u-boot/include/semihosting.h

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/* SPDX-License-Identifier: GPL-2.0+ */
/*
* Copyright (C) 2022 Sean Anderson <sean.anderson@seco.com>
*/
#ifndef _SEMIHOSTING_H
#define _SEMIHOSTING_H
/*
* These are the encoded instructions used to indicate a semihosting trap. They
* are named like SMH_ISA_INSN, where ISA is the instruction set (e.g.
* AArch64), and INSN is the mneumonic for the instruction.
*/
#define SMH_A64_HLT 0xD45E0000
#define SMH_A32_SVC 0xEF123456
#define SMH_A32_HLT 0xE10F0070
#define SMH_T32_SVC 0xDFAB
#define SMH_T32_HLT 0xBABC
/**
* smh_trap() - ARCH-specific semihosting call.
*
* Semihosting library/driver can use this function to do the
* actual semihosting calls.
*
* Return: Error code defined by semihosting spec.
*/
long smh_trap(unsigned int sysnum, void *addr);
#if CONFIG_IS_ENABLED(SEMIHOSTING_FALLBACK)
/**
* semihosting_enabled() - Determine whether semihosting is supported
*
* Semihosting-based drivers should call this function before making other
* semihosting calls.
*
* Return: %true if a debugger is attached which supports semihosting, %false
* otherwise
*/
bool semihosting_enabled(void);
/**
* disable_semihosting() - Cause semihosting_enabled() to return false
*
* If U-Boot ever receives an unhandled exception caused by a semihosting trap,
* the trap handler should call this function.
*/
void disable_semihosting(void);
#else
static inline bool semihosting_enabled(void)
{
return CONFIG_IS_ENABLED(SEMIHOSTING);
}
static inline void disable_semihosting(void)
{
}
#endif
/**
* enum smh_open_mode - Numeric file modes for use with smh_open()
* MODE_READ: 'r'
* MODE_BINARY: 'b'
* MODE_PLUS: '+'
* MODE_WRITE: 'w'
* MODE_APPEND: 'a'
*
* These modes represent the mode string used by fopen(3) in a form which can
* be passed to smh_open(). These do NOT correspond directly to %O_RDONLY,
* %O_CREAT, etc; see fopen(3) for details. In particular, @MODE_PLUS
* effectively results in adding %O_RDWR, and @MODE_WRITE will add %O_TRUNC.
* For compatibility, @MODE_BINARY should be added when opening non-text files
* (such as images).
*/
enum smh_open_mode {
MODE_READ = 0x0,
MODE_BINARY = 0x1,
MODE_PLUS = 0x2,
MODE_WRITE = 0x4,
MODE_APPEND = 0x8,
};
/**
* smh_open() - Open a file on the host
* @fname: The name of the file to open
* @mode: The mode to use when opening the file
*
* Return: Either a file descriptor or a negative error on failure
*/
long smh_open(const char *fname, enum smh_open_mode mode);
/**
* smh_read() - Read data from a file
* @fd: A file descriptor returned from smh_open()
* @memp: Pointer to a buffer of memory of at least @len bytes
* @len: The number of bytes to read
*
* Return:
* * The number of bytes read on success, with 0 indicating %EOF
* * A negative error on failure
*/
long smh_read(long fd, void *memp, size_t len);
/**
* smh_write() - Write data to a file
* @fd: A file descriptor returned from smh_open()
* @memp: Pointer to a buffer of memory of at least @len bytes
* @len: The number of bytes to read
* @written: Pointer which will be updated with the actual bytes written
*
* Return: 0 on success or negative error on failure
*/
long smh_write(long fd, const void *memp, size_t len, ulong *written);
/**
* smh_close() - Close an open file
* @fd: A file descriptor returned from smh_open()
*
* Return: 0 on success or negative error on failure
*/
long smh_close(long fd);
/**
* smh_flen() - Get the length of a file
* @fd: A file descriptor returned from smh_open()
*
* Return: The length of the file, in bytes, or a negative error on failure
*/
long smh_flen(long fd);
/**
* smh_seek() - Seek to a position in a file
* @fd: A file descriptor returned from smh_open()
* @pos: The offset (in bytes) to seek to
*
* Return: 0 on success or negative error on failure
*/
long smh_seek(long fd, long pos);
/**
* smh_getc() - Read a character from stdin
*
* Return: The character read, or a negative error on failure
*/
int smh_getc(void);
/**
* smh_putc() - Print a character on stdout
* @ch: The character to print
*/
void smh_putc(char ch);
/**
* smh_write0() - Print a nul-terminated string on stdout
* @s: The string to print
*/
void smh_puts(const char *s);
#endif /* _SEMIHOSTING_H */