diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index e51aee06..0554a69b 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -50,6 +50,7 @@ on:
         - mips-zephyr-elf
         - nios2-zephyr-elf
         - riscv64-zephyr-elf
+        - rx-zephyr-elf
         - sparc-zephyr-elf
         - x86_64-zephyr-elf
         - xtensa-amd_acp_6_0_adsp_zephyr-elf
@@ -170,6 +171,7 @@ jobs:
             mips-zephyr-elf)                      build_target_mips_zephyr_elf="y";;
             nios2-zephyr-elf)                     build_target_nios2_zephyr_elf="y";;
             riscv64-zephyr-elf)                   build_target_riscv64_zephyr_elf="y";;
+            rx-zephyr-elf)                        build_target_rx_zephyr_elf="y";;
             sparc-zephyr-elf)                     build_target_sparc_zephyr_elf="y";;
             x86_64-zephyr-elf)                    build_target_x86_64_zephyr_elf="y";;
             xtensa-amd_acp_6_0_adsp_zephyr-elf)   build_target_xtensa_amd_acp_6_0_adsp_zephyr_elf="y";;
@@ -218,6 +220,7 @@ jobs:
           build_target_mips_zephyr_elf="y"
           build_target_nios2_zephyr_elf="y"
           build_target_riscv64_zephyr_elf="y"
+          build_target_rx_zephyr_elf="y"
           build_target_sparc_zephyr_elf="y"
           build_target_x86_64_zephyr_elf="y"
           build_target_xtensa_amd_acp_6_0_adsp_zephyr_elf="y"
@@ -306,6 +309,7 @@ jobs:
         [ "${build_target_mips_zephyr_elf}" == "y" ]                      && MATRIX_TARGETS+='"mips-zephyr-elf",'
         [ "${build_target_nios2_zephyr_elf}" == "y" ]                     && MATRIX_TARGETS+='"nios2-zephyr-elf",'
         [ "${build_target_riscv64_zephyr_elf}" == "y" ]                   && MATRIX_TARGETS+='"riscv64-zephyr-elf",'
+        [ "${build_target_rx_zephyr_elf}" == "y" ]                        && MATRIX_TARGETS+='"rx-zephyr-elf",'
         [ "${build_target_sparc_zephyr_elf}" == "y" ]                     && MATRIX_TARGETS+='"sparc-zephyr-elf",'
         [ "${build_target_x86_64_zephyr_elf}" == "y" ]                    && MATRIX_TARGETS+='"x86_64-zephyr-elf",'
         [ "${build_target_xtensa_amd_acp_6_0_adsp_zephyr_elf}" == "y" ]   && MATRIX_TARGETS+='"xtensa-amd_acp_6_0_adsp_zephyr-elf",'
@@ -1556,6 +1560,9 @@ jobs:
               PLATFORM_ARGS+="-p qemu_riscv32e "
               PLATFORM_ARGS+="-p qemu_riscv64 "
               ;;
+            rx-zephyr-elf)
+              PLATFORM_ARGS+="-p qemu_rx "
+              ;;
             sparc-zephyr-elf)
               PLATFORM_ARGS+="-p qemu_leon3 "
               ;;
diff --git a/.gitmodules b/.gitmodules
index 664ce429..9cb64bc4 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -1,6 +1,6 @@
 [submodule "crosstool-ng"]
 	path = crosstool-ng
-	url = https://github.com/zephyrproject-rtos/crosstool-ng.git
+	url = https://github.com/renesas/crosstool-ng.git
 [submodule "binutils"]
 	path = binutils
 	url = https://github.com/zephyrproject-rtos/binutils-gdb.git
@@ -9,13 +9,13 @@
 	url = https://github.com/zephyrproject-rtos/newlib-cygwin.git
 [submodule "gcc"]
 	path = gcc
-	url = https://github.com/zephyrproject-rtos/gcc.git
+	url = https://github.com/renesas/gcc.git
 [submodule "gdb"]
 	path = gdb
 	url = https://github.com/zephyrproject-rtos/binutils-gdb.git
 [submodule "picolibc"]
 	path = picolibc
-	url = https://github.com/zephyrproject-rtos/picolibc.git
+	url = https://github.com/renesas/picolibc.git
 [submodule "crosskit-x86_64-apple-darwin"]
 	path = crosskit/crosskit-x86_64-apple-darwin
 	url = https://github.com/zephyrproject-rtos/crosskit-x86_64-apple-darwin.git
diff --git a/README.md b/README.md
index c731b84b..d4f6cc4b 100644
--- a/README.md
+++ b/README.md
@@ -12,6 +12,7 @@ The toolchains for the following target architectures are supported:
 - MIPS (32-bit and 64-bit)
 - Nios II
 - RISC-V (32-bit and 64-bit; RV32I, RV32E, RV64I)
+- RX
 - SPARC (32-bit and 64-bit; SPARC V8, SPARC V9)
 - x86 (32-bit and 64-bit)
 - Xtensa (sample_controller and other vendor-specific variants)
diff --git a/cmake/zephyr/target.cmake b/cmake/zephyr/target.cmake
index 2d485778..8fc12ebf 100644
--- a/cmake/zephyr/target.cmake
+++ b/cmake/zephyr/target.cmake
@@ -10,6 +10,7 @@ set(CROSS_COMPILE_TARGET_arm64   aarch64-zephyr-elf)
 set(CROSS_COMPILE_TARGET_nios2     nios2-zephyr-elf)
 set(CROSS_COMPILE_TARGET_riscv   riscv64-zephyr-elf)
 set(CROSS_COMPILE_TARGET_mips       mips-zephyr-elf)
+set(CROSS_COMPILE_TARGET_rx           rx-zephyr-elf)
 set(CROSS_COMPILE_TARGET_microblaze microblazeel-zephyr-elf)
 set(CROSS_COMPILE_TARGET_xtensa   xtensa-${SOC_TOOLCHAIN_NAME}_zephyr-elf)
 
diff --git a/configs/rx-zephyr-elf.config b/configs/rx-zephyr-elf.config
new file mode 100644
index 00000000..157cb336
--- /dev/null
+++ b/configs/rx-zephyr-elf.config
@@ -0,0 +1,6 @@
+CT_CONFIG_VERSION="3"
+CT_EXPERIMENTAL=y
+CT_ARCH_RX=y
+CT_TARGET_CFLAGS="-ftls-model=local-exec"
+CT_TARGET_VENDOR="zephyr"
+CT_MULTILIB=y
diff --git a/crosstool-ng b/crosstool-ng
index 53b5327d..2c07faf2 160000
--- a/crosstool-ng
+++ b/crosstool-ng
@@ -1 +1 @@
-Subproject commit 53b5327d821a6b6949fa455f14a9631146af897c
+Subproject commit 2c07faf2989dce986c10740c0cd8a22bb62d8b88
diff --git a/gcc b/gcc
index 428d8d7b..120864a3 160000
--- a/gcc
+++ b/gcc
@@ -1 +1 @@
-Subproject commit 428d8d7b0542338244ca41ac06a5f3fa4f29bb6d
+Subproject commit 120864a3cd6b248f40666a2b1f1afb66ca77498b
diff --git a/picolibc b/picolibc
index d492d5fa..924add94 160000
--- a/picolibc
+++ b/picolibc
@@ -1 +1 @@
-Subproject commit d492d5fa7c96918e37653f303028346bb0dd51a2
+Subproject commit 924add9419cd56d7c3aa7937e7bbb77402d3d531