报错及处理记录

h:/c51/h5toolchain_v1.0_beta6/h5toolchain_v1.0_beta6/gcc/gcc-arm-none-eabi-5.3/bin/../lib/gcc/arm-none-eabi/5.3.1/../../../../arm-none-eabi/lib/armv6-m\libc_nano.a(lib_a-writer.o): In function `_write_r':
writer.c:(.text._write_r+0x18): undefined reference to `_write'
h:/c51/h5toolchain_v1.0_beta6/h5toolchain_v1.0_beta6/gcc/gcc-arm-none-eabi-5.3/bin/../lib/gcc/arm-none-eabi/5.3.1/../../../../arm-none-eabi/lib/armv6-m\libc_nano.a(lib_a-closer.o): In function `_close_r':
closer.c:(.text._close_r+0x12): undefined reference to `_close'
h:/c51/h5toolchain_v1.0_beta6/h5toolchain_v1.0_beta6/gcc/gcc-arm-none-eabi-5.3/bin/../lib/gcc/arm-none-eabi/5.3.1/../../../../arm-none-eabi/lib/armv6-m\libc_nano.a(lib_a-lseekr.o): In function `_lseek_r':
lseekr.c:(.text._lseek_r+0x18): undefined reference to `_lseek'
h:/c51/h5toolchain_v1.0_beta6/h5toolchain_v1.0_beta6/gcc/gcc-arm-none-eabi-5.3/bin/../lib/gcc/arm-none-eabi/5.3.1/../../../../arm-none-eabi/lib/armv6-m\libc_nano.a(lib_a-readr.o): In function `_read_r':
readr.c:(.text._read_r+0x18): undefined reference to `_read'

原因：库内使用某些了c51不支持的函数，比如sscanf、printf等。