diff --git a/armsrc/Standalone/hf_14asniff.c b/armsrc/Standalone/hf_14asniff.c
index 3cbaa05f6..c52928825 100644
--- a/armsrc/Standalone/hf_14asniff.c
+++ b/armsrc/Standalone/hf_14asniff.c
@@ -68,7 +68,7 @@
 
 #define HF_14ASNIFF_LOGFILE "hf_14asniff.trc"
 
-void DownloadTraceInstructions(void) {
+static void DownloadTraceInstructions(void) {
     Dbprintf("");
     Dbprintf("To get the trace from flash and display it:");
     Dbprintf("1. mem spiffs dump o "HF_14ASNIFF_LOGFILE" f trace.trc");
diff --git a/armsrc/Standalone/hf_bog.c b/armsrc/Standalone/hf_bog.c
index c34f0e20a..50e1d824f 100644
--- a/armsrc/Standalone/hf_bog.c
+++ b/armsrc/Standalone/hf_bog.c
@@ -41,7 +41,7 @@ from the client to view the stored quadlets.
 #define HF_BOG_LOGFILE "hf_bog.log"
 
 // This is actually copied from SniffIso14443a
-void RAMFUNC SniffAndStore(uint8_t param) {
+static void RAMFUNC SniffAndStore(uint8_t param) {
 
     iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER);
 
diff --git a/armsrc/Standalone/hf_colin.c b/armsrc/Standalone/hf_colin.c
index 78b36eb78..b1090a019 100644
--- a/armsrc/Standalone/hf_colin.c
+++ b/armsrc/Standalone/hf_colin.c
@@ -104,7 +104,12 @@ static const uint8_t is_hex[] = {
     0, 0,  0,  0,  0,  0,  0,  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  0, 0, 0, 0, 0, 0
 };
 
+// Note: inlining this function would fail with -Os
+#ifdef __OPTIMIZE_SIZE__
+static uint64_t hex2i(const char *s) {
+#else
 static inline uint64_t hex2i(const char *s) {
+#endif
     uint64_t val = 0;
     if (s == NULL || s[0] == 0)
         return 0;
@@ -198,14 +203,14 @@ MFC1KSchema InfiHexact = {.name = "Infineon/Hexact",
 
 int total_schemas = 0;
 
-void add_schema(MFC1KSchema *p, MFC1KSchema a, int *schemas_counter) {
+static void add_schema(MFC1KSchema *p, MFC1KSchema a, int *schemas_counter) {
     if (*schemas_counter < MAX_SCHEMAS) {
         p[*schemas_counter] = a;
         *schemas_counter += 1;
     }
 }
-
-void delete_schema(MFC1KSchema *p, int *schemas_counter, int index) {
+/*
+static void delete_schema(MFC1KSchema *p, int *schemas_counter, int index) {
     if (*schemas_counter > 0 && index < *schemas_counter && index > -1) {
         int last_index = *schemas_counter - 1;
         for (int i = index; i < last_index; i++) {
@@ -214,23 +219,23 @@ void delete_schema(MFC1KSchema *p, int *schemas_counter, int index) {
         *schemas_counter -= 1;
     }
 }
-
-void cjSetCursFRight(void) {
+*/
+static void cjSetCursFRight(void) {
     vtsend_cursor_position(NULL, 98, (currfline));
     currfline++;
 }
 
-void cjSetCursRight(void) {
+static void cjSetCursRight(void) {
     vtsend_cursor_position(NULL, 59, (currline));
     currline++;
 }
 
-void cjSetCursLeft(void) {
+static void cjSetCursLeft(void) {
     vtsend_cursor_position(NULL, 0, (curlline));
     curlline++;
 }
 
-void cjTabulize(void) { DbprintfEx(FLAG_RAWPRINT, "\t\t\t"); }
+static void cjTabulize(void) { DbprintfEx(FLAG_RAWPRINT, "\t\t\t"); }
 
 /*
 void cjPrintKey(uint64_t key, uint8_t *foundKey, uint16_t sectorNo, uint8_t type) {
@@ -240,7 +245,7 @@ foundKey[5]); cjSetCursRight(); DbprintfEx(FLAG_NEWLINE, "SEC: %02x | KEY : %s |
 }
 */
 
-char *ReadSchemasFromSPIFFS(char *filename) {
+static char *ReadSchemasFromSPIFFS(char *filename) {
     SpinOff(0);
 
     int changed = rdv40_spiffs_lazy_mount();
@@ -255,7 +260,7 @@ char *ReadSchemasFromSPIFFS(char *filename) {
     return (char *)mem;
 }
 
-void add_schemas_from_json_in_spiffs(char *filename) {
+static void add_schemas_from_json_in_spiffs(char *filename) {
 
     char *jsonfile = ReadSchemasFromSPIFFS((char *)filename);
 
