I write a bootloader for an AVR XMega Microcontroller and the bootloader got configured by a configuration file:
Config_Bootloader.h
#ifndef CONFIG_BOOTLOADER_H_
#define CONFIG_BOOTLOADER_H_
#include <avr/io.h>
#define BOOTLOADER_INTERFACE &USARTE0
#define BOOTLOADER_BAUD 115200
#define BOOTLOADER_TX 3
#endif /* CONFIG_BOOTLOADER_H_ */
This configuration file is should be preprocessed by another include file to get some register values etc.
Bootloader_Preprocessing.h
#ifndef BOOTLOADER_PREPROCESSING_H_
#define BOOTLOADER_PREPROCESSING_H_
#include <avr/io.h>
#ifdef USARTE0
#if(BOOTLOADER_INTERFACE == &USARTE0)
#define BOOTLOADER_PORT &PORTE
#else
#error "Invalid bootloader interface!"
#endif
#endif
#if(BOOTLOADER_BAUD == 9600)
#define BOOTLOADER_BRREG_VALUE 12
#define BOOTLOADER_SCALE_VALUE 0
#elif(BOOTLOADER_BAUD == 19200)
#define BOOTLOADER_BRREG_VALUE 11
#define BOOTLOADER_SCALE_VALUE -1
#elif(BOOTLOADER_BAUD == 38400)
#define BOOTLOADER_BRREG_VALUE 9
#define BOOTLOADER_SCALE_VALUE -2
#elif(BOOTLOADER_BAUD == 57600)
#define BOOTLOADER_BRREG_VALUE 75
#define BOOTLOADER_SCALE_VALUE -6
#elif(BOOTLOADER_BAUD == 115200)
#define BOOTLOADER_BRREG_VALUE 11
#define BOOTLOADER_SCALE_VALUE -7
#else
#error "Invalid baud rate for bootloader!"
#endif
#endif /* BOOTLOADER_PREPROCESSING_H_ */
I include both files into my Bootloader.h
#ifndef BOOTLOADER_H_
#define BOOTLOADER_H_
#include "Config_Bootloader.h"
#include "Bootloader_Preprocessing.h"
#endif /* BOOTLOADER_H_ */
And I get this errors and warnings:
> #define BOOTLOADER_INTERFACE &USARTE0
operator '&' has no left operand
> #if(BOOTLOADER_INTERFACE == &USARTE0)
in expansion of macro 'BOOTLOADER_INTERFACE'
#error "Invalid bootloader interface!"
So why does the compare of the address doesn´t work?
There is no such thing as an "address" in the preprocessor, therefore they cannot be compared in an #if preprocessor instruction.
See the GCC docs for #IF for details on what it can and can't do. Consult the documentation for the preprocessor you are using, additional/different restrictions may apply (you tagged this as AVR).
It seems that your preprocessor concluded that the operator & has to be the bitwise operator &, which is a binary operator and therefore requires a left operand.
Okay, I have a solution after struggeling with the C preprocessor.
I define the symbol BOOTLOADER_INTERFACE=E,0 in my config and process the input:
#define CATENATE(Prefix, Name) Prefix##Name
#define FIRST_ARG(A, B) A
#define SECOND_ARG(A, B) B
#define MAKE_USART_NAME(Uart) CATENATE(USART, Uart)
#define MAKE_PORT_NAME(Port) CATENATE(PORT, Port)
#define USART_NAME(Name) MAKE_USART_NAME(CATENATE(Name))
#define PORT_NAME(Name) MAKE_PORT_NAME(FIRST_ARG(Name))
The result is the address of the PORT- and USART-Structure, depending on the given USART interface.
Related
My machine has CRTSCTS #defined inside a #ifdef __USE_MISC which stops it being available to C programs which I compile.
/usr/include/x86_64-linux-gnu/bits/termios.h:
...
#define B4000000 0010017
#define __MAX_BAUD B4000000
#ifdef __USE_MISC
# define CIBAUD 002003600000 /* input baud rate (not used) */
# define CMSPAR 010000000000 /* mark or space (stick) parity */
# define CRTSCTS 020000000000 /* flow control */
#endif
/* c_lflag bits */
#define ISIG 0000001
#define ICANON 0000002
...
How do I get access to CRTSCTS without just hacking the value 020000000000 into my program?
