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- From: Dan <dgisselq at verizon dot net>
- To: binutils at sourceware dot org
- Date: Tue, 23 Feb 2016 10:50:22 -0500
- Subject: ELF octets_per_byte
- Authentication-results: sourceware.org; auth=none
- Reply-to: dgisselq at ieee dot org
I am in the process of trying to port binutils to a new architecture,
the ZipCPU. (You can find a description of it here:
https://opencores.org/project,zipcpu) One unique +ACI-feature+ACI of this
processor is that the size of the minimum addressable unit is 32-bits.
While binutils has support for an +ACI-octets+AF8-per+AF8-byte+ACI value other than
one, this feature does not appear to be fully supported. Indeed, the
+ACI-bfd/elflink.c+ACI file contains several +ACI-FIXME+ACI lines regarding the
insufficiency of the current support.
All of these can be easily fixed, and I would like to propose a patch
(or series of patches) to do this. The first part of this process will
need to be identifying which ELF variables/values are +ACI-bytes+ACI (units of
the targets address space), and which are +ACI-octets+ACI (8-bit values, units
of the more commonly used address space). Sadly, these units are not
consistent with the meaning of +ACI-bytes+ACI found within the ELF
specification, nor can they be since the ELF specification does not
acknowledge the potential difference between these two.
For the purpose of beginning a discussion, and based upon a reading of
the ELF specification, I propose the following values be in units of
section header size
section header offset
For the most part, these values +ACo-must+ACo be in octets, or it will be
impossible to read and process an ELF file.
I also propose that the following values are in units of target address
ELF header +ACI-entry+ACI address
section header address
Using this definition, applications of +ACI-bfd+AF8-octets+AF8-per+AF8-byte()+ACI can be
applied to convert units from one to the other as necessary.
Comments? Are there any values that I have missed?