pgmspace.h

#ifndef __PGMSPACE_H_
#define __PGMSPACE_H_

#include <stdint.h>
#include <stdio.h>


#ifdef __ets__

#include "ets_sys.h"
#include "osapi.h"

#define PROGMEM     ICACHE_RODATA_ATTR
#define PGM_P  		const char *
#define PGM_VOID_P  const void *
#define PSTR(s) (__extension__({static const char __c[] PROGMEM = (s); &__c[0];}))
#else //__ets__
#define PROGMEM
#define PGM_P  		const char *
#define PGM_VOID_P  const void *
#define PSTR(s)     (s)

#endif // __ets__


#ifdef __cplusplus
extern "C" {
#endif

#define _SFR_BYTE(n) (n)

typedef void prog_void;
typedef char prog_char;
typedef unsigned char prog_uchar;
typedef int8_t prog_int8_t;
typedef uint8_t prog_uint8_t;
typedef int16_t prog_int16_t;
typedef uint16_t prog_uint16_t;
typedef int32_t prog_int32_t;
typedef uint32_t prog_uint32_t;

#define SIZE_IRRELEVANT 0x7fffffff

// memchr_P and memrchr_P are not implemented due to danger in its use, and
// how uninteresting their use is
// since its a flash string, you should already know where the char is within it,
// further, it could return a pointer into the flash memory that is not 32bit aligned
// which could cause an exception if read
// PGM_VOID_P memchr_P(PGM_VOID_P bufP, int c, size_t count);
// PGM_VOID_P memrchr_P(PGM_VOID_P bufP, int c, size_t count);

int memcmp_P(const void* buf1, PGM_VOID_P buf2P, size_t size);
// memccpy_P is only valid when used with pointers to 8bit data, due to size aligned pointers
// and endianess of the values greater than 8bit, matching c may return invalid aligned pointers
void* memccpy_P(void* dest, PGM_VOID_P src, int c, size_t count);
void* memmem_P(const void* buf, size_t bufSize, PGM_VOID_P findP, size_t findPSize);
void* memcpy_P(void* dest, PGM_VOID_P src, size_t count);

char* strncpy_P(char* dest, PGM_P src, size_t size);
#define strcpy_P(dest, src)          strncpy_P((dest), (src), SIZE_IRRELEVANT)

char* strncat_P(char* dest, PGM_P src, size_t size);
#define strcat_P(dest, src)          strncat_P((dest), (src), SIZE_IRRELEVANT)

int strncmp_P(const char* str1, PGM_P str2P, size_t size);
#define strcmp_P(str1, str2P)          strncmp_P((str1), (str2P), SIZE_IRRELEVANT)

int strncasecmp_P(const char* str1, PGM_P str2P, size_t size);
#define strcasecmp_P(str1, str2P)          strncasecmp_P((str1), (str2P), SIZE_IRRELEVANT)

size_t strnlen_P(PGM_P s, size_t size);
#define strlen_P(strP)          strnlen_P((strP), SIZE_IRRELEVANT)

char* strstr_P(const char* haystack, PGM_P needle);

int	printf_P(PGM_P formatP, ...) __attribute__((format(printf, 1, 2)));
int	sprintf_P(char *str, PGM_P formatP, ...) __attribute__((format(printf, 2, 3)));
int	snprintf_P(char *str, size_t strSize, PGM_P formatP, ...) __attribute__((format(printf, 3, 4)));
int	vsnprintf_P(char *str, size_t strSize, PGM_P formatP, va_list ap) __attribute__((format(printf, 3, 0)));

// flash memory must be read using 32 bit aligned addresses else a processor
// exception will be triggered
// order within the 32 bit values are
// --------------
// b3, b2, b1, b0
//     w1,     w0

#ifdef __ets__

#define pgm_read_with_offset(addr, res) \
  asm("extui    %0, %1, 0, 2\n"     /* Extract offset within word (in bytes) */ \
      "sub      %1, %1, %0\n"       /* Subtract offset from addr, yielding an aligned address */ \
      "l32i.n   %1, %1, 0x0\n"      /* Load word from aligned address */ \
      "slli     %0, %0, 3\n"        /* Mulitiply offset by 8, yielding an offset in bits */ \
      "ssr      %0\n"               /* Prepare to shift by offset (in bits) */ \
      "srl      %0, %1\n"           /* Shift right; now the requested byte is the first one */ \
      :"=r"(res), "=r"(addr) \
      :"1"(addr) \
      :);

static inline uint8_t pgm_read_byte_inlined(const void* addr) {
  register uint32_t res;
  pgm_read_with_offset(addr, res);
  return (uint8_t) res;     /* This masks the lower byte from the returned word */
}

/* Although this says "word", it's actually 16 bit, i.e. half word on Xtensa */
static inline uint16_t pgm_read_word_inlined(const void* addr) {
  register uint32_t res;
  pgm_read_with_offset(addr, res);
  return (uint16_t) res;    /* This masks the lower half-word from the returned word */
}

// Make sure, that libraries checking existence of this macro are not failing
#define pgm_read_byte(addr) pgm_read_byte_inlined(addr)
#define pgm_read_word(addr) pgm_read_word_inlined(addr)

#else //__ets__
#define pgm_read_byte(addr)     (*reinterpret_cast<const uint8_t*>(addr))
#define pgm_read_word(addr)     (*reinterpret_cast<const uint16_t*>(addr))
#endif //__ets__

#define pgm_read_dword(addr) 		(*reinterpret_cast<const uint32_t*>(addr))
#define pgm_read_float(addr) 		(*reinterpret_cast<const float*>(addr))
#define pgm_read_ptr(addr) 		(*reinterpret_cast<const void* const *>(addr))

#define pgm_read_byte_near(addr) 	pgm_read_byte(addr)
#define pgm_read_word_near(addr) 	pgm_read_word(addr)
#define pgm_read_dword_near(addr) 	pgm_read_dword(addr)
#define pgm_read_float_near(addr)	pgm_read_float(addr)
#define pgm_read_ptr_near(addr) 	pgm_read_ptr(addr)
#define pgm_read_byte_far(addr) 	pgm_read_byte(addr)
#define pgm_read_word_far(addr) 	pgm_read_word(addr)
#define pgm_read_dword_far(addr) 	pgm_read_dword(addr)
#define pgm_read_float_far(addr) 	pgm_read_float(addr)
#define pgm_read_ptr_far(addr)		pgm_read_ptr(addr)

#ifdef __cplusplus
}
#endif

#endif //__PGMSPACE_H_