I already #include <termios.h> and many other headers.
I am also using:
#define __USE_POSIX199309
#define _POSIX_C_SOURCE 199309L
#include <time.h> /* nanosleep needs lines above */
The __USE_MISC macro is an internal definition that, though I suppose you could define this yourself, it's better to find the proper feature-test macro that enables it.
On my CentOS 7 system, /usr/include/features.h has a whole range of these kinds of macros, and it appears that __USE_MISC is enabled by _BSD_SOURCE or _SVID_SOURCE; it's not clear which one is compatible with other things you're going to need.
... // features.h
#if defined _BSD_SOURCE || defined _SVID_SOURCE
# define __USE_MISC 1
#endif
Try #define _BSD_SOURCE at the top of your program - before all the includes - and see how it goes.
Ref: http://man7.org/linux/man-pages/man7/feature_test_macros.7.html
I'm trying to write definitions for AVR C code so that i can access pins by simmple macro like
STATUS_LED_OUT =1;
in GENET_HW_DEF.h file, included to main C file. You can reproduce this bug by including this file into any C project.
I'm using avr studio 6.2 and 7 - both give the same result. I cannot compile getting werid macro unfold message like below. (CPU ATMega1284p)
D:\_SVN\Compass\AVR\Compass_IO_proto\Compass IO_proto\GENET_HW_DEF.h(19,49): error: expected ')' before '&' token
#define REGISTER_BIT(rg,bt) ((volatile _io_reg*)&rg)->bit##bt
^
D:\_SVN\Compass\AVR\Compass_IO_proto\Compass IO_proto\GENET_HW_DEF.h(42,25): info: in expansion of macro 'REGISTER_BIT'
#define STATUS_LED_OUT REGISTER_BIT(PORTB,7)
^
D:\_SVN\Compass\AVR\Compass_IO_proto\Compass IO_proto\GENET_HW_DEF.h(46,2): info: in expansion of macro 'STATUS_LED_OUT'
STATUS_LED_OUT=1;
^
Interesting enough, copied to fresh project with just only one or two declarations compiles fine, until one makes any changes in the declarations - like adding another macro reference. Then it becomes stuck again.
Also - if i comment all macro usages like
STATUS_LED_DIR=1;
STATUS_LED_OUT=1;
then I'm able to compile project and then after uncommenting usage lines it still compiles fine.. untill clean is executed. I'm probably messing with macro quirks but I have no idea where.
typedef struct
{
unsigned int bit0:1;
unsigned int bit1:1;
unsigned int bit2:1;
unsigned int bit3:1;
unsigned int bit4:1;
unsigned int bit5:1;
unsigned int bit6:1;
unsigned int bit7:1;
} _io_reg;
#define REGISTER_BIT(rg,bt) ((volatile _io_reg*)&rg)->bit##bt
#ifndef GENET_HW_DEF
#define GENET_HW_DEF
// define functionalities and flags - comment/uncomment apropriate lines
#define GENET_USART_0 256
#define GENET_USART_1 256
#define F_CPU 20000000UL
#define STATUS_LED 7
#define ERROR_LED 4
#define ADC_GLOBAL_ENABLE A
#define ADC_CHANNEL_0 0
#define ADC_CHANNEL_1 4
#define ADC_CHANNEL_2 2
#define ADC_CHANNEL_3 3
#define ADC_CHANNEL_4 1
#define ADC_CHANNEL_5 5
#define ADC_CHANNEL_6 6
#define ADC_CHANNEL_7 7
// actual definitions and initialization
#ifdef STATUS_LED
#define STATUS_LED_OUT REGISTER_BIT(PORTB,STATUS_LED)
#define STATUS_LED_DIR REGISTER_BIT(DDRB,STATUS_LED)
#define STATUS_LED_PIN REGISTER_BIT(PINB,STATUS_LED)
STATUS_LED_DIR=1;
STATUS_LED_OUT=1;
#endif
#ifdef ERROR_LED
#define ERROR_LED_OUT REGISTER_BIT(PORTC,ERROR_LED)
#define ERROR_LED_DIR REGISTER_BIT(DDRC,ERROR_LED)
ERROR_LED_DIR=1;
ERROR_LED_OUT=1;
#endif
#ifdef GENET_USART_0
#define USART0_ENABLED
#define UART_RX0_BUFFER_SIZE GENET_USART_0
#define UART_TX0_BUFFER_SIZE GENET_USART_0
#endif
#ifdef GENET_USART_1
#define USART1_ENABLED
#define UART_RX1_BUFFER_SIZE GENET_USART_1
#define UART_TX1_BUFFER_SIZE GENET_USART_1
#endif
#endif
I reproduced your problem.
