RTEMS on TMS570

[Pavel Pisa]

Hello Martin,

as for the additional changes to the serial driver, I would wait
for Premysl Houdek to check these and align it with his work.
We need to consider if the whole descriptor should be read/write
or if we provide separate structure/variable for read write field.

As for the problem with running from Flash, if your code combined with
HalCogen sits on the address 0 and starts with vector table
 arm-rtems4.11-nm hello.exe lists

  00000000 T bsp_start_vector_table_begin

then there is no need for vector table remapping into RAM.
Even if your application starts at some offset then IRQ
vector can be bypassed thanks to the CPU and VIM IRQ
bypassing, which we setup but keep off by default.
On the other hand, all other vectors - undefined instruction catch,
invalid memory access would not be handled correctly for any
image which does not start at address 0. Because our intention is
to test mainly from RAM for now, we have enabled memory
range remapping by default and it seems to cause problems
for Flash run.

Give try to the next changes. It resolved problem with your example
code when run from Flash with a drawback that other than IRQ exception
are not handled correctly by RTEMS in this case.

Best wishes,

              Pavel

diff --git a/c/src/lib/libbsp/arm/tms570/irq/irq.c b/c/src/lib/libbsp/arm/tms570/irq/irq.c
index 2e6e3db..552e8b8 100644
--- a/c/src/lib/libbsp/arm/tms570/irq/irq.c
+++ b/c/src/lib/libbsp/arm/tms570/irq/irq.c
@@ -200,7 +200,7 @@ rtems_status_code bsp_interrupt_facility_initialize(void)
    * Disable bypass of CPU level exception table for interrupt entry which
    * can be provided by VIM hardware
    */
-  sctlr &= ~(1 << 24);
+  sctlr |= (1 << 24);
   asm volatile ("mcr p15, 0, %0, c1, c0, 0\n": : "r" (sctlr));

   return RTEMS_SUCCESSFUL;
diff --git a/c/src/lib/libbsp/arm/tms570/startup/bspstart.c b/c/src/lib/libbsp/arm/tms570/startup/bspstart.c
index 31ad1e7..ffeb086 100644
--- a/c/src/lib/libbsp/arm/tms570/startup/bspstart.c
+++ b/c/src/lib/libbsp/arm/tms570/startup/bspstart.c
@@ -33,7 +33,7 @@ void bsp_start( void )
   /* set the cpu mode to supervisor and big endian */
   arm_cpu_mode = 0x213;

-  tms570_pom_remap();
+  //tms570_pom_remap();

   /* Interrupts */
   bsp_interrupt_initialize();