mirror of
https://github.com/u-boot/u-boot.git
synced 2025-04-18 19:04:38 +00:00
385d69d76b
These functions are intended to support detecting semihosting and falling back gracefully to alternative implementations. The test starts by making semihosting call. SYS_ERRNO is chosen because it should not mutate any state. If this semihosting call results in an exception (rather than being caught by the debugger), then the exception handler should call disable_semihosting() and resume execution after the call. Ideally, this would just be part of semihosting by default, and not a separate config. However, to reduce space ARM SPL doesn't include exception vectors by default. This means we can't detect if a semihosting call failed unless we enable them. To avoid forcing them to be enabled, we use a separate config option. It might also be possible to try and detect whether a debugger has enabled (by reading HDE from DSCR), but I wasn't able to figure out a way to do this from all ELs. This patch just introduces the generic code to handle detection. The next patch will implement it for arm64 (but not arm32). Signed-off-by: Sean Anderson <sean.anderson@seco.com>
138 lines
3.6 KiB
C
138 lines
3.6 KiB
C
/* SPDX-License-Identifier: GPL-2.0+ */
|
|
/*
|
|
* Copyright (C) 2022 Sean Anderson <sean.anderson@seco.com>
|
|
*/
|
|
|
|
#ifndef _SEMIHOSTING_H
|
|
#define _SEMIHOSTING_H
|
|
|
|
#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 */
|