LINK is setted to riscv64-unknown-elf-gcc， but env.Program execute use ld

[zhajio1988]

LINK is setted to riscv64-unknown-elf-gcc， but env.Program execute use ld.
I use env.Dump(）get below outputs:
'LINK': 'riscv64-unknown-elf-gcc', 'LINKCOM': '$LINK -o $TARGET $LINKFLAGS $__RPATH $SOURCES $_LIBDIRFLAGS ' '$_LIBFLAGS', 'LINKFLAGS': ' ' '-march=rv64imafdcv_zicbom_zicbop_zicboz_zicond1p0_zihintntl0p2_zihintpause_zawrs_zfa0p1_zfbfmin0p8_zfh_zca_zcb_zcd_zba_zbb_zbc_zbs_zvfbfmin0p8_zvfbfwma0p8_svinval_svpbmt_xtheadc_xtheadvdot ' '-mabi=lp64d -mtune=c920 -nostartfiles -lc -lgcc -lm -T ' '/ssd_fes/jiongz/desktop/github/diff_ip_vv/pc801_c920_ip_vv/smart_run/tests/lib/init/linker.lcf ' '-L ' '/ssd_fes/jiongz/desktop/github/diff_ip_vv/pc801_c920_ip_vv/smart_run/tests/lib/init',
Could anyone help me about this issue?

[mwichmann]

Curious why your target arch spec looks so odd? I'd expect just rv64i? Is this including all the build options or something?

-march=rv64imafdcv_zicbom_zicbop_zicboz_zicond1p0_zihintntl0p2_zihintpause_zawrs_zfa0p1_zfbfmin0p8_zfh_zca_zcb_zcd_zba_zbb_zbc_zbs_zvfbfmin0p8_zvfbfwma0p8_svinval_svpbmt_xtheadc_xtheadvdot

While most builds using a gcc toolcchain use the special variable $SMARTLINK it should certainly be possible to set $LINK to something more specific - we do it in many tests in the regression test suite. The smart link concept is to basically use the same program as is being used for compilation (so the same as $CC if it's C code, $CXX if it's C++, etc). Have you tried that?

It's not SCons executing ld: it issues the expanded version of the $LINKCOM command. If the program you invoke there goes on and calls other programs, that's it's business. Sounds like possibly the gcc build (presumably this is a cross-build toolchain?) isn't configured in a way that it's picking up the linker binary you expect. Based on the naming from above, would be expecting it to look for riscv64-unknown-elf-ld.

[bdbaddog]

@zhajio1988 base questions first

1. Which version of SCons?
2. Which version of Python?
3. Which operating system are you on?
4. Can you provide a small reproducer?

[bdbaddog]

Can you run scons --debug=presub and paste the debug information just prior to your build failure (don't build in parallel for this)?

[zhajio1988]

Curious why your target arch spec looks so odd? I'd expect just rv64i? Is this including all the build options or something?

-march=rv64imafdcv_zicbom_zicbop_zicboz_zicond1p0_zihintntl0p2_zihintpause_zawrs_zfa0p1_zfbfmin0p8_zfh_zca_zcb_zcd_zba_zbb_zbc_zbs_zvfbfmin0p8_zvfbfwma0p8_svinval_svpbmt_xtheadc_xtheadvdot

While most builds using a gcc toolcchain use the special variable $SMARTLINK it should certainly be possible to set $LINK to something more specific - we do it in many tests in the regression test suite. The smart link concept is to basically use the same program as is being used for compilation (so the same as $CC if it's C code, $CXX if it's C++, etc). Have you tried that?

It's not SCons executing ld: it issues the expanded version of the $LINKCOM command. If the program you invoke there goes on and calls other programs, that's it's business. Sounds like possibly the gcc build (presumably this is a cross-build toolchain?) isn't configured in a way that it's picking up the linker binary you expect. Based on the naming from above, would be expecting it to look for riscv64-unknown-elf-ld.

@mwichmann The -march option is copied from T-head‘s makefile. ld command finally point to ”/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/../lib/gcc/riscv64-unknown-elf/10.4.0/../../../../riscv64-unknown-elf/bin/ld”

[zhajio1988]

Hi @bdbaddog
Thanks for your replay.

1. Which version of SCons?
   SCons: v4.8.0.7c688f694c644b61342670ce92977bf4a396c0d4, Sun, 07 Jul 2024 16:52:07 -0700, by bdbaddog on M1Dog2021
2. Which version of Python?
   Python 3.11.4 (main, Jul 5 2023, 13:45:01) [GCC 11.2.0] on linux
3. Which operating system are you on?
   Linux lushan 3.10.0-957.el7.x86_64 ParseConfig doesn't understand -Wl flags. #1 SMP Thu Nov 8 23:39:32 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux
4. Can you provide a small reproducer?
   I will try to do this.

[zhajio1988]

Can you run scons --debug=presub and paste the debug information just prior to your build failure (don't build in parallel for this)?

