The toolchain can usually generate code for many variants of target architecture and often even different endianness. The libgcc on the other hand is usually compiled for one particular configuration and the functions provided by it may or may not be suited for use in U-Boot.
I agree with this change but is this even true? my toolchain(linaro) has 28 different versions of libgcc.a
Thanks Michael
On Mon, Jun 6, 2016 at 7:35 PM, Simon Glass sjg@chromium.org wrote:
On 4 June 2016 at 02:00, Tom Rini trini@konsulko.com wrote:
On Thu, May 26, 2016 at 06:01:47PM +0200, Marek Vasut wrote:
This patch decouples U-Boot binary from the toolchain on systems where private libgcc is available. Instead of pulling in functions provided by the libgcc from the toolchain, U-Boot will use it's own set of libgcc functions. These functions are usually imported from Linux kernel, which also uses it's own libgcc functions instead of the ones provided by the toolchain.
This patch solves a rather common problem. The toolchain can usually generate code for many variants of target architecture and often even different endianness. The libgcc on the other hand is usually compiled for one particular configuration and the functions provided by it may or may not be suited for use in U-Boot. This can manifest in two ways, either the U-Boot fails to compile altogether and linker will complain or, in the much worse case, the resulting U-Boot will build, but will misbehave in very subtle and hard to debug ways.
Signed-off-by: Marek Vasut marex@denx.de Cc: Albert Aribaud albert.u.boot@aribaud.net Cc: Masahiro Yamada yamada.masahiro@socionext.com Cc: Simon Glass sjg@chromium.org Cc: Tom Rini trini@konsulko.com Reviewed-by: Tom Rini trini@konsulko.com
Applied to u-boot/master, thanks!
And since this change was contentious when previously proposed, I'm going to explain why I'm taking this now. There are a number of correctly configured toolchains out there today that fail to build U-Boot on some platforms. This is because we're giving the compiler conflicting requests (build soft-float! use whatever libgcc you have!). The era of multilib toolchains being prevalent (at least for 32bit ARM) is long over. The right thing to have done, always, would be to provide the required functions ourselves so that we are in control. So, thanks again Marek for following up on the series as I had asked you to, this fixes build failures for me on about a dozen platforms.
Thank you Marek!
- Simon
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