After flashing the EFI on my MacBook Air (through MBA Easy Flash and Raspberry Pi) and getting around the startup padlock, I've found my MacBook Air has been incredibly slow in both starting up, booting and waking from sleep. I takes literally 15-20 seconds for it to chime from pressing the power button.
Is this the result of a bad flash? I read on here somewhere that it's recommended that the A1466 use the +3.3V connections, although in my case, I didn't use them (discovered this info AFTER flashing). Could this be the cause of it?
Also what is the function of the switch on the MBA Easy Flash?
The switch on the MBA clip changes the pinout configuration.
MBA Clip Pinout Configuration
Pin 1 of the chip (marked with a small dot) which is CS (Chip Select) goes to pin 24 on the Raspberry Pi.
Pin 2 of the chip which is MISO (Master In Slave Out) goes to pin 21 on the Raspberry Pi.
Pin 3 of the chip which is WP (Write Protect) goes to pin 17 on the Raspberry Pi.
Pin 4 of the chip which is GND (Ground) goes to pin 25 on the Raspberry Pi.
Pin 5 of the chip which is MOSI (Master Out Slave In) goes to pin 19 on the Raspberry Pi.
Pin 6 of the chip which is SCLK (Clock Speed) goes to pin 23 on the Raspberry Pi.
Pin 7 of the chip which is HOLD (Hold) goes to pin 17 in the Raspberry Pi.
Pin 8 of the chip which is VCC (Positive Supply Voltage) goes to pin 17 on the Raspberry Pi (3.3v)
I use a breadboard to gain more 3.3v out. I run the 3.3v from the PI to the breadboard that has a five pin header installed so I end up with extra 3.3v connections for the clip.
I use the above pinout configuration for models A1502 - A1466 - A1465 - A1425 with the switch to the left.
I use the same pinout configuration as above for models A1398 - A1369 - A1370 except I throw the switch to the right.
Some people don’t use the 3.3v for the WP and the HOLD. I use them all the time and never have any issues especially with model 1466 which requires the 3.3v on the WP and HOLD.
Did you flash a changed firmware taken from this machine or it was flashed with firmware from another?
Can you provide an output of 'nvram -p' command in Safe mode? (May be screenshot) Also, can you provide an output for 'diskutil list' command?
I grabbed firmware from the EFI repository on here. I then changed the <model-number> statement to my serial number, as per previous successes with other machines.
I have just done the re-flash using the advised pin configuration and the MacBook Air no longer boots - no startup chime, just a black screen. Have reset the SMC but no change in situation.
Last edit: 8 years 6 months ago by perthdave. Reason: additional info
I attempted to run diagnostics at boot (D key after startup chime) and things were looking hopeful, but only got far as selecting my preferred language and clicking what the equivalent of 'next' was (going off my failing memory here).
After safe booting into the finder, I re-selected the internal hard drive as preferred boot device, but no change for normal boot - progress bar gets about 30% the way through and doesn't go any further.
Option key at restart, selected the recovery partition. Does its 30% progress bar halt, then out of the blue, the voiceover voice rings out "To use English as your main language, press the return key". But what is peculiar about this, is that it hasn't reached the expected Mac OX Utilities screen but remained on the same boot up screen where the progress bar is still stuck at 30%. Pressing return doesn't have any affect either.
Well, the question 'Why it was slow?' still opened. But it looks like memory corruption the problem like this and iTunes encryption kext's problem seems somehow linked together...
Indeed. I'm not entirely sure whether that particular EFI dump on here is verified as working 100%. Can anyone vouch for this? Otherwise, I'm happy to upload my sanitised dump.
I can offer more interesting experiment
perthdave, can you backup your current working firmware and flash a files which allows you to boot into single user mode?
If you are ready to do it, boot the machine into SU mode and mount an EFI partition with command:
diskutil mount /dev/disk0s1
The EFI partition should be mounted in /Volumes/EFI. Interested file: /Volumes/EFI/EFI/APPLE/EXTENSIONS/Firmware.scap. I think it is something like a BIOS cache.
We are trying a firmware from another machine, this file may contains some unique information from previous firmware and that information may be reason for some collisions or distortion inside memory. But we can remove it. I think it is safe... or just rename it. Reboot a computer and let's see what's will happen
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