Building build/arch/t-head/barrier.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
CC build/arch/t-head/barrier.o
Building build/arch/t-head/cache.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
CC build/arch/t-head/cache.o
Building build/lib/clib/fputc.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
CC build/lib/clib/fputc.o
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/riscv64-unknown-elf/include/stdio.h: In function 'fputc':
tests/lib/clib/fputc.c:19:1: warning: control reaches end of non-void function [-Wreturn-type]
   19 | }
      | ^
Building build/lib/clib/intc.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
CC build/lib/clib/intc.o
tests/lib/clib/intc.c: In function 'ck_intc_init':
tests/lib/clib/intc.c:9:34: warning: initialization of 'int *' from 'int' makes pointer from integer without a cast [-Wint-conversion]
    9 | #define APB_BASE                 0x10000000
      |                                  ^~~~~~~~~~
tests/lib/clib/intc.c:15:17: note: in expansion of macro 'APB_BASE'
   15 |     int *picr = APB_BASE;
      |                 ^~~~~~~~
tests/lib/clib/intc.c:10:34: warning: initialization of 'int *' from 'int' makes pointer from integer without a cast [-Wint-conversion]
   10 | #define INTC_BASE                0x10010000
      |                                  ^~~~~~~~~~
tests/lib/clib/intc.c:19:22: note: in expansion of macro 'INTC_BASE'
   19 |         int *piser = INTC_BASE + 0x10;
      |                      ^~~~~~~~~
Building build/lib/clib/uart.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
CC build/lib/clib/uart.o
tests/lib/clib/uart.c: In function 'ck_uart_status':
tests/lib/clib/uart.c:203:18: warning: 'uart_lsr' is used uninitialized in this function [-Wuninitialized]
  203 |     if (uart_lsr & CK_LSR_TEMT)
      |                  ^
Building build/lib/clib/vtimer.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
CC build/lib/clib/vtimer.o
tests/lib/clib/vtimer.c: In function 'sim_end':
tests/lib/clib/vtimer.c:21:12: warning: assignment to 'int *' from 'unsigned int' makes pointer from integer without a cast [-Wint-conversion]
   21 |   END_ADDR = 0xA001FF48;
      |            ^
tests/lib/clib/vtimer.c:24:13: warning: unsigned conversion from 'long int' to 'unsigned int' changes value from '18324075042' to '1144205858' [-Woverflow]
   24 |   END_DATA= 0x444333222;
      |             ^~~~~~~~~~~
Building build/lib/init/core_cp0.o with action:
  $CC $ASPPFLAGS $CPPFLAGS $_CPPDEFFLAGS $_CPPINCFLAGS -c -o $TARGET $SOURCES
AS build/lib/init/core_cp0.o
Building build/lib/init/core_ifu.o with action:
  $CC $ASPPFLAGS $CPPFLAGS $_CPPDEFFLAGS $_CPPINCFLAGS -c -o $TARGET $SOURCES
AS build/lib/init/core_ifu.o
Building build/lib/init/core_l2c.o with action:
  $CC $ASPPFLAGS $CPPFLAGS $_CPPDEFFLAGS $_CPPINCFLAGS -c -o $TARGET $SOURCES
AS build/lib/init/core_l2c.o
Building build/lib/init/core_lsu.o with action:
  $CC $ASPPFLAGS $CPPFLAGS $_CPPDEFFLAGS $_CPPINCFLAGS -c -o $TARGET $SOURCES
AS build/lib/init/core_lsu.o
Building build/lib/init/core_mmu.o with action:
  $CC $ASPPFLAGS $CPPFLAGS $_CPPDEFFLAGS $_CPPINCFLAGS -c -o $TARGET $SOURCES
AS build/lib/init/core_mmu.o
Building build/lib/init/core_plic.o with action:
  $CC $ASPPFLAGS $CPPFLAGS $_CPPDEFFLAGS $_CPPINCFLAGS -c -o $TARGET $SOURCES
AS build/lib/init/core_plic.o
Building build/lib/init/core_t_extension.o with action:
  $CC $ASPPFLAGS $CPPFLAGS $_CPPDEFFLAGS $_CPPINCFLAGS -c -o $TARGET $SOURCES
AS build/lib/init/core_t_extension.o
Building build/lib/init/core_vec.o with action:
  $CC $ASPPFLAGS $CPPFLAGS $_CPPDEFFLAGS $_CPPINCFLAGS -c -o $TARGET $SOURCES
AS build/lib/init/core_vec.o
Building build/lib/init/crt0.o with action:
  $CC $ASPPFLAGS $CPPFLAGS $_CPPDEFFLAGS $_CPPINCFLAGS -c -o $TARGET $SOURCES
AS build/lib/init/crt0.o
Building build/lib/init/stress_inst.o with action:
  $CC $ASPPFLAGS $CPPFLAGS $_CPPDEFFLAGS $_CPPINCFLAGS -c -o $TARGET $SOURCES
AS build/lib/init/stress_inst.o
Building build/lib/newlib_wrap/__dtostr.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
CC build/lib/newlib_wrap/__dtostr.o
Building build/lib/newlib_wrap/__isinf.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
CC build/lib/newlib_wrap/__isinf.o
Building build/lib/newlib_wrap/__isnan.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
CC build/lib/newlib_wrap/__isnan.o
Building build/lib/newlib_wrap/__lltostr.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
CC build/lib/newlib_wrap/__lltostr.o
Building build/lib/newlib_wrap/__ltostr.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
CC build/lib/newlib_wrap/__ltostr.o
Building build/lib/newlib_wrap/__v_printf.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
CC build/lib/newlib_wrap/__v_printf.o
Building build/lib/newlib_wrap/fprintf.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
CC build/lib/newlib_wrap/fprintf.o
Building build/lib/newlib_wrap/getc.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
CC build/lib/newlib_wrap/getc.o
Building build/lib/newlib_wrap/getchar.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
CC build/lib/newlib_wrap/getchar.o
Building build/lib/newlib_wrap/printf.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
CC build/lib/newlib_wrap/printf.o
Building build/lib/newlib_wrap/putc.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
CC build/lib/newlib_wrap/putc.o
Building build/lib/newlib_wrap/putchar.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
CC build/lib/newlib_wrap/putchar.o
Building build/lib/newlib_wrap/puts.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
CC build/lib/newlib_wrap/puts.o
Building build/lib/newlib_wrap/snprintf.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
CC build/lib/newlib_wrap/snprintf.o
Building build/lib/newlib_wrap/sprintf.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
CC build/lib/newlib_wrap/sprintf.o
Building build/lib/newlib_wrap/vfprintf.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
CC build/lib/newlib_wrap/vfprintf.o
Building build/lib/newlib_wrap/vprintf.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
CC build/lib/newlib_wrap/vprintf.o
Building build/lib/newlib_wrap/vsnprintf.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
CC build/lib/newlib_wrap/vsnprintf.o
Building build/lib/newlib_wrap/vsprintf.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
CC build/lib/newlib_wrap/vsprintf.o
Building build/tests/hello_world/hello_world.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
CC build/tests/hello_world/hello_world.o
tests/cases/hello_world/hello_world.c: In function 'main':
tests/cases/hello_world/hello_world.c:39:1: warning: this 'else' clause does not guard... [-Wmisleading-indentation]
   39 | else
      | ^~~~
tests/cases/hello_world/hello_world.c:41:3: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'else'
   41 |   printf("after ASM c is changed to %d!\n",c);
      |   ^~~~~~
Building hello_world.elf with action:
  $LINK -o $TARGET $LINKFLAGS $__RPATH $SOURCES $_LIBDIRFLAGS $_LIBFLAGS
LINK hello_world.elf
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/../lib/gcc/riscv64-unknown-elf/10.4.0/../../../../riscv64-unknown-elf/bin/ld: /opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/../lib/gcc/riscv64-unknown-elf/10.4.0/../../../../riscv64-unknown-elf/lib/rv64imafdcv_zfh_xtheadc/lp64d/crt0.o: in function `_start':
(.text+0x0): undefined reference to `__global_pointer$'
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/../lib/gcc/riscv64-unknown-elf/10.4.0/../../../../riscv64-unknown-elf/bin/ld: (.text+0x8): undefined reference to `_edata'
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/../lib/gcc/riscv64-unknown-elf/10.4.0/../../../../riscv64-unknown-elf/bin/ld: (.text+0x10): undefined reference to `_end'
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/../lib/gcc/riscv64-unknown-elf/10.4.0/../../../../riscv64-unknown-elf/bin/ld: (.text+0x32): undefined reference to `__libc_init_array'
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/../lib/gcc/riscv64-unknown-elf/10.4.0/../../../../riscv64-unknown-elf/bin/ld: (.text+0x44): undefined reference to `exit'
collect2: error: ld returned 1 exit status
scons: *** [hello_world.elf] Error 1

