From 3e193cca2c2304fc6a3db751ee0ee733eeef4839 Mon Sep 17 00:00:00 2001
From: Jim Paris <jim@jtan.com>
Date: Tue, 29 Jul 2014 18:06:43 -0400
Subject: [PATCH 1/3] aducrf101: Rearrange stack and heap to maximize available
 stack space

Stack now starts at the top of RAM, heap starts after BSS, and
they grow towards each other.
---
 cpu/arm/aducrf101/Common/GCC/ADuCRF101.ld |  7 +++++--
 cpu/arm/aducrf101/Common/GCC/crt0.S       | 11 -----------
 2 files changed, 5 insertions(+), 13 deletions(-)

diff --git a/cpu/arm/aducrf101/Common/GCC/ADuCRF101.ld b/cpu/arm/aducrf101/Common/GCC/ADuCRF101.ld
index 8d553a5f7..a6effb701 100644
--- a/cpu/arm/aducrf101/Common/GCC/ADuCRF101.ld
+++ b/cpu/arm/aducrf101/Common/GCC/ADuCRF101.ld
@@ -91,10 +91,8 @@ SECTIONS
         } > ram AT > flash
 
         .bss : {
-                /* Stack is in BSS */
                 . = ALIGN(8);
                 __bss_start = .;
-                *(.bss.stack)
                 *(.bss)
                 *(.bss.*)
                 *(COMMON)
@@ -102,4 +100,9 @@ SECTIONS
                 __bss_end = .;
                 end = .;
         } > ram
+
+        /* Heap grows up from "end" (after bss), and stack grows down from
+           the end of RAM. */
+        . = ORIGIN(ram) + LENGTH(ram);
+        stack_end = .;
 }
diff --git a/cpu/arm/aducrf101/Common/GCC/crt0.S b/cpu/arm/aducrf101/Common/GCC/crt0.S
index 592f97902..04b868448 100644
--- a/cpu/arm/aducrf101/Common/GCC/crt0.S
+++ b/cpu/arm/aducrf101/Common/GCC/crt0.S
@@ -32,19 +32,8 @@
  * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#ifndef __STACK_SIZE
-#define __STACK_SIZE 1024
-#endif
-
 .equ SCB_VTOR, 0xE000ED08
 
-/* Stack */
-        .section .bss.stack
-stack_start:
-        .space __STACK_SIZE, 0
-stack_end:
-        .global stack_end
-
 /* Vector table */
         .macro handler name
         .long \name\()

From 4aa2a8b95cafd064c2e75f5614ab057cc0e3a8e8 Mon Sep 17 00:00:00 2001
From: Jim Paris <jim@jtan.com>
Date: Tue, 29 Jul 2014 18:07:33 -0400
Subject: [PATCH 2/3] aducrf101: Add stack pointer sampling, to help debug
 overflows

---
 cpu/arm/aducrf101/clock.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/cpu/arm/aducrf101/clock.c b/cpu/arm/aducrf101/clock.c
index 18e6f7dac..e1feab63f 100644
--- a/cpu/arm/aducrf101/clock.c
+++ b/cpu/arm/aducrf101/clock.c
@@ -43,9 +43,25 @@ static volatile clock_time_t current_clock = 0;
 static volatile unsigned long current_seconds = 0;
 static unsigned int second_countdown = CLOCK_SECOND;
 
+#define SAMPLE_STACK_POINTER
+#ifdef SAMPLE_STACK_POINTER
+volatile uint32_t *__min_sampled_sp = (uint32_t *)0xFFFFFFFF;
+#endif
+
 void
 SysTick_Handler(void)
 {
+#ifdef SAMPLE_STACK_POINTER
+  /* Take note of the lowest stack pointer we ever saw.
+     When compiling against newlib, the total free bytes of
+     RAM not ever used by heap or stack can be found via GDB:
+       (gdb) p (char *)__min_sampled_sp - (char *)_sbrk(0)
+  */
+  uint32_t *sp = (uint32_t *)&sp;
+  if (sp < __min_sampled_sp)
+    __min_sampled_sp = sp;
+#endif
+
   current_clock++;
   if(etimer_pending()) {
     etimer_request_poll();

From 9b76c2fb17cdce4af5707b068324dc0779e5b8c9 Mon Sep 17 00:00:00 2001
From: Jim Paris <jim@jtan.com>
Date: Tue, 29 Jul 2014 18:08:49 -0400
Subject: [PATCH 3/3] aducrf101: Adjust default buffer sizes to fit better in
 available RAM

---
 platform/ev-aducrf101mkxz/contiki-conf.h | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/platform/ev-aducrf101mkxz/contiki-conf.h b/platform/ev-aducrf101mkxz/contiki-conf.h
index 98cc0084f..7cdc5ea7f 100644
--- a/platform/ev-aducrf101mkxz/contiki-conf.h
+++ b/platform/ev-aducrf101mkxz/contiki-conf.h
@@ -89,11 +89,11 @@
 #define XMAC_CONF_COMPOWER                      0
 #define CXMAC_CONF_COMPOWER                     0
 
-#define COLLECT_NBR_TABLE_CONF_MAX_NEIGHBORS    32
+#define COLLECT_NBR_TABLE_CONF_MAX_NEIGHBORS    16
 
 #endif /* WITH_UIP6 */
 
-#define QUEUEBUF_CONF_NUM               16
+#define QUEUEBUF_CONF_NUM               4
 
 #define PACKETBUF_CONF_ATTRS_INLINE     1
 
@@ -109,7 +109,7 @@
 #define ENERGEST_CONF_ON                0
 
 #define AODV_COMPLIANCE
-#define AODV_NUM_RT_ENTRIES             32
+#define AODV_NUM_RT_ENTRIES             16
 
 #define WITH_ASCII                      1
 
@@ -131,8 +131,8 @@
 #define UIP_CONF_IPV6_RPL               1
 #endif
 
-#define NBR_TABLE_CONF_MAX_NEIGHBORS    30
-#define UIP_CONF_MAX_ROUTES             30
+#define NBR_TABLE_CONF_MAX_NEIGHBORS    16
+#define UIP_CONF_MAX_ROUTES             16
 
 #define UIP_CONF_ND6_SEND_RA            0
 #define UIP_CONF_ND6_REACHABLE_TIME     600000
@@ -146,7 +146,7 @@
 #define UIP_CONF_ND6_MAX_PREFIXES       3
 #define UIP_CONF_ND6_MAX_DEFROUTERS     2
 #define UIP_CONF_IP_FORWARD             0
-#define UIP_CONF_BUFFER_SIZE            140
+#define UIP_CONF_BUFFER_SIZE            240
 #define SICSLOWPAN_CONF_FRAG            1
 #define SICSLOWPAN_CONF_MAXAGE          8