arch: rp2040: Fix the initial stack pointer

Summary: - The NuttX for raspberrypi-pico boots via the boot_stage2 provided by the pico-sdk which sets the MSP at the end of the SRAM. - However, the NuttX expects the MSP is set to the top of the idle stack. - This commit fixes this issue. Impact: - None Testing: - Tested with nsh, nshsram and smp configrations
psanyi · Apr 25, 2021 · dc9223f · dc9223f
1 parent 05f743a
commit dc9223f
Showing 1 changed file with 4 additions and 0 deletions.
diff --git a/arch/arm/src/rp2040/rp2040_start.c b/arch/arm/src/rp2040/rp2040_start.c
@@ -89,6 +89,10 @@ void __start(void)
   uint32_t *dest;
   int i;
 
+  /* Set MSP to the top of the IDLE stack */
+
+  __asm__ __volatile__ ("\tmsr msp, %0\n" :: "r" (g_idle_topstack));
+
   if (up_cpu_index() != 0)
     {
       while (1)