Re: [boot-wrapper PATCH v2 2/9] Add standard headers

[Mark Rutland <mark.rutland@arm.com>]

On Wed, Dec 22, 2021 at 06:16:00PM +0000, Andre Przywara wrote:
> So far we were relying on some standard C headers to be provided by the
> toolchain. This applies for instance to stddef.h and stdint.h.
> As a "bare-metal" application, we should not rely on external headers,
> or even on a toolchain providing them in the first place.
> 
> Define our own version of stddef.h and stdint.h, containing just the
> types that we actually need.

Even a freestanding compiler implementation is required to provide these
headers, and using the compiler versions would avoid unexpected mismatches
(e.g. for builtins). So I don't think the justification as written makes sense.

Is this because the next patch removes the stdinc paths, and so we don't get
the compiler's implementation of these headers?

Thanks,
Mark.

> 
> Signed-off-by: Andre Przywara <andre.przywara@arm.com>
> ---
>  arch/aarch32/include/stdint.h | 19 +++++++++++++++++++
>  arch/aarch64/include/stdint.h | 19 +++++++++++++++++++
>  include/stddef.h              | 15 +++++++++++++++
>  3 files changed, 53 insertions(+)
>  create mode 100644 arch/aarch32/include/stdint.h
>  create mode 100644 arch/aarch64/include/stdint.h
>  create mode 100644 include/stddef.h
> 
> diff --git a/arch/aarch32/include/stdint.h b/arch/aarch32/include/stdint.h
> new file mode 100644
> index 0000000..77546f0
> --- /dev/null
> +++ b/arch/aarch32/include/stdint.h
> @@ -0,0 +1,19 @@
> +/*
> + * arch/aarch32/include/stdint.h
> + *
> + * Copyright (C) 2021 ARM Limited. All rights reserved.
> + *
> + * Use of this source code is governed by a BSD-style license that can be
> + * found in the LICENSE.txt file.
> + */
> +#ifndef STDINT_H__
> +#define STDINT_H__
> +
> +typedef unsigned char		uint8_t;
> +typedef unsigned short int	uint16_t;
> +typedef unsigned int		uint32_t;
> +typedef unsigned long long int	uint64_t;
> +
> +typedef unsigned int		uintptr_t;
> +
> +#endif
> diff --git a/arch/aarch64/include/stdint.h b/arch/aarch64/include/stdint.h
> new file mode 100644
> index 0000000..92c2603
> --- /dev/null
> +++ b/arch/aarch64/include/stdint.h
> @@ -0,0 +1,19 @@
> +/*
> + * arch/aarch64/include/stdint.h
> + *
> + * Copyright (C) 2021 ARM Limited. All rights reserved.
> + *
> + * Use of this source code is governed by a BSD-style license that can be
> + * found in the LICENSE.txt file.
> + */
> +#ifndef STDINT_H__
> +#define STDINT_H__
> +
> +typedef unsigned char		uint8_t;
> +typedef unsigned short int	uint16_t;
> +typedef unsigned int		uint32_t;
> +typedef unsigned long int	uint64_t;
> +
> +typedef unsigned long int	uintptr_t;
> +
> +#endif
> diff --git a/include/stddef.h b/include/stddef.h
> new file mode 100644
> index 0000000..3208b10
> --- /dev/null
> +++ b/include/stddef.h
> @@ -0,0 +1,15 @@
> +/*
> + * include/stddef.h - standard data type definitions
> + *
> + * Copyright (C) 2021 ARM Limited. All rights reserved.
> + *
> + * Use of this source code is governed by a BSD-style license that can be
> + * found in the LICENSE.txt file.
> + */
> +#ifndef STDDEF_H__
> +#define STDDEF_H__
> +
> +typedef unsigned long int	size_t;
> +typedef signed long int		ssize_t;
> +
> +#endif
> -- 
> 2.25.1
> 

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