Linker Error During BusyBox Compilation

[Kingxukai]

Hi there,
I'm currently encountering a linking error while trying to compile BusyBox on my Ubuntu 20.04 system. I have tried checking for missing libraries, but the issue persists.Here are the details of the error:

First Step

I tried to boot linux with u-boot ,but it failed as the lack of init process.
Here is the output info below:

[    0.179696] platform 502b0000.pinmux: Fixed dependency cycle(s) with /soc/bus@50200000/pinmux@502b0000/jtag-pinmux
[    0.195124] platform 50440000.syscon: Fixed dependency cycle(s) with /soc/bus@50400000/syscon@50440000/clock-controller
[    0.210875] k210-sysctl 50440000.syscon: K210 system controller
[    0.222554] k210-rst 50440000.syscon:reset-controller: K210 reset controller
[    0.230191] 38000000.serial: ttySIF0 at MMIO 0x38000000 (irq = 1, base_baud = 24375000) is a SiFive UART v0
[    0.239278] printk: console [ttySIF0] enabled
[    0.239278] printk: console [ttySIF0] enabled
[    0.247891] printk: bootconsole [sifive0] disabled
[    0.247891] printk: bootconsole [sifive0] disabled
[    0.259842] cacheinfo: Unable to detect cache hierarchy for CPU 0
[    0.268511] spi spi1.0: setup: ignoring unsupported mode bits a00
[    0.274610] i2c_dev: i2c /dev entries driver
[    0.290696] k210-fpioa 502b0000.pinmux: K210 FPIOA pin controller
[    0.332473] mmc_spi spi3.0: SD/MMC host mmc0, no WP, no poweroff, cd polling
[    0.343051] Waiting for root device /dev/mmcblk0p2...
[    0.364506] mmc0: host does not support reading read-only switch, assuming write-enable
[    0.371805] mmc0: new SDHC card on SPI
[    0.377328] mmcblk0: mmc0:0000 SA16G 14.4 GiB 
[    0.416484]  mmcblk0: p1 p2
[    0.434923] VFS: Mounted root (ext2 filesystem) readonly on device 179:2.
[    0.446836] devtmpfs: mounted
[    0.449442] Freeing unused kernel image (initmem) memory: 116K
[    0.454893] This architecture does not have kernel memory protection.
[    0.461327] Run /sbin/init as init process
[    0.465600] Run /etc/init as init process
[    0.475219] Run /bin/init as init process
[    0.478709] Run /bin/sh as init process
[    0.482493] Kernel panic - not syncing: No working init found.  Try passing init= option to kernel. See Linux Documentation/admin-guide/init.rst for guidance.
[    0.496442] SMP: stopping secondary CPUs
[    0.500363] ---[ end Kernel panic - not syncing: No working init found.  Try passing init= option to kernel. See Linux Documentation/admin-guide/init.rst for guidance. ]---

Second

So, I guess may be it is the result of lack of BusyBox which built failed that I skipped before:

$ make SKIP_STRIP=y               
  CC      applets/applets.o                                                
In file included from include/libbb.h:13,                                  
                 from include/busybox.h:8,                                 
                 from applets/applets.c:9:                                 
include/platform.h:164:11: fatal error: byteswap.h: No such file or directory
  164 | # include <byteswap.h>                                             
      |           ^~~~~~~~~~~~                                             
compilation terminated.                                                    
make[1]: *** [scripts/Makefile.build:198: applets/applets.o] Error 1       
make: *** [Makefile:372: applets_dir] Error 2

I find the files it needs

opt/riscv64-uclibc/host/riscv64-buildroot-linux-uclibc/sysroot/usr/lib$ ls
crt1.o  libcrypt.a  libintl.a  libnsl.a     librt.a
libc.a  libdl.a     libm.a     libresolv.a
/opt/riscv64-uclibc/host/riscv64-buildroot-linux-uclibc/sysroot/usr/lib$ sudo find /opt -name byteswap.h                                    
/opt/riscv64-uclibc/host/riscv64-buildroot-linux-uclibc/sysroot/usr/include/byteswap.h

and then check the PATH is set

k210-linux-nommu/busybox$ echo $PATH | grep "/opt/riscv64-uclibc/bin"                                                               
/opt/riscv64-uclibc/bin ...

Third

after that I tried with
k210-linux-nommu/busybox$ make SKIP_STRIP=y CFLAGS="-I/opt/riscv64-uclibc/host/riscv64-buildroot-linux-uclibc/sysroot/usr/include"
but it return with

/opt/riscv64-uclibc/riscv64-buildroot-linux-uclibc/bin/ld.real: cannot find crt1.o: No such file or directory
collect2: error: ld returned 1 exit status
Note: if build needs additional libraries, put them in CONFIG_EXTRA_LDLIBS.
Example: CONFIG_EXTRA_LDLIBS="pthread dl tirpc audit pam"
make: *** [Makefile:718: busybox_unstripped] Error 1 

And it not works with
k210-linux-nommu/busybox$ make SKIP_STRIP=y CFLAGS="-I/opt/riscv64-uclibc/host/riscv64-buildroot-linux-uclibc/sysroot/usr/include" CONFIG_EXTRA_LDLIBS="/opt/riscv64-uclibc/host/riscv64-buildroot-linux-uclibc/sysroot/usr/lib/crt1.o"

still return the error:

/opt/riscv64-uclibc/riscv64-buildroot-linux-uclibc/bin/ld.real: cannot find crt1.o: No such file or directory
collect2: error: ld returned 1 exit status
Note: if build needs additional libraries, put them in CONFIG_EXTRA_LDLIBS.
Example: CONFIG_EXTRA_LDLIBS="pthread dl tirpc audit pam"
make: *** [Makefile:718: busybox_unstripped] Error 1