[zhajio1988]

@bdbaddog
scons_demo.tar.gz
Attached is a small example, please help to look at it thanks.
Below is the log:

Building lib/clib/fputc.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -o lib/clib/fputc.o -c -O1 -g -Wall -Ilib/clib -Ilib/newlib_wrap -Ilib/init lib/clib/fputc.c
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/riscv64-unknown-elf/include/stdio.h: In function 'fputc':
lib/clib/fputc.c:19:1: warning: control reaches end of non-void function [-Wreturn-type]
   19 | }
      | ^
Building lib/clib/intc.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -o lib/clib/intc.o -c -O1 -g -Wall -Ilib/clib -Ilib/newlib_wrap -Ilib/init lib/clib/intc.c
lib/clib/intc.c: In function 'ck_intc_init':
lib/clib/intc.c:9:34: warning: initialization of 'int *' from 'int' makes pointer from integer without a cast [-Wint-conversion]
    9 | #define APB_BASE                 0x10000000
      |                                  ^~~~~~~~~~
lib/clib/intc.c:15:17: note: in expansion of macro 'APB_BASE'
   15 |     int *picr = APB_BASE;
      |                 ^~~~~~~~
lib/clib/intc.c:10:34: warning: initialization of 'int *' from 'int' makes pointer from integer without a cast [-Wint-conversion]
   10 | #define INTC_BASE                0x10010000
      |                                  ^~~~~~~~~~
lib/clib/intc.c:19:22: note: in expansion of macro 'INTC_BASE'
   19 |         int *piser = INTC_BASE + 0x10;
      |                      ^~~~~~~~~
Building lib/clib/uart.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -o lib/clib/uart.o -c -O1 -g -Wall -Ilib/clib -Ilib/newlib_wrap -Ilib/init lib/clib/uart.c
lib/clib/uart.c: In function 'ck_uart_status':
lib/clib/uart.c:203:18: warning: 'uart_lsr' is used uninitialized in this function [-Wuninitialized]
  203 |     if (uart_lsr & CK_LSR_TEMT)
      |                  ^
Building lib/clib/vtimer.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -o lib/clib/vtimer.o -c -O1 -g -Wall -Ilib/clib -Ilib/newlib_wrap -Ilib/init lib/clib/vtimer.c
lib/clib/vtimer.c: In function 'sim_end':
lib/clib/vtimer.c:21:12: warning: assignment to 'int *' from 'unsigned int' makes pointer from integer without a cast [-Wint-conversion]
   21 |   END_ADDR = 0xA001FF48;
      |            ^
lib/clib/vtimer.c:24:13: warning: unsigned conversion from 'long int' to 'unsigned int' changes value from '18324075042' to '1144205858' [-Woverflow]
   24 |   END_DATA= 0x444333222;
      |             ^~~~~~~~~~~
Building lib/newlib_wrap/__dtostr.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -o lib/newlib_wrap/__dtostr.o -c -O1 -g -Wall -Ilib/clib -Ilib/newlib_wrap -Ilib/init lib/newlib_wrap/__dtostr.c
Building lib/newlib_wrap/__isinf.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -o lib/newlib_wrap/__isinf.o -c -O1 -g -Wall -Ilib/clib -Ilib/newlib_wrap -Ilib/init lib/newlib_wrap/__isinf.c
Building lib/newlib_wrap/__isnan.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -o lib/newlib_wrap/__isnan.o -c -O1 -g -Wall -Ilib/clib -Ilib/newlib_wrap -Ilib/init lib/newlib_wrap/__isnan.c
Building lib/newlib_wrap/__lltostr.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -o lib/newlib_wrap/__lltostr.o -c -O1 -g -Wall -Ilib/clib -Ilib/newlib_wrap -Ilib/init lib/newlib_wrap/__lltostr.c
Building lib/newlib_wrap/__ltostr.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -o lib/newlib_wrap/__ltostr.o -c -O1 -g -Wall -Ilib/clib -Ilib/newlib_wrap -Ilib/init lib/newlib_wrap/__ltostr.c
Building lib/newlib_wrap/__v_printf.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -o lib/newlib_wrap/__v_printf.o -c -O1 -g -Wall -Ilib/clib -Ilib/newlib_wrap -Ilib/init lib/newlib_wrap/__v_printf.c
Building lib/newlib_wrap/fprintf.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -o lib/newlib_wrap/fprintf.o -c -O1 -g -Wall -Ilib/clib -Ilib/newlib_wrap -Ilib/init lib/newlib_wrap/fprintf.c
Building lib/newlib_wrap/getc.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -o lib/newlib_wrap/getc.o -c -O1 -g -Wall -Ilib/clib -Ilib/newlib_wrap -Ilib/init lib/newlib_wrap/getc.c
Building lib/newlib_wrap/getchar.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -o lib/newlib_wrap/getchar.o -c -O1 -g -Wall -Ilib/clib -Ilib/newlib_wrap -Ilib/init lib/newlib_wrap/getchar.c
Building lib/newlib_wrap/printf.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -o lib/newlib_wrap/printf.o -c -O1 -g -Wall -Ilib/clib -Ilib/newlib_wrap -Ilib/init lib/newlib_wrap/printf.c
Building lib/newlib_wrap/putc.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -o lib/newlib_wrap/putc.o -c -O1 -g -Wall -Ilib/clib -Ilib/newlib_wrap -Ilib/init lib/newlib_wrap/putc.c
Building lib/newlib_wrap/putchar.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -o lib/newlib_wrap/putchar.o -c -O1 -g -Wall -Ilib/clib -Ilib/newlib_wrap -Ilib/init lib/newlib_wrap/putchar.c
Building lib/newlib_wrap/puts.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -o lib/newlib_wrap/puts.o -c -O1 -g -Wall -Ilib/clib -Ilib/newlib_wrap -Ilib/init lib/newlib_wrap/puts.c
Building lib/newlib_wrap/snprintf.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -o lib/newlib_wrap/snprintf.o -c -O1 -g -Wall -Ilib/clib -Ilib/newlib_wrap -Ilib/init lib/newlib_wrap/snprintf.c
Building lib/newlib_wrap/sprintf.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -o lib/newlib_wrap/sprintf.o -c -O1 -g -Wall -Ilib/clib -Ilib/newlib_wrap -Ilib/init lib/newlib_wrap/sprintf.c
Building lib/newlib_wrap/vfprintf.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -o lib/newlib_wrap/vfprintf.o -c -O1 -g -Wall -Ilib/clib -Ilib/newlib_wrap -Ilib/init lib/newlib_wrap/vfprintf.c
Building lib/newlib_wrap/vprintf.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -o lib/newlib_wrap/vprintf.o -c -O1 -g -Wall -Ilib/clib -Ilib/newlib_wrap -Ilib/init lib/newlib_wrap/vprintf.c
Building lib/newlib_wrap/vsnprintf.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -o lib/newlib_wrap/vsnprintf.o -c -O1 -g -Wall -Ilib/clib -Ilib/newlib_wrap -Ilib/init lib/newlib_wrap/vsnprintf.c
Building lib/newlib_wrap/vsprintf.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -o lib/newlib_wrap/vsprintf.o -c -O1 -g -Wall -Ilib/clib -Ilib/newlib_wrap -Ilib/init lib/newlib_wrap/vsprintf.c
Building hello_world.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -o hello_world.o -c -O1 -g -Wall -Ilib/clib -Ilib/newlib_wrap -Ilib/init hello_world.c
hello_world.c: In function 'main':
hello_world.c:39:1: warning: this 'else' clause does not guard... [-Wmisleading-indentation]
   39 | else
      | ^~~~
hello_world.c:41:3: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'else'
   41 |   printf("after ASM c is changed to %d!\n",c);
      |   ^~~~~~
Building lib/init/core_cp0.o with action:
  $AS $ASFLAGS -o $TARGET $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -g -o lib/init/core_cp0.o lib/init/core_cp0.s
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/../lib/gcc/riscv64-unknown-elf/10.4.0/../../../../riscv64-unknown-elf/bin/ld: /opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/../lib/gcc/riscv64-unknown-elf/10.4.0/../../../../riscv64-unknown-elf/lib/rv64imafdc_zfh_xtheadc/lp64d/crt0.o: in function `.L0 ':
(.text+0x38): undefined reference to `main'
collect2: error: ld returned 1 exit status
scons: *** [lib/init/core_cp0.o] Error 1

