boot: Switch to picolibc

keith-packard · nordicjm · commit 610e812c552e · 2025-08-07T13:05:55.000+01:00
Save some memory Signed-off-by: Keith Packard <keithp@keithp.com> (cherry picked from commit 11982df)
diff --git a/boot/zephyr/prj.conf b/boot/zephyr/prj.conf
@@ -32,5 +32,7 @@ CONFIG_LOG_DEFAULT_LEVEL=0
 CONFIG_MCUBOOT_LOG_LEVEL_INF=y
 ### Decrease footprint by ~4 KB in comparison to CBPRINTF_COMPLETE=y
 CONFIG_CBPRINTF_NANO=y
-### Use the minimal C library to reduce flash usage
-CONFIG_MINIMAL_LIBC=y
+### Use picolibc to reduce flash usage
+CONFIG_PICOLIBC=y
+### Disable malloc arena because we don't need it
+CONFIG_COMMON_LIBC_MALLOC_ARENA_SIZE=0
diff --git a/boot/zephyr/socs/esp32_procpu.conf b/boot/zephyr/socs/esp32_procpu.conf
@@ -16,4 +16,5 @@ CONFIG_LOG_DEFAULT_LEVEL=0
 CONFIG_DEBUG=n
 
 CONFIG_HEAP_MEM_POOL_SIZE=4096
-CONFIG_MINIMAL_LIBC=y
+CONFIG_PICOLIBC=y
+CONFIG_COMMON_LIBC_MALLOC_ARENA_SIZE=0
diff --git a/boot/zephyr/socs/esp32c2.conf b/boot/zephyr/socs/esp32c2.conf
@@ -17,4 +17,5 @@ CONFIG_DEBUG=n
 
 CONFIG_XIP=n
 CONFIG_HEAP_MEM_POOL_SIZE=4096
-CONFIG_MINIMAL_LIBC=y
+CONFIG_PICOLIBC=y
+CONFIG_COMMON_LIBC_MALLOC_ARENA_SIZE=0
diff --git a/boot/zephyr/socs/esp32c3.conf b/boot/zephyr/socs/esp32c3.conf
@@ -17,4 +17,5 @@ CONFIG_DEBUG=n
 
 CONFIG_XIP=n
 CONFIG_HEAP_MEM_POOL_SIZE=4096
-CONFIG_MINIMAL_LIBC=y
+CONFIG_PICOLIBC=y
+CONFIG_COMMON_LIBC_MALLOC_ARENA_SIZE=0
diff --git a/boot/zephyr/socs/esp32c6.conf b/boot/zephyr/socs/esp32c6.conf
@@ -17,4 +17,5 @@ CONFIG_DEBUG=n
 
 CONFIG_XIP=n
 CONFIG_HEAP_MEM_POOL_SIZE=4096
-CONFIG_MINIMAL_LIBC=y
+CONFIG_PICOLIBC=y
+CONFIG_COMMON_LIBC_MALLOC_ARENA_SIZE=0
diff --git a/boot/zephyr/socs/esp32s2.conf b/boot/zephyr/socs/esp32s2.conf
@@ -16,4 +16,5 @@ CONFIG_LOG_DEFAULT_LEVEL=0
 CONFIG_DEBUG=n
 
 CONFIG_HEAP_MEM_POOL_SIZE=4096
-CONFIG_MINIMAL_LIBC=y
+CONFIG_PICOLIBC=y
+CONFIG_COMMON_LIBC_MALLOC_ARENA_SIZE=0
diff --git a/boot/zephyr/socs/esp32s3_procpu.conf b/boot/zephyr/socs/esp32s3_procpu.conf
@@ -16,4 +16,5 @@ CONFIG_LOG_DEFAULT_LEVEL=0
 CONFIG_DEBUG=n
 
 CONFIG_HEAP_MEM_POOL_SIZE=4096
-CONFIG_MINIMAL_LIBC=y
+CONFIG_PICOLIBC=y
+CONFIG_COMMON_LIBC_MALLOC_ARENA_SIZE=0
