[U-Boot] Is it possible to use 2GB or DDR on MPC834x?
Hi Guys!
On my mpc8347 based board I can access 1GB of DDR with mapping 4 of 256MB ranges via IBAT\DBAT registers.
But with the 2 GB of DDR it's impossible to map them with BATs (there are only 8 BATs in the e300 core and the rest 4 of them are already used).
All the mpc83xx examples in the U-boot tree seem to use <=1GB of SDRAM, so they use BATs to map them.
Any suggestions are highly appreciated.
Best regards, Valeriy Glushkov
Valeriy Glushkov wrote:
Hi Guys!
On my mpc8347 based board I can access 1GB of DDR with mapping 4 of 256MB ranges via IBAT\DBAT registers.
But with the 2 GB of DDR it's impossible to map them with BATs (there are only 8 BATs in the e300 core and the rest 4 of them are already used).
All the mpc83xx examples in the U-boot tree seem to use <=1GB of SDRAM, so they use BATs to map them.
Any suggestions are highly appreciated.
Why do you need to access all 2GB from u-boot?
-Scott
Hi,
Why do you need to access all 2GB from u-boot?
I need only to recognize the real memory size and pass the value to Linux.
If I return the real value 2GB from my initdram() U-boot does not like that and resets the board.
Our devices have to support different DDR types and sizes (512/1024/2048 MB), so U-boot is responsible for DDR init and reporting its size to Linux...
From your answer I understand that U-boot does not support >1GB of memory
for MPC83xx. Is it correct?
Best regards, Valeriy Glushkov
----- Original Message ----- From: "Scott Wood" scottwood@freescale.com To: "Valeriy Glushkov" gvv@lstec.com Cc: u-boot@lists.denx.de Sent: 30 ??????? 2008 ?. 18:45 Subject: Re: [U-Boot] Is it possible to use 2GB or DDR on MPC834x?
Valeriy Glushkov wrote:
Hi Guys!
On my mpc8347 based board I can access 1GB of DDR with mapping 4 of 256MB ranges via IBAT\DBAT registers.
But with the 2 GB of DDR it's impossible to map them with BATs (there are only 8 BATs in the e300 core and the rest 4 of them are already used).
All the mpc83xx examples in the U-boot tree seem to use <=1GB of SDRAM, so they use BATs to map them.
Any suggestions are highly appreciated.
Why do you need to access all 2GB from u-boot?
-Scott
Hi All,
The problem has been solved with defining of the following in the board config file: #define CONFIG_VERY_BIG_RAM #define CONFIG_MAX_MEM_MAPPED ((phys_size_t)1024 << 20)
After that Linux recognizes all the DDR memory, while U-boot runs well using the first 1GB of it.
Best regards, Valeriy Glushkov
----- Original Message ----- From: "Valeriy Glushkov" gvv@lstec.com To: u-boot@lists.denx.de Sent: 5 ?????? 2009 ?. 14:09 Subject: Re: [U-Boot] Is it possible to use 2GB of DDR on MPC834x?
Hi,
Why do you need to access all 2GB from u-boot?
I need only to recognize the real memory size and pass the value to Linux.
If I return the real value 2GB from my initdram() U-boot does not like that and resets the board.
Our devices have to support different DDR types and sizes (512/1024/2048 MB), so U-boot is responsible for DDR init and reporting its size to Linux...
From your answer I understand that U-boot does not support >1GB of memory for MPC83xx. Is it correct?
Best regards, Valeriy Glushkov
----- Original Message ----- From: "Scott Wood" scottwood@freescale.com To: "Valeriy Glushkov" gvv@lstec.com Cc: u-boot@lists.denx.de Sent: 30 ??????? 2008 ?. 18:45 Subject: Re: [U-Boot] Is it possible to use 2GB or DDR on MPC834x?
Valeriy Glushkov wrote:
Hi Guys!
On my mpc8347 based board I can access 1GB of DDR with mapping 4 of 256MB ranges via IBAT\DBAT registers.
But with the 2 GB of DDR it's impossible to map them with BATs (there are only 8 BATs in the e300 core and the rest 4 of them are already used).
All the mpc83xx examples in the U-boot tree seem to use <=1GB of SDRAM, so they use BATs to map them.
Any suggestions are highly appreciated.
Why do you need to access all 2GB from u-boot?
-Scott
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Valeriy Glushkov