[mwichmann]

At a first glance, the setting of AS seems dodgy - you normally don't want to use gcc as "the assembler". At least in the snip just above, you have:

Building lib/init/core_cp0.o with action:
  $AS $ASFLAGS -o $TARGET $SOURCES
LONGPREFIX/bin/riscv64-unknown-elf-gcc -g -o lib/init/core_cp0.o lib/init/core_cp0.s

and then an error from the linker, indicating it's trying to make a program out of it, rather than an object:

ZZZ/lp64d/crt0.o: in function `.L0 ':
(.text+0x38): undefined reference to `main'
collect2: error: ld returned 1 exit status

I'd expect the line from building this object file from assembly to look like:

LONGPREFIX/bin/riscv64-unknown-elf-as -g -o lib/init/core_cp0.o lib/init/core_cp0.s

Maybe if you try that change first, we can see if there are other issues.

EDITED: that is, in the SConstruct, make a change like:

-AS      = PREFIX + 'gcc'
+AS      = PREFIX + 'as'

[zhajio1988]

Thanks for your help. @mwichmann
After EDITED AS = PREFIX + 'as'
Report below logs:

> Building lib/init/core_cp0.o with action:
  $AS $ASFLAGS -o $TARGET $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-as -g -o lib/init/core_cp0.o lib/init/core_cp0.s
Building lib/init/core_ifu.o with action:
  $AS $ASFLAGS -o $TARGET $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-as -g -o lib/init/core_ifu.o lib/init/core_ifu.s
Building lib/init/core_l2c.o with action:
  $AS $ASFLAGS -o $TARGET $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-as -g -o lib/init/core_l2c.o lib/init/core_l2c.s
Building lib/init/core_lsu.o with action:
  $AS $ASFLAGS -o $TARGET $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-as -g -o lib/init/core_lsu.o lib/init/core_lsu.s
Building lib/init/core_mmu.o with action:
  $AS $ASFLAGS -o $TARGET $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-as -g -o lib/init/core_mmu.o lib/init/core_mmu.s
Building lib/init/core_plic.o with action:
  $AS $ASFLAGS -o $TARGET $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-as -g -o lib/init/core_plic.o lib/init/core_plic.s
Building lib/init/core_t_extension.o with action:
  $AS $ASFLAGS -o $TARGET $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-as -g -o lib/init/core_t_extension.o lib/init/core_t_extension.s
Building lib/init/core_vec.o with action:
  $AS $ASFLAGS -o $TARGET $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-as -g -o lib/init/core_vec.o lib/init/core_vec.s
Building lib/init/crt0.o with action:
  $AS $ASFLAGS -o $TARGET $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-as -g -o lib/init/crt0.o lib/init/crt0.s
lib/init/crt0.s: Assembler messages:
lib/init/crt0.s:9: Error: can't open core_init.h for reading: No such file or directory
lib/init/crt0.s:136: Error: unrecognized opcode `sync'
lib/init/crt0.s:147: Error: unrecognized opcode `sync'
scons: *** [lib/init/crt0.o] Error 1

[bdbaddog]

Try running this command manually

opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-as -g -o lib/init/crt0.o lib/init/crt0.s

Is there a core_init.h header file anywhere in your tree or in your toolchain's tree?

[mwichmann]

Definitely making progress, a header-include problem should just require adding to the right SCons construction variable. @bdbaddog - is $CPPATH applied to assembler, too?

[zhajio1988]

@bdbaddog

(myenv) lushan: /ssd_fes/jiongz/desktop/github/sifive/scons_demo$ /opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-as -g -o lib/init/crt0.o lib/init/crt0.s
lib/init/crt0.s: Assembler messages:
lib/init/crt0.s:9: Error: can't open core_init.h for reading: No such file or directory
lib/init/crt0.s:136: Error: unrecognized opcode `sync'
lib/init/crt0.s:147: Error: unrecognized opcode `sync'

Actually, I've been using gcc to compile .s files, and I don't have this problem with gcc.

[zhajio1988]

I changed to scons flow from an old makefile that had the following code in it.

