linux-kernel - Re: [PATCH] ARM: Fix zImage file size not aligned with CONFIG_EFI

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Message-ID: <20171024090953.GZ20805@n2100.armlinux.org.uk>
Date:   Tue, 24 Oct 2017 10:09:54 +0100
From:   Russell King - ARM Linux <linux@...linux.org.uk>
To:     Ard Biesheuvel <ard.biesheuvel@...aro.org>
Cc:     "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        jeffy <jeffy.chen@...k-chips.com>,
        Ingo Molnar <mingo@...nel.org>,
        "linux-arm-kernel@...ts.infradead.org" 
        <linux-arm-kernel@...ts.infradead.org>,
        Chris Zhong <chris.zhong@...k-chips.com>
Subject: Re: [PATCH] ARM: Fix zImage file size not aligned with
 CONFIG_EFI_STUB enabled

On Tue, Oct 24, 2017 at 09:09:52AM +0100, Ard Biesheuvel wrote:
> The following patch appears to fix the issue as well:
> 
> diff --git a/arch/arm/boot/compressed/vmlinux.lds.S
> b/arch/arm/boot/compressed/vmlinux.lds.S
> index 7a4c59154361..0e0f504e256e 100644
> --- a/arch/arm/boot/compressed/vmlinux.lds.S
> +++ b/arch/arm/boot/compressed/vmlinux.lds.S
> @@ -83,7 +83,9 @@ SECTIONS
>    __pecoff_data_rawsize = . - ADDR(.data);
>  #endif
> 
> -  _edata = .;
> +  .edata (NOLOAD) : {
> +    _edata = .;
> +  }
> 
>    _magic_sig = ZIMAGE_MAGIC(0x016f2818);
>    _magic_start = ZIMAGE_MAGIC(_start);
> 
> because the NOLOAD triggers the linker to emit all PROGBITS sections
> before _edata, including unknown ones.
> 
> E.g., in my binary, it gives me
> 
> 00798020 D __pecoff_data_end
> 00798200 d __ksymtab_sort
> 00798208 B __bss_start
> 00798208 D _edata

The question is: do we want to know when additional sections get
emitted into the binary?

You've already said that for EFI, you need the size of the binary
to be a multiple of 512, so I guess the answer to that is "yes".

-- 
RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
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