You cannot call STATUS_LED_DIR=1; outside code execution flow. This must be inside a function (for example main()).
Now you will end with other compilation errors but this was the main mistake.
Second correction, you need 2 level for concatenation
#define CONCAT(bt) bit##bt
#define REGISTER_BIT(rg,bt) ((volatile _io_reg*)&rg)->CONCAT(bt)
Is there some functions in c which behaves like scanf (taking inputs from the keyboard) while being able to move the cursor in the input by pressing the arrow keys, like in a terminal ?
There are no function in C standard to do that.
You can look at ncurses
In addition to previous suggestions, if you want to do a little work you can "roll your own" using the vt100 escape sequences, which most (probably all) terminal programs continue to support. Here's a small sample program,
#include <stdio.h>
#include <string.h>
#include "vt100.h"
int main ( int argc, char *argv[] )
{
char cupstr[99];
char reply[99];
strcpy(cupstr,_cup(12,25));
printf("%sEnter Data ---> ",cupstr);
fgets(reply,88,stdin);
strcpy(cupstr,_cup(13,25));
printf("%sEchoed Data --> %s\n",cupstr,reply);
}
And the big part is that vt100.h containing all the escape sequences,
/* ------------------------------------------------------------------------- *
VT100.H (c)1989-1999, John Forkosh Associates VT-100 Graphics
* ------------------------------------------------------------------------- */
#define bel printf("\007")
#define esc printf("\033")
#define csi printf("\033[")
#define lscreen printf("\033[?5h")
#define dscreen printf("\033[?5l")
#define rev_vid printf("\033[7m")
#define blink printf("\033[5m")
#define under printf("\033[4m")
#define bold printf("\033[1m")
#define norm_vid printf("\033[0m")
#define wide_vid printf("\033#6")
#define high_vid2 printf("\033#4")
#define high_vid1 printf("\033#3")
#define graphic printf("\033(0")
#define no_graph printf("\033(B")
#define no_window printf("\033[1;24r")
#define no_att printf("\033[0;22;24;25;27m")
#define cup(row,col) printf("\033[%d;%dH",(row),(col))
#define stbm(top,bot) printf("\033[%d;%dr",(top),(bot))
#define ri printf("\033M")
#define el printf("\033[K")
#define ed0 printf("\033[0J")
#define bar graphic;printf("x");no_graph
#define wipe(row,col) cup(row,col);printf("\033[J")
#define clr wipe(0,0);norm_vid
/* ------------------------------------------------------------------------- *
String equivalents ... Note: _cup() and _stbm() only accept literal args.
* ------------------------------------------------------------------------- */
#define _bel "\007"
#define _esc "\033"
#define _csi "\033["
#define _lscreen "\033[?5h"
#define _dscreen "\033[?5l"
#define _rev_vid "\033[7m"
#define _blink "\033[5m"
#define _under "\033[4m"
#define _bold "\033[1m"
#define _norm_vid "\033[0m"
#define _wide_vid "\033#6"
#define _high_vid2 "\033#4"
#define _high_vid1 "\033#3"
#define _graphic "\033(0"
#define _no_graph "\033(B"
#define _no_window "\033[1;24r"
#define _no_att "\033[0;22;24;25;27m"
#define _cup(row,col) "\033[" #row ";" #col "\110"
#define _stbm(top,bot) "\033[" #top ";" #bot "\162"
#define _ri "\033M"
#define _el "\033[K"
#define _ed0 "\033[0J"
#define _bar "\033(0x\033(B"
#define _wipe_clr "\033[0;0H\033[2J"
#define _clr "\033[0;0H\033[2J\033(B\033[0m\033[1;24r"
/* ------------------------------------------------------------------------- */
These escape sequences let you program all the stuff that used to look so cool on vt100's, vt220's, etc, a long, long time ago (but right here in this galaxy).