CC      = ${TOOL_EXTENSION}/riscv64-unknown-elf-gcc
AS      = ${TOOL_EXTENSION}/riscv64-unknown-elf-as
LINK    = ${TOOL_EXTENSION}/riscv64-unknown-elf-ld
OBJDUMP = ${TOOL_EXTENSION}/riscv64-unknown-elf-objdump
OBJCOPY = ${TOOL_EXTENSION}/riscv64-unknown-elf-objcopy
CONVERT	=../tests/bin/Srec2vmem
%.o : %.c
	${CC} -c ${CFLAGS} -o $@ $<

%.o : %.s
	${CC} -c ${CFLAGS} -o $@ $<

%.o : %.S
	${CC} -c ${CFLAGS} -o $@ $<

${FILE}.elf : ${OBJECTS} linker.lcf
	${CC} ${LINKFLAGS} ${LINKLIBS} ${OBJECTS} -o $@ -lm 

What you can look at is the .s file compiled with riscv64-unknown-elf-gcc

[bdbaddog]

Try adding this at line 160 in your SConstruct
env['ASCOM'] = env['ASPPCOM']

That should change the crt0.s compile line to:
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -g -Ilib/clib -Ilib/newlib_wrap -Ilib/init -c -o lib/init/crt0.o lib/init/crt0.s

Which I think should work..

For files named .s, .asm, .ASM SCons will run assembler without specifying preprocessor directives on the command line.
For files named .S, .spp, .SPP, .sx SCons will specify those flags including -I's

The change above tells SCons to apply the preprocessing flags (defines, include paths) to the .s, .asm, .ASM suffixed files.

Note if you're on a case-insensitve filesystem remove the .S file from the list which would be preprocessed.

[zhajio1988]

