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Date: Fri, 18 Feb 2011 17:29:16 +0100
From: Christophe Lyon <christophe.lyon@st.com>
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Subject: Re: [Qemu-devel] [PATCH] target-arm: return the right exit code when
	using semi-hosting.
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To: Peter Maydell <peter.maydell@linaro.org>
Cc: "qemu-devel@nongnu.org" <qemu-devel@nongnu.org>

On 18.02.2011 17:13, Peter Maydell wrote:
> 
> I'm afraid you've just run into the limitations of semihosting
> as an API again: it doesn't provide a way for programs to pass
Indeed.

> out an exit code, and trying to shoehorn back doors for this
> into qemu just results in ugly code in qemu. The qemu
> implementation of semihosting should implement the semihosting
> API, not semihosting with weird undocumented extras.

Well, exit() is documented in the C ISO standard, so using its argument as exit code is doing what the user expects.
 
> If you care about this sort of thing then linux-user mode is
> probably a better approach, as that is actually designed for
> a unixish program to run as-if-natively.

We are using qemu to execute programs compiled in bare machine mode (eg with arm-none-eabi-gcc as opposed to arm-none-linux-gnueabi-gcc), where semihosting is used to communicate with the host environment. And we lack support for exit code.

Christophe.