@@ -275,7 +280,7 @@ void add_schemas_from_json_in_spiffs(char *filename) {
     }
 }
 
-void ReadLastTagFromFlash(void) {
+static void ReadLastTagFromFlash(void) {
     SpinOff(0);
     LED_A_ON();
     LED_B_ON();
diff --git a/armsrc/Standalone/hf_legic.c b/armsrc/Standalone/hf_legic.c
index d1add7fe3..5bcbfca63 100644
--- a/armsrc/Standalone/hf_legic.c
+++ b/armsrc/Standalone/hf_legic.c
@@ -44,7 +44,7 @@
  *
 */
 
-void DownloadLogInstructions(void) {
+static void DownloadLogInstructions(void) {
     Dbprintf("");
     Dbprintf("[=] List all dumps from flash:");
     Dbprintf("[=]   " _YELLOW_("-") " mem spiffs tree");
@@ -53,7 +53,7 @@ void DownloadLogInstructions(void) {
     Dbprintf("[=]   " _YELLOW_("-") " mem spiffs dump o hf-legic-UID-dump.bin f hf-legic-UID-dump.bin");
 }
 
-void save_dump_to_file(legic_card_select_t *p_card) {
+static void save_dump_to_file(legic_card_select_t *p_card) {
 
 #ifdef WITH_FLASH
 
diff --git a/armsrc/Standalone/lf_em4100emul.c b/armsrc/Standalone/lf_em4100emul.c
index 166c668f8..6ad2580a4 100644
--- a/armsrc/Standalone/lf_em4100emul.c
+++ b/armsrc/Standalone/lf_em4100emul.c
@@ -18,6 +18,7 @@
 #include "ticks.h"
 #include "string.h"
 #include "BigBuf.h"
+#include "commonutil.h"
 
 #define MAX_IND 16 // 4 LEDs - 2^4 combinations
 #define CLOCK 64 //for 125kHz
@@ -34,7 +35,7 @@ void ModInfo(void) {
     DbpString("  LF EM4100 simulator standalone mode");
 }
 
-uint64_t ReversQuads(uint64_t bits) {
+static uint64_t ReversQuads(uint64_t bits) {
     uint64_t result = 0;
     for (int i = 0; i < 16; i++) {
         result += ((bits >> (60 - 4 * i)) & 0xf) << (4 * i);
@@ -42,14 +43,14 @@ uint64_t ReversQuads(uint64_t bits) {
     return result >> 24;
 }
 
-void FillBuff(uint8_t bit) {
+static void FillBuff(uint8_t bit) {
     memset(bba + buflen, bit, CLOCK / 2);
     buflen += (CLOCK / 2);
     memset(bba + buflen, bit ^ 1, CLOCK / 2);
     buflen += (CLOCK / 2);
 }
 
-void ConstructEM410xEmulBuf(uint64_t id) {
+static void ConstructEM410xEmulBuf(uint64_t id) {
 
     int i, j, binary[4], parity[4];
     buflen = 0;
@@ -70,7 +71,7 @@ void ConstructEM410xEmulBuf(uint64_t id) {
     FillBuff(0);
 }
 
-void LED_Slot(int i) {
+static void LED_Slot(int i) {
     LEDsoff();
     if (slots_count > 4) {
         LED(i % MAX_IND, 0); //binary indication for slots_count > 4
diff --git a/armsrc/Standalone/lf_em4100rwc.c b/armsrc/Standalone/lf_em4100rwc.c
index 19aa39919..a7364bd81 100644
--- a/armsrc/Standalone/lf_em4100rwc.c
+++ b/armsrc/Standalone/lf_em4100rwc.c
@@ -27,6 +27,7 @@
 #include "string.h"
 #include "BigBuf.h"
 #include "spiffs.h"
+#include "commonutil.h"
 
 #ifdef WITH_FLASH
 #include "flashmem.h"
@@ -47,7 +48,7 @@ void ModInfo(void) {
     DbpString("  LF EM4100 read/write/clone mode");
 }
 
-uint64_t ReversQuads(uint64_t bits) {
+static uint64_t ReversQuads(uint64_t bits) {
     uint64_t result = 0;
     for (int i = 0; i < 16; i++) {
         result += ((bits >> (60 - 4 * i)) & 0xf) << (4 * i);
@@ -55,14 +56,14 @@ uint64_t ReversQuads(uint64_t bits) {
     return result >> 24;
 }
 
-void FillBuff(uint8_t bit) {
+static void FillBuff(uint8_t bit) {
     memset(bba + buflen, bit, CLOCK / 2);
     buflen += (CLOCK / 2);
     memset(bba + buflen, bit ^ 1, CLOCK / 2);
     buflen += (CLOCK / 2);
 }
 