I'm trying to use multiple macros in the definition of another macro, but seem to have problems concatenating them together. Here's a very simplified version of what I'm trying to do:
#include <stdio.h>
#define PICK_SET_A
#ifdef PICK_SET_A
#define SET A
#endif
#ifdef PICK_SET_B
#define SET B
#endif
#define ENABLE_VAR_1_A 1
#define ENABLE_VAR_2_A 1
#define ENABLE_VAR_1_B 0
#define ENABLE_VAR_2_B 0
#define MACRO_RESOLVE(var,set) ENABLE_VAR_##var##_##set
#define ENABLE_VAR_1 MACRO_RESOLVE(1, SET)
#define ENABLE_VAR_2 MACRO_RESOLVE(2, SET)
int main(int argc, char **argv) {
fprintf(stdout, "VALUE: %d\n", ENABLE_VAR_1);
return 0;
}
I would expect the result to be 0.
However, I'm getting compile errors because the MACRO_RESOLVE macro isn't resolving the way I expect it to:
$ gcc -o asdf asdf.c
asdf.c:25:36: error: use of undeclared identifier 'ENABLE_VAR_1_SET'
fprintf(stdout, "VALUE: %d\n", ENABLE_VAR_1);
^
asdf.c:20:26: note: expanded from macro 'ENABLE_VAR_1'
#define ENABLE_VAR_1 MACRO_RESOLVE(1, SET)
^
asdf.c:18:32: note: expanded from macro 'MACRO_RESOLVE'
#define MACRO_RESOLVE(var,set) ENABLE_VAR_##var##_##set
^
<scratch space>:229:1: note: expanded from here
ENABLE_VAR_1_SET
^
1 error generated.
So it looks like SET isn't getting expanded when I define ENABLE_VAR_1.
Since you are trying to build a macro name, you need to do enough intermediate expansions along the way for all tokens to expand. See it live here.
#include <stdio.h>
#define PICK_SET_A
#ifdef PICK_SET_A
#define SET A
#endif
#ifdef PICK_SET_B
#define SET B
#endif
#define ENABLE_VAR_1_A 1
#define ENABLE_VAR_2_A 1
#define ENABLE_VAR_1_B 0
#define ENABLE_VAR_2_B 0
#define MACRO_RESOLVE__(M) M
#define MACRO_RESOLVE_(V, S) MACRO_RESOLVE__(ENABLE_VAR_ ## V ##_## S)
#define MACRO_RESOLVE(var,set) MACRO_RESOLVE_(var, set)
#define ENABLE_VAR_1 MACRO_RESOLVE(1, SET)
#define ENABLE_VAR_2 MACRO_RESOLVE(2, SET)
int main(int argc, char **argv) {
fprintf(stdout, "VALUE: %d\n", ENABLE_VAR_1);
return 0;
}
This question already has answers here:
What are the applications of the ## preprocessor operator and gotchas to consider?
(13 answers)
Closed 7 years ago.
I have a set of target macros for which I want to generate aliases based on a choosing macro, like so:
Choosing macro:
#define I2C_MODULE 1
Alias macros (conceptual form):
#define I2C_MODULE_BASE I2C<Value of I2C_MODULE>_BASE
#define I2C_MODULE_NVIC INT_I2C<Value of I2C_MODULE>
Target macros (from an external file out of my control):
#define INT_I2C0 24
#define INT_I2C1 53
...
#define I2C0_BASE 0x40020000
#define I2C1_BASE 0x40021000
...
I wanted to have the preprocessor generate the alias macros I2C_MODULE_BASE and I2C_MODULE_NVIC based on the
choosing macro I2C_MODULE, but after much reading Q1, P1 and many other references I lost track of, I ended up hard-coding their values. Below I show my current working definitions, and then my last failed attempts at generating the macros:
What works:
#define I2C_MODULE 1
#define I2C_MODULE_BASE I2C1_BASE
#define I2C_MODULE_NVIC INT_I2C1
what did not work:
#define I2C_MODULE 1
#define STR_HELPER(x) #x
#define STR(x) STR_HELPER(x)
/* Attempt 1 */
#define I2C_MODULE_BASE "I2C" STR(I2C_MODULE) "_BASE"
#define I2C_MODULE_NVIC "INT_I2C" STR(I2C_MODULE)
/* Attempt 2 */
#define _I2C_MODULE_BASE "I2C" STR(I2C_MODULE) "_BASE"
#define _I2C_MODULE_NVIC "INT_I2C" STR(I2C_MODULE)
#define I2C_MODULE_BASE _I2C_MODULE_BASE
#define I2C_MODULE_NVIC _I2C_MODULE_NVIC
EDIT: I expanded upon the accepted answer to get to where I wanted, as follows:
#define PASTE2(a, b) a ## b
#define PASTE3(a, b, c) a ## b ## c
#define _I2C_MODULE_BASE(x) PASTE3(I2C, x, _BASE)
#define _I2C_MODULE_NVIC(x) PASTE2(INT_I2C, x)
#define I2C_MODULE_BASE _I2C_MODULE_BASE(I2C_MODULE)
#define I2C_MODULE_NVIC _I2C_MODULE_NVIC(I2C_MODULE)
This seems to work:
#define I2C_MODULE 1
//Alias macros (conceptual form):
//#define I2C_MODULE_BASE I2C<Value of I2C_MODULE>_BASE
//#define I2C_MODULE_NVIC INT_I2C<Value of I2C_MODULE>
//Target macros (from an external file out of my control):
#define INT_I2C0 24
#define INT_I2C1 53
#define I2C0_BASE 0x40020000
#define I2C1_BASE 0x40021000
#define PASTE2(a, b) a ## b
#define PASTE3(a, b, c) a ## b ## c
#define I2C_MODULE_BASE(x) PASTE3(I2C, x, _BASE)
#define I2C_MODULE_NVIC(x) PASTE2(INT_I2C, x)
extern int i2c_module_base = I2C_MODULE_BASE(I2C_MODULE);
extern int i2c_module_nvic = I2C_MODULE_NVIC(I2C_MODULE);
extern int i2c_module_base_0 = I2C_MODULE_BASE(0);
extern int i2c_module_nvic_0 = I2C_MODULE_NVIC(0);
extern int i2c_module_base_1 = I2C_MODULE_BASE(1);
extern int i2c_module_nvic_1 = I2C_MODULE_NVIC(1);
Sample output (from cpp):
# 1 "xx.c"
# 1 "<built-in>"
# 1 "<command-line>"
# 1 "xx.c"
# 21 "xx.c"
extern int i2c_module_base = 0x40021000;
extern int i2c_module_nvic = 53;
extern int i2c_module_base_0 = 0x40020000;
extern int i2c_module_nvic_0 = 24;
extern int i2c_module_base_1 = 0x40021000;
extern int i2c_module_nvic_1 = 53;
It is closely based on my answer to C preprocessor and token concatenation.
There are undoubtedly other ways that the I2C_MODULE_BASE and I2C_MODULE_NVIC macros could be written, but the key points are:
Using the ## token pasting operator (not the # stringifying operator).
Using two levels of macro (for example, I2C_MODULE_BASE and PASTE3).
I suspect that you are writing a I2C driver which can generically handle multiple I2C hardware peripherals in the same micro-controller without rewriting all the same code multiple times.
In that case, what you are really looking for probably is something like this:
#define I2C1 ((volatile uint8_t*)0x12345678) // address of first hw register for I2C1
#define I2C2 ((volatile uint8_t*)0x55555555) // address of first hw register for I2C2
/* map all registers used for I2C, they will have same register layout for every
peripheral no matter which one: */
#define I2C_CONTROL(base) (*(base + 0))
#define I2C_DATA(base) (*(base + 1))
...
// create some dummy typedef to make your functions look nice:
typedef volatile uint8_t* I2C_t;
// define whatever functions you need in the driver:
void i2c_init (IC2_t bus);
void i2c_send (I2C_t bus, const uint8_t* data, size_t n);
...
// implement functions in a bus-independent way:
void i2c_init (IC2_t bus)
{
I2C_CONTROL(bus) = THIS | THAT; // setup registers
}
// caller code:
i2c_init(I2C1);
i2c_init(I2C2);
...
i2c_send(I2C1, "hello", 5);
i2c_send(I2C2, "world", 5);
Just use #if / #else / #endif
#if (I2C_MODULE == 0)
#define I2C_MODULE_BASE I2C0_BASE
#define I2C_MODULE_NVIC INT_I2C0
#elif (I2C_MODULE == 1)
#define I2C_MODULE_BASE I2C1_BASE
#define I2C_MODULE_NVIC INT_I2C1
#else
#error Unknown configuration
#endif