LinuxQuestions.org - 32 or 64bit EFI

- Linux Mint (https://www.linuxquestions.org/questions/linux-mint-84/)

- - 32 or 64bit EFI (https://www.linuxquestions.org/questions/linux-mint-84/32-or-64bit-efi-4175644325/)

Mid 2007 13" White MacBook. I took HDD out of Inspiron Laptop running Mint 19 64 bit Cinnamon, put it in the MacBook. It boots and runs well, but only sees 3 of the 4GB of RAM. The MacBook has 64bit CPU. everymac.com says that it's serial # indicates it has 64bit EFI. Is EFI on both the HDD and also embedded in the chipset? If in the chipset, how to verify if it is truly 32 or 64bit? Right now I have Mint 18 Cinnamon in it getting the same results. Both drives see all 4GB of RAM when in the Inspiron 1520. I no longer have a drive w/apple on it. Neither drive has MBR.

32bit does not have enough bits to run at 64bit, so you cannot run 64bit on 32bit, but a 64bit can run 32bit.

64 - 32 = 32;
32 - 64 = -32;

why it is not picking up your 4*GB RAM, a few commands to see what it sees.

Code:

cat /proc/meminfo | grep MemTotal

free | awk 'FNR==2{print $2}'

top // just look at it where it says total.

copy paste it back, it might be a math problem in conversion, or not.

The partition table has nothing to do with amount of RAM seen as installed.

By RAM to do mean, size of HDD? Because that is not RAM, RAM is Random Access Memory, whereas HDD is considered storage space, and not Ram, so if you are saying you have 4*GB of space on your HDD, and it is seeing only 3gb out of 4gb.

Code:

sudo parted -l | grep Partition

then look for partition table, to see if it is gpt or MBR.

Which equates to being just silly. Because it is a TB limitation on HDD's and not GB limitation. So now I am more confused than when I started.

Quote:

Originally Posted by BW-userx (Post 5937445)

32bit does not have enough bits to run at 64bit, so you cannot run 64bit on 32bit, but a 64bit can run 32bit.

64 - 32 = 32;
32 - 64 = -32;

The CPU is 64bit. Some MacBooks have 64bit cpu and 32bit EFI. Specs say my MacBook has 64bit CPU and 64bit EFI

Quote:

Originally Posted by BW-userx (Post 5937445)

why it is not picking up your 4*GB RAM, a few commands to see what it sees.

Code:

cat /proc/meminfo | grep MemTotal

free | awk 'FNR==2{print $2}'

top // just look at it where it says total.

copy paste it back, it might be a math problem in conversion, or not.

$ cat /proc/meminfo | grep MemTotal
MemTotal: 3042120 kB

$ free | awk 'FNR==2{print $2}'
3042120

$ top //
top: unknown option '/'

$ top

top - 10:43:53 up 11 min, 1 user, load average: 0.08, 0.54, 0.48
Tasks: 172 total, 2 running, 130 sleeping, 0 stopped, 0 zombie
%Cpu(s): 2.8 us, 0.7 sy, 0.0 ni, 96.5 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st
KiB Mem : 3042120 total, 255852 free, 1329752 used, 1456516 buff/cache
KiB Swap: 3905532 total, 3905532 free, 0 used. 1385692 avail Mem

I booted memtest it indicates 4GB RAM installed

Quote:

Originally Posted by BW-userx (Post 5937445)

The partition table has nothing to do with amount of RAM seen as installed.

By RAM to do mean, size of HDD? Because that is not RAM, RAM is Random Access Memory, whereas HDD is considered storage space, and not Ram, so if you are saying you have 4*GB of space on your HDD, and it is seeing only 3gb out of 4gb.

RAM is the size of memory installed. The HDD is 1 TB

Code:

sudo parted -l | grep Partition

then look for partition table, to see if it is gpt or MBR.[/QUOTE]

$ sudo parted -l | grep Partition
[sudo] password for tom:
Partition Table: msdos

B, 1000204886016 bytes, 1953525168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disklabel type: dos
Disk identifier: 0xe3a7dfc5

Device Boot Start End Sectors Size Id Type
/dev/sda1 * 2048 58593844 58591797 28G 83 Linux
/dev/sda2 58595326 1953330322 1894734997 903.5G 5 Extended
/dev/sda5 58595328 66406399 7811072 3.7G 82 Linux swap / Solaris
/dev/sda6 66408448 1953330322 1886921875 899.8G 83 Linux

Partition 2 does not start on physical sector boundary.

Quote:

Originally Posted by BW-userx (Post 5937445)

Which equates to being just silly. Because it is a TB limitation on HDD's and not GB limitation. So now I am more confused than when I started.

Again, the drive is 1 TB. The Physical Memory installed is 4GB. Apple intentionally limited the OS installed on some 64bit MacBooks to only make 3GB RAM available to the user. The MacBook does not have a BIOS. Since the HDD Mint is on has never had an apple OS on it, is 64bit OS with 64bit EFI I do not understand why it does not see all of the RAM. I am thinking the limitation is set in the Intel chipset.

Can you please provide a link to the everymac.com page that relates directly to your model. Thanks.

https://everymac.com/systems/apple/m...007-specs.html

That's according to the MacBook's serial #

I now see problem. msdos means MBR. When I did the install I did not select MBR. I manually partitioned the drive. In spite of that it is MBR. The MacBook limits anything MBR to 3GB of RAM.

Quote:

Originally Posted by borgward (Post 5937519)

https://everymac.com/systems/apple/m...007-specs.html

That's according to the MacBook's serial #

Thanks. Half-way down that spec:

Quote:

Apple officially supports 2 GB of RAM, but third-parties have been "unofficially" able to upgrade it to 3 GB or 4 GB of RAM (it can hold 4 GB but cannot fully utilize the memory beyond 3 GB due to the same limitation that impacts the "Late 2006" MacBook Pro line).

That links to the following page - https://everymac.com/systems/apple/m...n-details.html - which explains that the Intel chipset in question uses addresses that overlap with memory above 3GiB, thus rendering some or all of that memory inaccessible as RAM.

I suspected the chipset limited usable RAM to 3 GB. Your link clears that up. Supposedly code can be put in GRUB to tell the Mid 2007 MacBook chipset to allow the user to have all the RAM. I doubt that. One user claims 8GB of RAM on a MocBook Pro running linux, but that's a different machine.