Question

我正在使用带有交叉编译器的Xilinx SDK作为aarch64-none-elf-gcc 我正在我的程序中加载一个共享库，我收到错误

Building target: fsbl.elf
Invoking: ARM v8 gcc linker
aarch64-none-elf-gcc -L"/proj/ssw_xhd/boot/balakrish/workspace/hello_world/Debug" -Lwrk/released/2017.3/GA/2017.3_1005_1/installs/lin64/SDK/2017.3/gnu/aarch64/lin/aarch64-none/bin/../lib/gcc/aarch64-none-elf/6.2.1/../../../../aarch64-none-elf/bin/ld -Wl,-T -Wl,../src/lscript.ld -L../../fsbl_bsp/psu_cortexa53_0/lib -o "fsbl.elf"  ./src/psu_init.o ./src/xfsbl_authentication.o ./src/xfsbl_board.o ./src/xfsbl_bs.o ./src/xfsbl_csu_dma.o ./src/xfsbl_dfu_util.o ./src/xfsbl_exit.o ./src/xfsbl_handoff.o ./src/xfsbl_hooks.o ./src/xfsbl_image_header.o ./src/xfsbl_initialization.o ./src/xfsbl_main.o ./src/xfsbl_misc.o ./src/xfsbl_misc_drivers.o ./src/xfsbl_nand.o ./src/xfsbl_partition_load.o ./src/xfsbl_plpartition_valid.o ./src/xfsbl_qspi.o ./src/xfsbl_rsa_sha.o ./src/xfsbl_sd.o ./src/xfsbl_translation_table.o ./src/xfsbl_usb.o   -lhello -Wl,--start-group,-lxil,-lgcc,-lc,--end-group -Wl,--start-group,-lxilffs,-lxil,-lgcc,-lc,--end-group -Wl,--start-group,-lxilsecure,-lxil,-lgcc,-lc,--end-group -Wl,--start-group,-lxilpm,-lxil,-lgcc,-lc,--end-group -n
/tmp/ccjtx6CQ.ltrans0.ltrans.o: In function `main':
<artificial>:(.text.startup+0x18c): undefined reference to `dlopen'
<artificial>:(.text.startup+0x18c): relocation truncated to fit: R_AARCH64_CALL26 against undefined symbol `dlopen'
<artificial>:(.text.startup+0x19c): undefined reference to `dlsym'
<artificial>:(.text.startup+0x19c): relocation truncated to fit: R_AARCH64_CALL26 against undefined symbol `dlsym'
<artificial>:(.text.startup+0x1a4): undefined reference to `library_function'
<artificial>:(.text.startup+0x1a4): relocation truncated to fit: R_AARCH64_CALL26 against undefined symbol `library_function'
<artificial>:(.text.startup+0x1ac): undefined reference to `dlclose'
<artificial>:(.text.startup+0x1ac): relocation truncated to fit: R_AARCH64_CALL26 against undefined symbol `dlclose'
collect2: error: ld returned 1 exit status
make: *** [fsbl.elf] Error 1

最后我的问题是如何在交叉编译中加载-ldl 如果我在C / C ++ Build settings-.libraries-＆gt;库路径中使用-ldl。我收到错误

/wrk/released/2017.3/GA/2017.3_1005_1/installs/lin64/SDK/2017.3/gnu/aarch64/lin/aarch64-none/bin/../lib/gcc/aarch64-none-elf/6.2.1/../../../../aarch64-none-elf/bin/ld: cannot find -ldl
collect2: error: ld returned 1 exit status
make: *** [fsbl.elf] Error 1

Answer 1

你答案的不同部分似乎有冲突。

dlopen，dlsym和朋友用于从文件系统上的其他文件加载代码。换句话说，这些函数与在运行时从目标平台文件系统和操作系统上可用的库加载代码有关。

在交叉编译的情况下，工具链需要提供具有这些功能的实现的库（libdl.so或libdl.a）。工具链提供具有相关操作系统调用的代码，以使用代码打开文件，将其映射到内存并将其链接到正在运行的程序中。

冲突发挥作用的地方。你提到的工具链似乎是裸机工具链。换句话说，这是一个直接在芯片上运行代码的工具链，没有操作系统。如果您没有操作系统，那么显然您不能使用它来在运行时加载更多代码。

考虑到这一点，应该很明显为什么工具链不能为您提供合适的libdl.a实现。它不能在平台上一般实现。

如何在SDK中的交叉编译器中访问-ldl

1 个答案: