Error Code Reference¶

This page documents all error codes used throughout the Nexus platform. All HAL and framework functions return nx_status_t to indicate success or failure.

Error Code Categories¶

Error codes are organized into categories for easy identification:

0: Success
1-19: General errors
20-39: State errors
40-59: Resource errors
60-79: Timeout errors
80-99: IO errors
100-119: DMA errors
120-139: Data errors
140-159: Permission errors

Success Code¶

Code	Value	Description
`NX_OK`	0	Operation completed successfully

General Errors (1-19)¶

Code	Value	Description
`NX_ERR_GENERIC`	1	Generic error (use more specific codes when possible)
`NX_ERR_INVALID_PARAM`	2	Invalid parameter passed to function
`NX_ERR_NULL_PTR`	3	Null pointer passed where valid pointer required
`NX_ERR_NOT_SUPPORTED`	4	Operation not supported by this device/platform
`NX_ERR_NOT_FOUND`	5	Requested item not found
`NX_ERR_INVALID_SIZE`	6	Invalid size parameter

State Errors (20-39)¶

Code	Value	Description
`NX_ERR_NOT_INIT`	20	Device or module not initialized
`NX_ERR_ALREADY_INIT`	21	Device or module already initialized
`NX_ERR_INVALID_STATE`	22	Operation invalid in current state
`NX_ERR_BUSY`	23	Device is busy with another operation
`NX_ERR_SUSPENDED`	24	Device is in suspended state

Resource Errors (40-59)¶

Code	Value	Description
`NX_ERR_NO_MEMORY`	40	Out of memory
`NX_ERR_NO_RESOURCE`	41	Required resource unavailable
`NX_ERR_RESOURCE_BUSY`	42	Resource is busy
`NX_ERR_LOCKED`	43	Resource is locked
`NX_ERR_FULL`	44	Buffer or queue is full
`NX_ERR_EMPTY`	45	Buffer or queue is empty

Timeout Errors (60-79)¶

Code	Value	Description
`NX_ERR_TIMEOUT`	60	Operation timed out
`NX_ERR_WOULD_BLOCK`	61	Operation would block (non-blocking mode)

IO Errors (80-99)¶

Code	Value	Description
`NX_ERR_IO`	80	Generic IO error
`NX_ERR_OVERRUN`	81	Buffer overrun occurred
`NX_ERR_UNDERRUN`	82	Buffer underrun occurred
`NX_ERR_PARITY`	83	Parity error detected
`NX_ERR_FRAMING`	84	Framing error detected
`NX_ERR_NOISE`	85	Noise error detected
`NX_ERR_NACK`	86	NACK received (I2C communication)
`NX_ERR_BUS`	87	Bus error occurred
`NX_ERR_ARBITRATION`	88	Arbitration lost (I2C/CAN)

DMA Errors (100-119)¶

Code	Value	Description
`NX_ERR_DMA`	100	Generic DMA error
`NX_ERR_DMA_TRANSFER`	101	DMA transfer error
`NX_ERR_DMA_CONFIG`	102	DMA configuration error

Data Errors (120-139)¶

Code	Value	Description
`NX_ERR_NO_DATA`	120	No data available
`NX_ERR_DATA_SIZE`	121	Data size error
`NX_ERR_CRC`	122	CRC check failed
`NX_ERR_CHECKSUM`	123	Checksum verification failed

Permission Errors (140-159)¶

Code	Value	Description
`NX_ERR_PERMISSION`	140	Permission denied
`NX_ERR_READ_ONLY`	141	Attempted write to read-only resource

Error Handling Utilities¶

Checking Status¶

#include "hal/nx_status.h"

nx_status_t status = some_function();

/* Check if operation succeeded */
if (NX_IS_OK(status)) {
    /* Success */
}

/* Check if operation failed */
if (NX_IS_ERROR(status)) {
    /* Handle error */
}

Error Propagation¶

#include "hal/nx_status.h"

nx_status_t my_function(void) {
    nx_status_t status;

    /* Return immediately if error occurs */
    status = some_operation();
    NX_RETURN_IF_ERROR(status);

    /* Check for NULL pointer */
    void* ptr = get_pointer();
    NX_RETURN_IF_NULL(ptr);

    /* Continue with normal flow */
    return NX_OK;
}

Error Cleanup¶

#include "hal/nx_status.h"

nx_status_t my_function(void) {
    nx_status_t result = NX_OK;
    void* resource = NULL;

    /* Allocate resource */
    resource = allocate();
    if (!resource) {
        result = NX_ERR_NO_MEMORY;
        goto cleanup;
    }

    /* Use resource */
    NX_GOTO_IF_ERROR(operation(resource), cleanup, result);

cleanup:
    if (resource) {
        free(resource);
    }
    return result;
}

Error Callbacks¶

#include "hal/nx_status.h"

/* Error callback function */
void error_handler(void* user_data, nx_status_t status,
                  const char* module, const char* msg) {
    /* Log error */
    LOG_ERROR(module, "Error %d: %s", status, msg);
}

/* Register error callback */
nx_set_error_callback(error_handler, NULL);

/* Errors will now be reported through callback */

Converting to String¶

#include "hal/nx_status.h"

nx_status_t status = some_function();
if (NX_IS_ERROR(status)) {
    const char* error_str = nx_status_to_string(status);
    printf("Error: %s\n", error_str);
}

Best Practices¶

Always check return values: Never ignore status codes from HAL functions
Use specific error codes: Prefer specific codes over NX_ERR_GENERIC
Propagate errors: Use NX_RETURN_IF_ERROR to propagate errors up the call stack
Clean up resources: Use NX_GOTO_IF_ERROR for proper cleanup on error
Log errors: Use error callbacks or logging to track errors in production
Document error conditions: Document which errors each function can return

Common Error Scenarios¶

Initialization Errors¶

/* Device not initialized */
status = device_operation();
if (status == NX_ERR_NOT_INIT) {
    /* Initialize device first */
    device_init();
}

Timeout Handling¶

/* Operation with timeout */
status = device_read(buffer, size, 1000);
if (status == NX_ERR_TIMEOUT) {
    /* Retry or handle timeout */
}

Resource Management¶

/* Check for resource availability */
status = allocate_resource();
if (status == NX_ERR_NO_MEMORY) {
    /* Free some memory and retry */
}

Communication Errors¶

/* I2C communication */
status = i2c_write(addr, data, len);
if (status == NX_ERR_NACK) {
    /* Device not responding */
} else if (status == NX_ERR_ARBITRATION) {
    /* Bus arbitration lost, retry */
}

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