SEGGER Semihosting

SEGGER Semihosting is a standard for Semihosting, defined by SEGGER and compatible to an older standard defined by ARM.

File structure of reference implementation

The reference implementation is provided as a ZIP file, containing a complete project for SEGGER Embedded Studio. The relevant sources are 3 files which are completely generic, so can be compiled on any system using any C- compiler:

• SEGGER_SEMIHOST.h - Interface definition
• SEGGER_SEMIHOST.c - Implementation of the Semihosting interface functions
• SEGGER_SEMIHOST_Generic.c - Implementation of the SEGGER_SEMIHOST_X_Request routine to call SEGGER_SEMIHOST_DebugHalt

The reference project is available for download here: sources

Interface

The below is an exert from SEGGER_SEMIHOST.h, containg the API of the the SEGGER implementation.

int SEGGER_SEMIHOST_Open        (const char* sFilename, int Mode, int LenFilename);
int SEGGER_SEMIHOST_Close       (int hFile);
int SEGGER_SEMIHOST_WriteC      (char c);
int SEGGER_SEMIHOST_Write0      (const char* s);
int SEGGER_SEMIHOST_Write       (int hFile, const char* pBuffer, int NumBytesToWrite);
int SEGGER_SEMIHOST_Writef      (const char* pFormat, va_list* pArg);
int SEGGER_SEMIHOST_Read        (int hFile, char* pBuffer, int NumBytesToRead);
int SEGGER_SEMIHOST_ReadC       (void);
int SEGGER_SEMIHOST_IsTTY       (int hFile);
int SEGGER_SEMIHOST_Seek        (int hFile, int Pos);
int SEGGER_SEMIHOST_FLen        (int hFile);
int SEGGER_SEMIHOST_TmpName     (char* pBuffer, int hFile, int pNumBytesName);
int SEGGER_SEMIHOST_Remove      (const char* pPath, int NumBytesPath);
int SEGGER_SEMIHOST_Rename      (const char* pFileName, int NumBytesFileName, const char* pNewName, int NumBytesNewName);
int SEGGER_SEMIHOST_Clock       (void);
int SEGGER_SEMIHOST_Time        (void);
int SEGGER_SEMIHOST_System      (const char* pCommand, int NumBytesCommand);
int SEGGER_SEMIHOST_Errno       (void);
int SEGGER_SEMIHOST_GetCmdLine  (char* pBuffer, char** psCmdLine, int* pNumBytesCmdLine);
int SEGGER_SEMIHOST_Elapsed     (unsigned long long* pTicks);
int SEGGER_SEMIHOST_HeapInfo    (char* pDataBlock);
int SEGGER_SEMIHOST_TickFreq    (void);
int SEGGER_SEMIHOST_Exit        (int ExitCode);
int SEGGER_SEMIHOST_IsConnected (void);

int SEGGER_SEMIHOST_X_Request (int Op, SEGGER_SEMIHOST_PARA* pPara);