Our Ideas, Thoughts, and News
SiFive — Aug 28, 2017
Last week's blog entry discussed relocations and how they apply to the RISC-V toolchain. This week we'll be delving a bit deeper into the RISC-V linker to discuss linker relaxation, a concept so important it has greatly shaped the design of the RISC-V ISA. Linker relaxation is a mechanism for optimizing programs at link-time, as opposed to traditional program optimization which happens at compile-time. This blog will follow an example linker relaxation through the toolchain, demonstrate an example of how linker relaxations meaningfully improve the performance of a real program and introduce a new RISC-V relocation. We'll shy away from discussing the impact of linker relaxations on the RISC-V ISA, until another blog entry.
SiFive — Aug 24, 2017
As we continue to expand our product offerings to better serve the rapidly growing RISC-V and SiFive community, we are always looking to work with companies (big and small) who share our vision.
SiFive — Aug 21, 2017
Our first stop on our exploration of the RISC-V toolchain will be an overview of ELF relocations and how they are used by the RISC-V toolchain. We'll shy away from discussing linker relaxations and their impact on performance for a follow-up blog post so this doesn't get too long. The example has been carefully constructed to be unrelaxable as to avoid confusion. Additionally we're only going to discuss the relocations used by statically linked executables, avoid discussing position independent executables and forget about thread local storage -- like linker relaxation, all of those warrant a whole post on their own. There will be a lot more to come about relocations in later blog posts.
SiFive — Aug 14, 2017
Before we can board the RISC-V train, we'll have to take a stop
at the metaphorical ticket office: our machine-specific GCC command-line
arguments. These arguments all begin with
-m, and are all specific to
the RISC-V architecture port. In general, we've tried to match existing
conventions for these arguments, but like pretty much everything else
there are enough quirks to warrant a blog post. This blog discusses the
arguments most fundamental to the RISC-V ISA: the
SiFive — Aug 7, 2017
I'm Palmer Dabbelt, a software engineer at SiFive and a maintainer of various RISC-V ports. I've been working with the RISC-V ISA for a few years, and it's finally starting to get ready for prime-time. We're not yet upstream in Linux or glibc, but hopefully by the end of the year we'll have the core set of system software in the relevant upstream repositories -- at which point distributions can begin porting to RISC-V and users can begin using our software. I started working with RISC-V before the user ISA had been finalized (at least v2 of the user ISA, the real one :)) and it's almost a bit scary how real things have gotten over the last few years.