Fix up linker script; improve startup code; printf to USB.

1 files changed, 2 insertions, 1 deletions

diff --git a/stm/malloc0.c b/stm/malloc0.c
index 55c1ae8044..1b45846e6f 100644
--- a/stm/malloc0.c
+++ b/stm/malloc0.c
@@ -5,7 +5,8 @@ static uint32_t mem = 0;
 
 void *malloc(size_t n) {
     if (mem == 0) {
-        mem = 0x20008000; // need to use big ram block so we can execute code from it; start up a bit in case that's where bss is...?
+        extern uint32_t _heap_start;
+        mem = &_heap_start; // need to use big ram block so we can execute code from it (is it true that we can't execute from CCM?)
     }
     void *ptr = (void*)mem;
     mem = (mem + n + 3) & (~3);