help, the following would be my Mem location for XHeap function:
Area Addr Size Decimal Bytes (Attributes)
-------------------------------- ---- ---- ------- ----- ------------
XSEG 0000 07BB = 1979. bytes (REL,CON,XDATA)
Thank you. Richard. I will have another trial tonight.
Another question, is that for my case, the following definition needed to be change: #define portMINIMAL_STACK_SIZE ( ( unsigned portSHORT ) 200 - ( unsigned portSHORT ) portSTACK_START )
if not, the size for those idle task would be quite large and 2K external memory seems cannot hold much tasks at the same time…thank you~
I have tried to add the following function call to the main in main.c
vPortInitialiseBlocks();
and I change the following #define portMINIMAL_STACK_SIZE ( ( unsigned portSHORT ) 100 - ( unsigned portSHORT ) portSTACK_START )
This makes the sTaskCreate 0x00 in return
However, I still fail to run a single task, the task as follow:
static void prvToggleOnBoardLED2( void )
{
/* If the on board LED is on, turn it off and visa versa. */
if( P1 & 0x20 )
{
P1 &= ~0x20;
}
else
{
P1 |= 0x20;
}
}
/*-----------------------------------------------------------*/
static void vToggleLED( void *pvParameters )
{
Sorry for disturbing all of you again. I found that some static variables are not being initialised. Is that the lastest snapshot version of SDCC imcomplatible with the reenterant library?
If that is the fact, I may try to implement the freeRTOS by using Keil C.
Thank you~
1 more question:
When main() try to call sPortStartScheduler()
if I have just one single task made, the pxCurrentTCB should be points to the TCB of that task or not? and the value stored inside the *pxCurrentTCB should be the stack size (17 in this case?)
Is this the case when you try compiling a simple "hello world" type program? Maybe the variables are getting initialised, but then corrupted.
Can you look at the startup asm code to see where the initialisation should occur?
If you find that you get the same problem with a simple “hello world” program then try sending the program (it must be small and compile ‘out of the box’) to the sdcc support mail list. http://sdcc.sourceforge.net has the list information.
You will actually have two tasks - because the idle task is created automatically - but the pxCurrentTCB should point to your task as you say.
*pxCurrentTCB will not however be the stack size - but a pointer to the top of the task stack.
I suspect you may be getting some corruption somewhere.
I don’t know what your debug system is like. If you can stop the program where main() is called then take a look at the static variable values. If they are correct then you can step through until you see it change to the incorrect value.
it is a pity for me to have just a 89C51SND1 , it is a 8051 based core chip running @ 20Mhz (X2 mode just need 6 clock period per instruction, thus act as a 8051 @ 40MHz)… I do not have any debug system except 2 leds…
void main( void )
{
----// First check if the variable starts with the
----// expected value.
----if( variable == expected value )
--------Led1 = on;
----else
--------Led2 = on;
yup , I am now using this method… however, it must be the most troublesome way… as I cannot check for the stack pointer and the internal / external memory map.
I could just guess for my expect value . Some parts I would use some debug marco to swap out the whole byte for checking…
. Some parts I would use some debug marco to swap out the whole byte for checking…