-void ConstructEM410xEmulBuf(uint64_t id) {
+static void ConstructEM410xEmulBuf(uint64_t id) {
 
     int i, j, binary[4], parity[4];
     buflen = 0;
@@ -83,7 +84,7 @@ void ConstructEM410xEmulBuf(uint64_t id) {
     FillBuff(0);
 }
 
-void LED_Slot(int i) {
+static void LED_Slot(int i) {
     LEDsoff();
     if (slots_count > 4) {
         LED(i % MAX_IND, 0); //binary indication, usefully for slots_count > 4
@@ -92,7 +93,7 @@ void LED_Slot(int i) {
     }
 }
 
-void FlashLEDs(uint32_t speed, uint8_t times) {
+static void FlashLEDs(uint32_t speed, uint8_t times) {
     for (int i = 0; i < times * 2; i++) {
         LED_A_INV();
         LED_B_INV();
@@ -103,9 +104,9 @@ void FlashLEDs(uint32_t speed, uint8_t times) {
 }
 
 #ifdef WITH_FLASH
-void SaveIDtoFlash(int addr, uint64_t id) {
+static void SaveIDtoFlash(int addr, uint64_t id) {
     uint8_t bt[5];
-    char *filename = "emdump";
+    const char *filename = "emdump";
     rdv40_spiffs_mount();
     for (int i = 0; i < 5; i++) {
         bt[4 - i] = (uint8_t)(id >> 8 * i & 0xff);
diff --git a/armsrc/Standalone/lf_icehid.c b/armsrc/Standalone/lf_icehid.c
index 29a87305d..7ac91d126 100644
--- a/armsrc/Standalone/lf_icehid.c
+++ b/armsrc/Standalone/lf_icehid.c
@@ -54,7 +54,7 @@
 #define LF_HIDCOLLECT_LOGFILE "lf_hidcollect.log"
 
 
-void DownloadLogInstructions(void) {
+static void DownloadLogInstructions(void) {
     Dbprintf("");
     Dbprintf("[=] To get the logfile from flash and display it:");
     Dbprintf("[=] " _YELLOW_("1.") " mem spiffs dump o "LF_HIDCOLLECT_LOGFILE" f "LF_HIDCOLLECT_LOGFILE);
@@ -64,7 +64,7 @@ void DownloadLogInstructions(void) {
 
 bool log_exists;
 
-void append(uint8_t *entry, size_t entry_len) {
+static void append(uint8_t *entry, size_t entry_len) {
 
     LED_B_ON();
     if (log_exists == false) {
@@ -76,7 +76,7 @@ void append(uint8_t *entry, size_t entry_len) {
     LED_B_OFF();
 }
 
-uint32_t IceEM410xdemod(void) {
+static uint32_t IceEM410xdemod(void) {
 
     uint8_t *dest = BigBuf_get_addr();
     size_t idx = 0;
@@ -128,7 +128,7 @@ uint32_t IceEM410xdemod(void) {
     return PM3_SUCCESS;
 }
 
-uint32_t IceAWIDdemod(void) {
+static uint32_t IceAWIDdemod(void) {
 
     uint8_t *dest = BigBuf_get_addr();
     size_t size = MIN(12800, BigBuf_max_traceLen());
@@ -180,7 +180,7 @@ uint32_t IceAWIDdemod(void) {
     return PM3_SUCCESS;
 }
 
-uint32_t IceIOdemod(void) {
+static uint32_t IceIOdemod(void) {
 
     int dummyIdx = 0;
     uint8_t version = 0, facilitycode = 0;
@@ -224,7 +224,7 @@ uint32_t IceIOdemod(void) {
     return PM3_SUCCESS;
 }
 
-uint32_t IceHIDDemod(void) {
+static uint32_t IceHIDDemod(void) {
 
     int dummyIdx = 0;
 
diff --git a/armsrc/spiffs.c b/armsrc/spiffs.c
index 0ade78239..4267412c5 100644
--- a/armsrc/spiffs.c
+++ b/armsrc/spiffs.c
@@ -400,20 +400,20 @@ int rdv40_spiffs_lazy_mount_rollback(int changed) {
 // statement or some function taking function parameters
 // TODO : forbid writing to a filename which already exists as lnk !
 // TODO : forbid writing to a filename.lnk which already exists without lnk !
-int rdv40_spiffs_write(char *filename, uint8_t *src, uint32_t size, RDV40SpiFFSSafetyLevel level) {
+int rdv40_spiffs_write(const char *filename, uint8_t *src, uint32_t size, RDV40SpiFFSSafetyLevel level) {
     RDV40_SPIFFS_SAFE_FUNCTION(
         write_to_spiffs(filename, src, size);
     )
 }
 
