Hi Bin, On Fri, May 24, 2019 at 05:40:08PM +0800, Bin Meng wrote: > Hi Eric, > > On Fri, May 24, 2019 at 4:04 PM Eric Lin <dslin1...@gmail.com> wrote: > > > > Hi Bin > > > > Bin Meng <bmeng...@gmail.com> ??? 2019???5???22??? ?????? > > ??????5:25????????? > > > > > > Hi Eric, > > > > > > On Wed, May 22, 2019 at 4:23 PM <tesh...@andestech.com> wrote: > > > > > > > > Hi Bin, > > > > > > > > > -----Original Message----- > > > > > From: Bin Meng [mailto:bmeng...@gmail.com] > > > > > Sent: Tuesday, May 21, 2019 3:56 PM > > > > > To: Eric Te-Sheng Lin(?????????) > > > > > Cc: U-Boot Mailing List; Lukas Auer; Anup Patel; Rick Jian-Zhi > > > > > Chen(?????????); > > > > > Greentime Ying-Han Hu(?????????); dslin1...@gmail.com > > > > > Subject: Re: [PATCH] riscv: add Kconfig entries for the F and D ISA > > > > > extensions > > > > > support > > > > > > > > > > Hi Eric, > > > > > > > > > > On Tue, May 21, 2019 at 3:18 PM Eric Lin <tesh...@andestech.com> > > > > > wrote: > > > > > > > > > > > > This patch add Kconfig entries for the F (Single-Precision) > > > > > > > > > > adds > > > > > > > > > > > > > OK I'll correct it as adds > > > > > > > > > > and D (Double-Precision) floating point instruction-set extensions. > > > > > > > > > > > > > > > > Could you please provide reason that why U-Boot has to be compiled > > > > > using F/D > > > > > extension? > > > > > > > > > > > > > Cause on AE350 platform, we have two different kinds of toolchain v5d > > > > (support I/M/A/C/F/D ISA) and > > > > v5 (support I/M/A/C ISA). If we use the v5d toolchain to build U-Boot > > > > it will build fail, so we would like to add F/D extension on U-Boot. > > > > > > I don't understand. What difference do these two toochains have? Isn't > > > the v5d toolchain's default -march string be pre-configured to imafd? > > > But even if the toolchain is pre-configured to generate fd > > > instruction, I think it can be override by the compiler flags. Can you > > > please share the details of the toolchain you used? I suspect you have > > > to fix your toolchain, not U-Boot. > > > > > > > It's seems the ABI issue. Because our toolchain don't support > > multilib, the v5d toolchain libraries ABI is ilp64d. > > If I use the v5d toolchain to build U-Boot with -mabi=lp64, it will > > get link error as below: > > Then please fix your compiler. Passing -mabi=lp64 to compiler is > definitely correct.
One of our customer ever used floating point in their project. They want to calculate something with floating point instructions in u-Boot before entering kernel. IMHO, we may consider this case for user to use -mabi=ilp64d. This CONFIG will be useful for them to compile their codes and linking together with u-Boot. Thanks :) _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot
