Added 32-bit RISC-V support. I have managed to get 32-bit RISC-V No-MMU Linux running based on mainstream buildroot. It's nice to have uclibc support this 32-bit No-MMU target.

There's no substantial code change except definations and config options.

Signed-off-by: Yimin Gu ustcymgu@gmail.com --- Rules.mak | 2 ++ extra/Configs/Config.in | 9 +++++++++ extra/Configs/Config.riscv32 | 14 ++++++++++++++ libc/sysdeps/linux/riscv32 | 1 + libc/sysdeps/linux/riscv64/bits/wordsize.h | 3 ++- libc/sysdeps/linux/riscv64/sys/asm.h | 6 +++++- 6 files changed, 33 insertions(+), 2 deletions(-) create mode 100644 extra/Configs/Config.riscv32 create mode 120000 libc/sysdeps/linux/riscv32

diff --git a/Rules.mak b/Rules.mak index 3fb64c728..71a14fc38 100644 --- a/Rules.mak +++ b/Rules.mak @@ -305,6 +305,7 @@ ifneq ($(TARGET_ARCH),c6x) ifneq ($(TARGET_ARCH),h8300) ifneq ($(TARGET_ARCH),arc) ifneq ($(TARGET_ARCH),aarch64) +ifneq ($(TARGET_ARCH),riscv32) CPU_CFLAGS-y += -msoft-float endif endif @@ -316,6 +317,7 @@ endif endif endif endif +endif

ifeq ($(TARGET_ARCH),aarch64) CPU_CFLAGS-y += -ftls-model=initial-exec diff --git a/extra/Configs/Config.in b/extra/Configs/Config.in index a58ceb265..5e6af800d 100644 --- a/extra/Configs/Config.in +++ b/extra/Configs/Config.in @@ -39,6 +39,7 @@ choice default TARGET_or1k if DESIRED_TARGET_ARCH = "or1k" default TARGET_powerpc if DESIRED_TARGET_ARCH = "powerpc" default TARGET_riscv64 if DESIRED_TARGET_ARCH = "riscv64" + default TARGET_riscv32 if DESIRED_TARGET_ARCH = "riscv32" default TARGET_sh if DESIRED_TARGET_ARCH = "sh" default TARGET_sparc if DESIRED_TARGET_ARCH = "sparc" default TARGET_sparc64 if DESIRED_TARGET_ARCH = "sparc64" @@ -125,6 +126,9 @@ config TARGET_powerpc config TARGET_riscv64 bool "riscv64"

+config TARGET_riscv32 + bool "riscv32" + config TARGET_sh bool "superh"

@@ -240,6 +244,10 @@ if TARGET_riscv64 source "extra/Configs/Config.riscv64" endif

+if TARGET_riscv32 +source "extra/Configs/Config.riscv32" +endif + if TARGET_sh source "extra/Configs/Config.sh" endif @@ -538,6 +546,7 @@ config UCLIBC_HAS_LINUXTHREADS select UCLIBC_HAS_REALTIME depends on !TARGET_aarch64 && \ !TARGET_riscv64 && \ + !TARGET_riscv32 && \ !TARGET_metag help If you want to compile uClibc with Linuxthreads support, then answer Y. diff --git a/extra/Configs/Config.riscv32 b/extra/Configs/Config.riscv32 new file mode 100644 index 000000000..304d30f70 --- /dev/null +++ b/extra/Configs/Config.riscv32 @@ -0,0 +1,14 @@ +# +# For a description of the syntax of this configuration file, +# see extra/config/Kconfig-language.txt +# + +config TARGET_ARCH + string + default "riscv32" + +config FORCE_OPTIONS_FOR_ARCH + bool + default y + select ARCH_LITTLE_ENDIAN + select ARCH_HAS_MMU diff --git a/libc/sysdeps/linux/riscv32 b/libc/sysdeps/linux/riscv32 new file mode 120000 index 000000000..11677ef05 --- /dev/null +++ b/libc/sysdeps/linux/riscv32 @@ -0,0 +1 @@ +riscv64 \ No newline at end of file diff --git a/libc/sysdeps/linux/riscv64/bits/wordsize.h b/libc/sysdeps/linux/riscv64/bits/wordsize.h index 67a16ba62..1fc649aad 100644 --- a/libc/sysdeps/linux/riscv64/bits/wordsize.h +++ b/libc/sysdeps/linux/riscv64/bits/wordsize.h @@ -25,5 +25,6 @@ #if __riscv_xlen == 64 # define __WORDSIZE_TIME64_COMPAT32 1 #else -# error "rv32i-based targets are not supported" +# define __WORDSIZE_TIME64_COMPAT32 1 +// # warning "rv32i-based targets are experimental" #endif diff --git a/libc/sysdeps/linux/riscv64/sys/asm.h b/libc/sysdeps/linux/riscv64/sys/asm.h index ddb84b683..3c94c9a70 100644 --- a/libc/sysdeps/linux/riscv64/sys/asm.h +++ b/libc/sysdeps/linux/riscv64/sys/asm.h @@ -26,7 +26,11 @@ # define REG_S sd # define REG_L ld #elif __riscv_xlen == 32 -# error "rv32i-based targets are not supported" +# define PTRLOG 2 +# define SZREG 4 +# define REG_S sw +# define REG_L lw +// # warning "rv32i-based targets are experimental" #else # error __riscv_xlen must equal 32 or 64 #endif