@bdbaddog

> Building lib/clib/fputc.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -o lib/clib/fputc.o -c -O1 -g -Wall -Ilib/clib -Ilib/newlib_wrap -Ilib/init lib/clib/fputc.c
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/riscv64-unknown-elf/include/stdio.h: In function 'fputc':
lib/clib/fputc.c:19:1: warning: control reaches end of non-void function [-Wreturn-type]
   19 | }
      | ^
Building lib/clib/intc.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -o lib/clib/intc.o -c -O1 -g -Wall -Ilib/clib -Ilib/newlib_wrap -Ilib/init lib/clib/intc.c
lib/clib/intc.c: In function 'ck_intc_init':
lib/clib/intc.c:9:34: warning: initialization of 'int *' from 'int' makes pointer from integer without a cast [-Wint-conversion]
    9 | #define APB_BASE                 0x10000000
      |                                  ^~~~~~~~~~
lib/clib/intc.c:15:17: note: in expansion of macro 'APB_BASE'
   15 |     int *picr = APB_BASE;
      |                 ^~~~~~~~
lib/clib/intc.c:10:34: warning: initialization of 'int *' from 'int' makes pointer from integer without a cast [-Wint-conversion]
   10 | #define INTC_BASE                0x10010000
      |                                  ^~~~~~~~~~
lib/clib/intc.c:19:22: note: in expansion of macro 'INTC_BASE'
   19 |         int *piser = INTC_BASE + 0x10;
      |                      ^~~~~~~~~
Building lib/clib/uart.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -o lib/clib/uart.o -c -O1 -g -Wall -Ilib/clib -Ilib/newlib_wrap -Ilib/init lib/clib/uart.c
lib/clib/uart.c: In function 'ck_uart_status':
lib/clib/uart.c:203:18: warning: 'uart_lsr' is used uninitialized in this function [-Wuninitialized]
  203 |     if (uart_lsr & CK_LSR_TEMT)
      |                  ^
Building lib/clib/vtimer.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -o lib/clib/vtimer.o -c -O1 -g -Wall -Ilib/clib -Ilib/newlib_wrap -Ilib/init lib/clib/vtimer.c
lib/clib/vtimer.c: In function 'sim_end':
lib/clib/vtimer.c:21:12: warning: assignment to 'int *' from 'unsigned int' makes pointer from integer without a cast [-Wint-conversion]
   21 |   END_ADDR = 0xA001FF48;
      |            ^
lib/clib/vtimer.c:24:13: warning: unsigned conversion from 'long int' to 'unsigned int' changes value from '18324075042' to '1144205858' [-Woverflow]
   24 |   END_DATA= 0x444333222;
      |             ^~~~~~~~~~~
Building lib/newlib_wrap/__dtostr.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -o lib/newlib_wrap/__dtostr.o -c -O1 -g -Wall -Ilib/clib -Ilib/newlib_wrap -Ilib/init lib/newlib_wrap/__dtostr.c
Building lib/newlib_wrap/__isinf.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -o lib/newlib_wrap/__isinf.o -c -O1 -g -Wall -Ilib/clib -Ilib/newlib_wrap -Ilib/init lib/newlib_wrap/__isinf.c
Building lib/newlib_wrap/__isnan.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -o lib/newlib_wrap/__isnan.o -c -O1 -g -Wall -Ilib/clib -Ilib/newlib_wrap -Ilib/init lib/newlib_wrap/__isnan.c
Building lib/newlib_wrap/__lltostr.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -o lib/newlib_wrap/__lltostr.o -c -O1 -g -Wall -Ilib/clib -Ilib/newlib_wrap -Ilib/init lib/newlib_wrap/__lltostr.c
Building lib/newlib_wrap/__ltostr.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -o lib/newlib_wrap/__ltostr.o -c -O1 -g -Wall -Ilib/clib -Ilib/newlib_wrap -Ilib/init lib/newlib_wrap/__ltostr.c
Building lib/newlib_wrap/__v_printf.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -o lib/newlib_wrap/__v_printf.o -c -O1 -g -Wall -Ilib/clib -Ilib/newlib_wrap -Ilib/init lib/newlib_wrap/__v_printf.c
Building lib/newlib_wrap/fprintf.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -o lib/newlib_wrap/fprintf.o -c -O1 -g -Wall -Ilib/clib -Ilib/newlib_wrap -Ilib/init lib/newlib_wrap/fprintf.c
Building lib/newlib_wrap/getc.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -o lib/newlib_wrap/getc.o -c -O1 -g -Wall -Ilib/clib -Ilib/newlib_wrap -Ilib/init lib/newlib_wrap/getc.c
