From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Petazzoni Date: Wed, 30 Dec 2020 23:35:59 +0100 Subject: [Buildroot] [PATCH] Revert "package/gdb: prevent gdbserver being selected for RISC-V builds" In-Reply-To: <20201204014549.2669932-1-vgupta@synopsys.com> References: <20201204014549.2669932-1-vgupta@synopsys.com> Message-ID: <20201230233559.5ea5c26b@windsurf> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: buildroot@busybox.net Hello, On Thu, 3 Dec 2020 17:45:49 -0800 Vineet Gupta wrote: > This reverts commit 44a9babcc67cd011e957ba9fd1cf741891957c12. > > As of Buildroot 2020.11 (glibc build of qemu_riscv64_virt_defconfig), > cross-gdb for RISCV buildis fine and can also attach to a qemu > instance, so remove the gate on not building it. > > Signed-off-by: Vineet Gupta I am sorry, but I don't see how this can work. RISC-V support in gdbserver was only added in upstream gdb in commit bf84f7066626c78884436e1c39fb60f04c665f21, which first appeared in gdb 10.1. And indeed, when I build: BR2_riscv=y BR2_TOOLCHAIN_EXTERNAL=y BR2_TOOLCHAIN_EXTERNAL_DOWNLOAD=y BR2_TOOLCHAIN_EXTERNAL_URL="http://autobuild.buildroot.net/toolchains/tarballs/br-riscv64-musl-2020.02.tar.bz2" BR2_TOOLCHAIN_EXTERNAL_GCC_9=y BR2_TOOLCHAIN_EXTERNAL_HEADERS_4_19=y BR2_TOOLCHAIN_EXTERNAL_CUSTOM_MUSL=y BR2_TOOLCHAIN_EXTERNAL_CXX=y BR2_PACKAGE_HOST_GDB=y BR2_INIT_NONE=y BR2_SYSTEM_BIN_SH_NONE=y # BR2_PACKAGE_BUSYBOX is not set BR2_PACKAGE_GDB=y # BR2_TARGET_ROOTFS_TAR is not set It fails to build gdbserver, with: Error: target not supported by gdbserver. However, if I build: BR2_riscv=y BR2_TOOLCHAIN_EXTERNAL=y BR2_TOOLCHAIN_EXTERNAL_DOWNLOAD=y BR2_TOOLCHAIN_EXTERNAL_URL="http://autobuild.buildroot.net/toolchains/tarballs/br-riscv64-musl-2020.02.tar.bz2" BR2_TOOLCHAIN_EXTERNAL_GCC_9=y BR2_TOOLCHAIN_EXTERNAL_HEADERS_4_19=y BR2_TOOLCHAIN_EXTERNAL_CUSTOM_MUSL=y BR2_TOOLCHAIN_EXTERNAL_CXX=y BR2_PACKAGE_HOST_GDB=y BR2_GDB_VERSION_10=y BR2_INIT_NONE=y BR2_SYSTEM_BIN_SH_NONE=y # BR2_PACKAGE_BUSYBOX is not set BR2_PACKAGE_GDB=y # BR2_TARGET_ROOTFS_TAR is not set which uses gdb 10.x, then indeed, the gdbserver configure script recognizes RISC-V as a supported CPU architecture, but it fails to build with: ../../gdbserver/linux-riscv-low.cc: In function ?void riscv_fill_fpregset(regcache*, void*)?: ../../gdbserver/linux-riscv-low.cc:140:19: error: ?ELF_NFPREG? was not declared in this scope; did you mean ?ELF_NGREG?? 140 | for (i = 0; i < ELF_NFPREG - 1; i++, regbuf += flen) | ^~~~~~~~~~ | ELF_NGREG ../../gdbserver/linux-riscv-low.cc: In function ?void riscv_store_fpregset(regcache*, const void*)?: ../../gdbserver/linux-riscv-low.cc:156:19: error: ?ELF_NFPREG? was not declared in this scope; did you mean ?ELF_NGREG?? 156 | for (i = 0; i < ELF_NFPREG - 1; i++, regbuf += flen) | ^~~~~~~~~~ | ELF_NGREG Note: this is with a musl toolchain, it is possible that it builds fine with a glibc toolchain. But regardless of that, RISC-V support in gdbserver only appeared in gdb 10.x, so I don't see how your patch could have worked, as we only introduced gdb 10.x support in Buildroot yesterday. Could you clarify ? Best regards, Thomas -- Thomas Petazzoni, CTO, Bootlin Embedded Linux and Kernel engineering https://bootlin.com