Re: [PATCH v2 07/74] semihosting: Split out guestfd.c

[Peter Maydell]

On Tue, 3 May 2022 at 21:02, Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> In arm-compat-semi.c, we have more advanced treatment of
> guest file descriptors than we do in other implementations.
> Split out GuestFD and related functions to a new file so
> that they can be shared.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>  configs/targets/aarch64-linux-user.mak    |   1 +
>  configs/targets/aarch64_be-linux-user.mak |   1 +
>  configs/targets/arm-linux-user.mak        |   1 +
>  configs/targets/armeb-linux-user.mak      |   1 +
>  configs/targets/riscv32-linux-user.mak    |   1 +
>  configs/targets/riscv64-linux-user.mak    |   1 +
>  include/semihosting/guestfd.h             |  40 +++++++
>  semihosting/arm-compat-semi.c             | 125 +---------------------
>  semihosting/guestfd.c                     | 116 ++++++++++++++++++++
>  semihosting/meson.build                   |   4 +
>  10 files changed, 168 insertions(+), 123 deletions(-)
>  create mode 100644 include/semihosting/guestfd.h
>  create mode 100644 semihosting/guestfd.c
>
> diff --git a/configs/targets/aarch64-linux-user.mak 
> b/configs/targets/aarch64-linux-user.mak
> index d0c603c54e..db552f1839 100644
> --- a/configs/targets/aarch64-linux-user.mak
> +++ b/configs/targets/aarch64-linux-user.mak
> @@ -2,4 +2,5 @@ TARGET_ARCH=aarch64
>  TARGET_BASE_ARCH=arm
>  TARGET_XML_FILES= gdb-xml/aarch64-core.xml gdb-xml/aarch64-fpu.xml
>  TARGET_HAS_BFLT=y
> +CONFIG_SEMIHOSTING=y
>  CONFIG_ARM_COMPATIBLE_SEMIHOSTING=y

Is it not possible to make CONFIG_ARM_COMPATIBLE_SEMIHOSTING=y
imply CONFIG_SEMIHOSTING=y somehow?


> --- /dev/null
> +++ b/include/semihosting/guestfd.h
> @@ -0,0 +1,40 @@
> +/*
> + * Hosted file support for semihosting syscalls.
> + *
> + * Copyright (c) 2005, 2007 CodeSourcery.
> + * Copyright (c) 2019 Linaro
> + * Copyright © 2020 by Keith Packard <keithp@keithp.com>
> + *
> + * SPDX-License-Identifier: GPL-2.0-or-later
> + */
> +
> +#ifndef SEMIHOSTING_GUESTFD_H
> +#define SEMIHOSTING_GUESTFD_H
> +
> +typedef enum GuestFDType {
> +    GuestFDUnused = 0,
> +    GuestFDHost = 1,
> +    GuestFDGDB = 2,
> +    GuestFDFeatureFile = 3,
> +} GuestFDType;
> +
> +/*
> + * Guest file descriptors are integer indexes into an array of
> + * these structures (we will dynamically resize as necessary).
> + */
> +typedef struct GuestFD {
> +    GuestFDType type;
> +    union {
> +        int hostfd;
> +        unsigned featurefile_offset;
> +    };
> +} GuestFD;
> +
> +int alloc_guestfd(void);
> +void dealloc_guestfd(int guestfd);
> +GuestFD *get_guestfd(int guestfd);
> +
> +void associate_guestfd(int guestfd, int hostfd);
> +void init_featurefile_guestfd(int guestfd);

If these are moving from being static functions local to a file
to being global, they should get kerneldoc style doc-comments here in
the header file.

thanks
-- PMM