-int rdv40_spiffs_append(char *filename, uint8_t *src, uint32_t size, RDV40SpiFFSSafetyLevel level) {
+int rdv40_spiffs_append(const char *filename, uint8_t *src, uint32_t size, RDV40SpiFFSSafetyLevel level) {
     RDV40_SPIFFS_SAFE_FUNCTION(
         append_to_spiffs(filename, src, size);
     )
 }
 
 // todo integrate reading symlinks transparently
-int rdv40_spiffs_read(char *filename, uint8_t *dst, uint32_t size, RDV40SpiFFSSafetyLevel level) {
+int rdv40_spiffs_read(const char *filename, uint8_t *dst, uint32_t size, RDV40SpiFFSSafetyLevel level) {
     RDV40_SPIFFS_SAFE_FUNCTION(
         read_from_spiffs(filename, dst, size);
     )
diff --git a/armsrc/spiffs.h b/armsrc/spiffs.h
index b3578f599..5a9e58a94 100644
--- a/armsrc/spiffs.h
+++ b/armsrc/spiffs.h
@@ -37,8 +37,8 @@ int rdv40_spiffs_check(void);
 int rdv40_spiffs_lazy_unmount(void);
 int rdv40_spiffs_lazy_mount(void);
 int rdv40_spiffs_lazy_mount_rollback(int changed);
-int rdv40_spiffs_write(char *filename, uint8_t *src, uint32_t size, RDV40SpiFFSSafetyLevel level);
-int rdv40_spiffs_read(char *filename, uint8_t *dst, uint32_t size, RDV40SpiFFSSafetyLevel level);
+int rdv40_spiffs_write(const char *filename, uint8_t *src, uint32_t size, RDV40SpiFFSSafetyLevel level);
+int rdv40_spiffs_read(const char *filename, uint8_t *dst, uint32_t size, RDV40SpiFFSSafetyLevel level);
 int rdv40_spiffs_rename(char *old_filename, char *new_filename, RDV40SpiFFSSafetyLevel level);
 int rdv40_spiffs_remove(char *filename, RDV40SpiFFSSafetyLevel level);
 int rdv40_spiffs_read_as_symlink(char *filename, uint8_t *dst, uint32_t size, RDV40SpiFFSSafetyLevel level);
@@ -53,7 +53,7 @@ void rdv40_spiffs_safe_print_fsinfo(void);
 int rdv40_spiffs_make_symlink(char *linkdest, char *filename, RDV40SpiFFSSafetyLevel level);
 void append_to_spiffs(const char *filename, uint8_t *src, uint32_t size);
 int rdv40_spiffs_copy(char *src, char *dst, RDV40SpiFFSSafetyLevel level);
-int rdv40_spiffs_append(char *filename, uint8_t *src, uint32_t size, RDV40SpiFFSSafetyLevel level);
+int rdv40_spiffs_append(const char *filename, uint8_t *src, uint32_t size, RDV40SpiFFSSafetyLevel level);
 int rdv40_spiffs_stat(char *filename, uint32_t *buf, RDV40SpiFFSSafetyLevel level);
 uint32_t size_in_spiffs(const char *filename);
 int exists_in_spiffs(const char *filename);
diff --git a/armsrc/string.c b/armsrc/string.c
index 95b53b6ec..8dbe26808 100644
--- a/armsrc/string.c
+++ b/armsrc/string.c
@@ -247,7 +247,7 @@ int strncmp(const char *s1, const char *s2, size_t n) {
 
 
 #define isspace(a) __extension__ ({ unsigned char bb__isspace = (a) - 9; bb__isspace == (' ' - 9) || bb__isspace <= (13 - 9); })
-/*
+
 unsigned long strtoul(const char *p, char **out_p, int base) {
     unsigned long v = 0;
 
@@ -319,7 +319,6 @@ long strtol(const char *p, char **out_p, int base) {
     if (out_p) *out_p = (char *)p;
     return v;
 }
-*/
 
 char c_tolower(int c) {
     // (int)a = 97, (int)A = 65
diff --git a/armsrc/string.h b/armsrc/string.h
index 0ebb4ab54..f8388d0a1 100644
--- a/armsrc/string.h
+++ b/armsrc/string.h
@@ -33,6 +33,8 @@ char *strrchr(const char *s, int c);
 size_t strcspn(const char *s1, const char *s2);
 char *strpbrk(const char *s1, const char *s2);
 int strncmp(const char *s1, const char *s2, size_t n);
+unsigned long strtoul(const char *p, char **out_p, int base);
+long strtol(const char *p, char **out_p, int base);
 char c_tolower(int c);
 char c_isprint(unsigned char c);