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  * For ARM semihosting, we have a separate structure for routing
  40  * data for the console which is outside the guest fd address space.
  41  */
  42 extern GuestFD console_in_gf;
  43 extern GuestFD console_out_gf;
  44
  45 /**
  46  * alloc_guestfd:
  47  *
  48  * Allocate an unused GuestFD index.  The associated guestfd index
  49  * will still be GuestFDUnused until it is initialized.
  50  */
  51 int alloc_guestfd(void);
  52
  53 /**
  54  * dealloc_guestfd:
  55  * @guestfd: GuestFD index
  56  *
  57  * Deallocate a GuestFD index.  The associated GuestFD structure
  58  * will be recycled for a subsequent allocation.
  59  */
  60 void dealloc_guestfd(int guestfd);
  61
  62 /**
  63  * get_guestfd:
  64  * @guestfd: GuestFD index
  65  *
  66  * Return the GuestFD structure associated with an initialized @guestfd,
  67  * or NULL if it has not been allocated, or hasn't been initialized.
  68  */
  69 GuestFD *get_guestfd(int guestfd);
  70
  71 /**
  72  * associate_guestfd:
  73  * @guestfd: GuestFD index
  74  * @hostfd: host file descriptor
  75  *
  76  * Initialize the GuestFD for @guestfd to GuestFDHost using @hostfd.
  77  */
  78 void associate_guestfd(int guestfd, int hostfd);
  79
  80 /**
  81  * staticfile_guestfd:
  82  * @guestfd: GuestFD index
  83  * @data: data to be read
  84  * @len: length of @data
  85  *
  86  * Initialize the GuestFD for @guestfd to GuestFDStatic.
  87  * The @len bytes at @data will be returned to the guest on reads.
  88  */
  89 void staticfile_guestfd(int guestfd, const uint8_t *data, size_t len);
  90
  91 #endif /* SEMIHOSTING_GUESTFD_H */