Re: [Xen-devel] [PATCH v3 1/9] xen: add a generic way to include binary files as variables

["Jürgen Groß" <jgross@suse.com>]

On 03.02.20 14:39, Jan Beulich wrote:
> On 21.01.2020 09:43, Juergen Gross wrote:
>> --- /dev/null
>> +++ b/xen/tools/binfile
>> @@ -0,0 +1,29 @@
>> +#!/bin/sh
>> +# usage: binfile [-i] <target-src.S> <binary-file> <varname>
>> +# -i     add to .init.rodata (default: .rodata) section
>> +
>> +[ "$1" = "-i" ] && {
>> +    shift
>> +    section=".init"
>> +}
>> +
>> +target=$1
>> +binsource=$2
>> +varname=$3
>> +
>> +cat <<EOF >$target
>> +#include <asm/asm_defns.h>
>> +
>> +        .section $section.rodata, "a", %progbits
>> +
>> +        .global $varname
>> +$varname:
>> +        .incbin "$binsource"
>> +.Lend:
>> +
>> +        .type $varname, %object
>> +        .size $varname, . - $varname
> 
> I'd prefer if you used .Lend here as well.

Okay.

> I wonder whether, right from the beginning, there wouldn't better
> be a way to also request better than byte alignment for such a
> blob.

I can add that. What about "-a <n>" for 2^n alignment?

> 
>> --- a/xen/xsm/flask/Makefile
>> +++ b/xen/xsm/flask/Makefile
>> @@ -30,6 +30,9 @@ $(AV_H_FILES): $(AV_H_DEPEND)
>>   obj-bin-$(CONFIG_XSM_FLASK_POLICY) += flask-policy.o
>>   flask-policy.o: policy.bin
>>   
>> +flask-policy.S: $(XEN_ROOT)/xen/tools/binfile
>> +	$(XEN_ROOT)/xen/tools/binfile -i $@ policy.bin xsm_flask_init_policy
> 
> Doesn't objcopy provide a means to convert a binary blob into
> an ELF object containing the binary data from the input file?
> If so, why involve the assembler and an intermediate file here?

I can see how to add a symbol for that purpose using a dedicated section
for each blob, but how to add the size information of the blob?

In the end I just followed commit 8d5671eb31e4bf for the inclusion of
the blob.


Juergen

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