Building lib/newlib_wrap/getchar.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -o lib/newlib_wrap/getchar.o -c -O1 -g -Wall -Ilib/clib -Ilib/newlib_wrap -Ilib/init lib/newlib_wrap/getchar.c
Building lib/newlib_wrap/printf.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -o lib/newlib_wrap/printf.o -c -O1 -g -Wall -Ilib/clib -Ilib/newlib_wrap -Ilib/init lib/newlib_wrap/printf.c
Building lib/newlib_wrap/putc.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -o lib/newlib_wrap/putc.o -c -O1 -g -Wall -Ilib/clib -Ilib/newlib_wrap -Ilib/init lib/newlib_wrap/putc.c
Building lib/newlib_wrap/putchar.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -o lib/newlib_wrap/putchar.o -c -O1 -g -Wall -Ilib/clib -Ilib/newlib_wrap -Ilib/init lib/newlib_wrap/putchar.c
Building lib/newlib_wrap/puts.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -o lib/newlib_wrap/puts.o -c -O1 -g -Wall -Ilib/clib -Ilib/newlib_wrap -Ilib/init lib/newlib_wrap/puts.c
Building lib/newlib_wrap/snprintf.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -o lib/newlib_wrap/snprintf.o -c -O1 -g -Wall -Ilib/clib -Ilib/newlib_wrap -Ilib/init lib/newlib_wrap/snprintf.c
Building lib/newlib_wrap/sprintf.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -o lib/newlib_wrap/sprintf.o -c -O1 -g -Wall -Ilib/clib -Ilib/newlib_wrap -Ilib/init lib/newlib_wrap/sprintf.c
Building lib/newlib_wrap/vfprintf.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -o lib/newlib_wrap/vfprintf.o -c -O1 -g -Wall -Ilib/clib -Ilib/newlib_wrap -Ilib/init lib/newlib_wrap/vfprintf.c
Building lib/newlib_wrap/vprintf.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -o lib/newlib_wrap/vprintf.o -c -O1 -g -Wall -Ilib/clib -Ilib/newlib_wrap -Ilib/init lib/newlib_wrap/vprintf.c
Building lib/newlib_wrap/vsnprintf.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -o lib/newlib_wrap/vsnprintf.o -c -O1 -g -Wall -Ilib/clib -Ilib/newlib_wrap -Ilib/init lib/newlib_wrap/vsnprintf.c
Building lib/newlib_wrap/vsprintf.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -o lib/newlib_wrap/vsprintf.o -c -O1 -g -Wall -Ilib/clib -Ilib/newlib_wrap -Ilib/init lib/newlib_wrap/vsprintf.c
Building hello_world.o with action:
  $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCCOMCOM $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -o hello_world.o -c -O1 -g -Wall -Ilib/clib -Ilib/newlib_wrap -Ilib/init hello_world.c
hello_world.c: In function 'main':
hello_world.c:39:1: warning: this 'else' clause does not guard... [-Wmisleading-indentation]
   39 | else
      | ^~~~
hello_world.c:41:3: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'else'
   41 |   printf("after ASM c is changed to %d!\n",c);
      |   ^~~~~~
Building lib/init/core_cp0.o with action:
  $CC $ASPPFLAGS $CPPFLAGS $_CPPDEFFLAGS $_CPPINCFLAGS -c -o $TARGET $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -g -Ilib/clib -Ilib/newlib_wrap -Ilib/init -c -o lib/init/core_cp0.o lib/init/core_cp0.s
Building lib/init/core_ifu.o with action:
  $CC $ASPPFLAGS $CPPFLAGS $_CPPDEFFLAGS $_CPPINCFLAGS -c -o $TARGET $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -g -Ilib/clib -Ilib/newlib_wrap -Ilib/init -c -o lib/init/core_ifu.o lib/init/core_ifu.s
Building lib/init/core_l2c.o with action:
  $CC $ASPPFLAGS $CPPFLAGS $_CPPDEFFLAGS $_CPPINCFLAGS -c -o $TARGET $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -g -Ilib/clib -Ilib/newlib_wrap -Ilib/init -c -o lib/init/core_l2c.o lib/init/core_l2c.s
Building lib/init/core_lsu.o with action:
  $CC $ASPPFLAGS $CPPFLAGS $_CPPDEFFLAGS $_CPPINCFLAGS -c -o $TARGET $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -g -Ilib/clib -Ilib/newlib_wrap -Ilib/init -c -o lib/init/core_lsu.o lib/init/core_lsu.s
Building lib/init/core_mmu.o with action:
  $CC $ASPPFLAGS $CPPFLAGS $_CPPDEFFLAGS $_CPPINCFLAGS -c -o $TARGET $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -g -Ilib/clib -Ilib/newlib_wrap -Ilib/init -c -o lib/init/core_mmu.o lib/init/core_mmu.s
