include/semihosting/guestfd.h

   1 /*
   2  * Hosted file support for semihosting syscalls.
   3  *
   4  * Copyright (c) 2005, 2007 CodeSourcery.
   5  * Copyright (c) 2019 Linaro
   6  * Copyright © 2020 by Keith Packard <keithp@keithp.com>
   7  *
   8  * SPDX-License-Identifier: GPL-2.0-or-later
   9  */
  10
  11 #ifndef SEMIHOSTING_GUESTFD_H
  12 #define SEMIHOSTING_GUESTFD_H
  13
  14 typedef enum GuestFDType {
  15     GuestFDUnused = 0,
  16     GuestFDHost,
  17     GuestFDGDB,
  18     GuestFDStatic,
  19     GuestFDConsole,
  20 } GuestFDType;
  21
  22 /*
  23  * Guest file descriptors are integer indexes into an array of
  24  * these structures (we will dynamically resize as necessary).
  25  */
  26 typedef struct GuestFD {
  27     GuestFDType type;
  28     union {
  29         int hostfd;
  30         struct {
  31             const uint8_t *data;
  32             size_t len;
  33             size_t off;
  34         } staticfile;
  35     };
  36 } GuestFD;
  37
  38 /**
  39  * alloc_guestfd:
  40  *
  41  * Allocate an unused GuestFD index.  The associated guestfd index
  42  * will still be GuestFDUnused until it is initialized.
  43  */
  44 int alloc_guestfd(void);
  45
  46 /**
  47  * dealloc_guestfd:
  48  * @guestfd: GuestFD index
  49  *
  50  * Deallocate a GuestFD index.  The associated GuestFD structure
  51  * will be recycled for a subsequent allocation.
  52  */
  53 void dealloc_guestfd(int guestfd);
  54
  55 /**
  56  * get_guestfd:
  57  * @guestfd: GuestFD index
  58  *
  59  * Return the GuestFD structure associated with an initialized @guestfd,
  60  * or NULL if it has not been allocated, or hasn't been initialized.
  61  */
  62 GuestFD *get_guestfd(int guestfd);
  63
  64 /**
  65  * associate_guestfd:
  66  * @guestfd: GuestFD index
  67  * @hostfd: host file descriptor
  68  *
  69  * Initialize the GuestFD for @guestfd to GuestFDHost using @hostfd.
  70  */
  71 void associate_guestfd(int guestfd, int hostfd);
  72
  73 /**
  74  * staticfile_guestfd:
  75  * @guestfd: GuestFD index
  76  * @data: data to be read
  77  * @len: length of @data
  78  *
  79  * Initialize the GuestFD for @guestfd to GuestFDStatic.
  80  * The @len bytes at @data will be returned to the guest on reads.
  81  */
  82 void staticfile_guestfd(int guestfd, const uint8_t *data, size_t len);
  83
  84 #endif /* SEMIHOSTING_GUESTFD_H */