I installed openblas in ARMv6 (Raspberry Pi Zero W), and the following library is installed:
$this->bbcode_second_pass_code('', '-rwxr-xr-x 1 root root 2197288 Mar 9 13:23 libopenblas_armv7p-r0.3.9.so')
Checking the architecture, it is really an ARMv7 instead of ARMv6 library:
$this->bbcode_second_pass_code('', '[root@5bf805c78240 lib]# objdump -f libopenblas_armv7p-r0.3.9.so
libopenblas_armv7p-r0.3.9.so: file format elf32-littlearm
architecture: armv7, flags 0x00000150:
HAS_SYMS, DYNAMIC, D_PAGED
start address 0x00015720')