Building lib/init/core_plic.o with action:
  $CC $ASPPFLAGS $CPPFLAGS $_CPPDEFFLAGS $_CPPINCFLAGS -c -o $TARGET $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -g -Ilib/clib -Ilib/newlib_wrap -Ilib/init -c -o lib/init/core_plic.o lib/init/core_plic.s
Building lib/init/core_t_extension.o with action:
  $CC $ASPPFLAGS $CPPFLAGS $_CPPDEFFLAGS $_CPPINCFLAGS -c -o $TARGET $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -g -Ilib/clib -Ilib/newlib_wrap -Ilib/init -c -o lib/init/core_t_extension.o lib/init/core_t_extension.s
Building lib/init/core_vec.o with action:
  $CC $ASPPFLAGS $CPPFLAGS $_CPPDEFFLAGS $_CPPINCFLAGS -c -o $TARGET $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -g -Ilib/clib -Ilib/newlib_wrap -Ilib/init -c -o lib/init/core_vec.o lib/init/core_vec.s
Building lib/init/crt0.o with action:
  $CC $ASPPFLAGS $CPPFLAGS $_CPPDEFFLAGS $_CPPINCFLAGS -c -o $TARGET $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -g -Ilib/clib -Ilib/newlib_wrap -Ilib/init -c -o lib/init/crt0.o lib/init/crt0.s
Building lib/init/stress_inst.o with action:
  $CC $ASPPFLAGS $CPPFLAGS $_CPPDEFFLAGS $_CPPINCFLAGS -c -o $TARGET $SOURCES
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -g -Ilib/clib -Ilib/newlib_wrap -Ilib/init -c -o lib/init/stress_inst.o lib/init/stress_inst.s
Building build/main.elf with action:
  $LINK -o $TARGET $LINKFLAGS $__RPATH $SOURCES $_LIBDIRFLAGS $_LIBFLAGS
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/riscv64-unknown-elf-gcc -o build/main.elf -nostartfiles -lc -lgcc -lm -T ./lib/init/linker.lcf -march=rv64imafdcv_zicbom_zicbop_zicboz_zicond1p0_zihintntl0p2_zihintpause_zawrs_zfa0p1_zfbfmin0p8_zfh_zca_zcb_zcd_zba_zbb_zbc_zbs_zvfbfmin0p8_zvfbfwma0p8_svinval_svpbmt_xtheadc_xtheadvdot -mabi=lp64d -mtune=c920 lib/clib/fputc.o lib/clib/intc.o lib/clib/uart.o lib/clib/vtimer.o lib/newlib_wrap/__dtostr.o lib/newlib_wrap/__isinf.o lib/newlib_wrap/__isnan.o lib/newlib_wrap/__lltostr.o lib/newlib_wrap/__ltostr.o lib/newlib_wrap/__v_printf.o lib/newlib_wrap/fprintf.o lib/newlib_wrap/getc.o lib/newlib_wrap/getchar.o lib/newlib_wrap/printf.o lib/newlib_wrap/putc.o lib/newlib_wrap/putchar.o lib/newlib_wrap/puts.o lib/newlib_wrap/snprintf.o lib/newlib_wrap/sprintf.o lib/newlib_wrap/vfprintf.o lib/newlib_wrap/vprintf.o lib/newlib_wrap/vsnprintf.o lib/newlib_wrap/vsprintf.o hello_world.o lib/init/core_cp0.o lib/init/core_ifu.o lib/init/core_l2c.o lib/init/core_lsu.o lib/init/core_mmu.o lib/init/core_plic.o lib/init/core_t_extension.o lib/init/core_vec.o lib/init/crt0.o lib/init/stress_inst.o
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/../lib/gcc/riscv64-unknown-elf/10.4.0/../../../../riscv64-unknown-elf/bin/ld: /opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/../lib/gcc/riscv64-unknown-elf/10.4.0/../../../../riscv64-unknown-elf/lib/rv64imafdcv_zfh_xtheadc/lp64d/crt0.o: in function `_start':
(.text+0x0): undefined reference to `__global_pointer$'
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/../lib/gcc/riscv64-unknown-elf/10.4.0/../../../../riscv64-unknown-elf/bin/ld: (.text+0x8): undefined reference to `_edata'
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/../lib/gcc/riscv64-unknown-elf/10.4.0/../../../../riscv64-unknown-elf/bin/ld: (.text+0x10): undefined reference to `_end'
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/../lib/gcc/riscv64-unknown-elf/10.4.0/../../../../riscv64-unknown-elf/bin/ld: (.text+0x32): undefined reference to `__libc_init_array'
/opt/picocom/ThirdParty_Libs/T-head/C920_R2S0P21/C920_R2S0_manuals_and_tools/manuals_and_tools/08_toolchain_900_series_cpu_toolchain/V2.8.0/Xuantie-900-gcc-elf-newlib-x86_64-V2.8.0/bin/../lib/gcc/riscv64-unknown-elf/10.4.0/../../../../riscv64-unknown-elf/bin/ld: (.text+0x44): undefined reference to `exit'
collect2: error: ld returned 1 exit status
scons: *** [build/main.elf] Error 1