I recorded a debian image on a flash drive. Chose the one that debian-mac-8.6.0-amd64-netinst.iso. I checked it on the computer, the installer is loading normally, but I cannot boot from a flash drive on a Mac. I turn on the laptop, clamp alt, but in the boot menu there is only a disk with a poppy axis, no flash drive, how many I did not expect it to appear. After several overloads, set rEFInd. True, I first set foot, confused rEFInd with rEFIt and set it. It did not work at all: the standard Mac bootloader was loading. Then put rEFInd. Launched the standard installation script. He said that the installed version of the bootloader was detected and recommended that the installer be started from the recovery mode. I booted into the recovery mode, launched the installer. He installed everything, wrote that there were no problems. After the reboot, I saw the rEFInd and the options to boot from a hard disk with MacOs or from a USB stick. I chose the flash drive, but the download did not start. The indicator on the flash drive went out, the inscription appeared on the screen
No bootable device - insert boot disk and press any key
after which the indicator flashed on the flash drive. Pressing different keys caused no reaction. I had to cut down the computer using the power button. Download to Mac Os was normal. After that, I went into the recovery mode and in the terminal executed
csrutil disable
To cut down System Integrity Projection. Then I ran the rEFInd installation script again, but nothing has changed. So how do I install debian on a macbook? Model A1278 (MacBook Pro 13, it seems 2011)