Guillaume Maire

MCF5484 and MMU initialisation

Discussion created by Guillaume Maire on Jul 6, 2009
Latest reply on Jul 15, 2009 by Guillaume Maire

Hi all,


I have a custom MCF5484 board with 128Mb RAM. My development environnement is :

- U-Boot

- Linux 2.6.10

- gcc version 4.2.3 (Sourcery G++ Lite 4.2-125)


Under U-Boot, I'm able to see and use the whole 128Mb.

CONFIG_SDRAM_SIZE is set to 0x8000000 in the Linux configuration. Linux starts with 128Mb (displayed at boot time). When /sbin/init is called, the system freezes. I tried to change the configuration of the MMU in head.S but nothing has changed.

I read that the TLB of the MCF5484 has 32 lines of 1Mb leading to use no more than 32Mb with the MMU.


So, my question is : is there a possibility to use the whole RAM I have on my board (128Mb) with the MCF5484 and the MMU ?

If not, why am I able to use the 5485EVB board with 64Mb of RAM (2.6.25 Linux kernel) ?


Thanks for your help!