[ECOS] Proper Thread Environment (was Re: [ECOS] SPI usage)

[Chuck McManis <cmcmanis at mcmanis dot com>]

At 06:56 AM 2/26/2007, Gary Thomas wrote:
> Try putting these functions into 'main()', which is called
> with a proper thread environment and the kernel+interrupts
> running.

I read this and it reminded me of a question I had, if you have a pointer 
I'd be grateful for it.

Basically when I got the HTTP server to run I did so by loading and running 
the httpd1 test program and noting that it worked fine. Then I tried to run 
a "main" program and the web server simultaneously. Basically I added:

So I had this simple bit of code:

----------------------- bit of lame included code ------------------------

#include <stdio.h>
#include <network.h>

/*
 * Note this is for backward compatibility we don't really
 * think that ECOS will call main, it calls cyg_start and
 * that function will call main.
 */
int
main(int argc, char *argv[]) {
        char buf[2048];

        printf("Welcome to the ECOS world!\n");
        while (1) {
                printf("Enter some text: ");
                gets(buf);
                printf("'%s'\n", buf);
        }
        exit (0);
}
/*
 * This was mostly stolen from the HTTPD test
 */

#define STACK_SIZE (8192 + 0x1000)
static char stack[STACK_SIZE];
static cyg_thread thread_data;
static cyg_handle_t thread_handle;

void
user_thread(cyg_addrword_t p) {

        diag_printf("Startup code for ECOS is running...\n");
        init_all_network_interfaces();
/*
        main(1, aa);
*/
}

void
cyg_user_start(void) {
    cyg_thread_create(10,               // Priority - just a number
                      user_thread,      // entry
                      0,                // entry parameter
                      "simple httpd",   // Name
                      &stack[0],         // Stack
                      STACK_SIZE,        // Size
                      &thread_handle,    // Handle
                      &thread_data       // Thread data structure
            );
    cyg_thread_resume(thread_handle);  // Start it
        cyg_scheduler_start();
}
----------------------- end of lame included code ---------------------------

And it has a really weird way of working. Basically what happens is that 
somehow, main() gets called anyway and runs. And frankly I can't figure out 
how it gets called, but even stranger, its interaction with the console 
blocks the networking stack's attempt to print the result of running DHCP 
which keeps the web server from running. (it nicely demonstrates the Rhine 
"feature" of resetting CR0 however if you don't service received packets ;-)

So what I was looking for, and could not find, was sort of a crt0 type file 
which would provide "the proper thread environment + kernel and interrupts 
running" which would include starting a thread by calling 'main()'. That 
way I could keep eCos code fairly segregated from my "application" which 
normally would run as a process on a UNIX or Linux machine.

Thoughts? Should I just create two threads? Will they still interfere with 
each other's use of the console?

--Chuck



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