[U-Boot] MMU init code in uboot for MX31 PDK
Hi Magnus/all,
Where does the mmu_init code in the uboot code for mx31 pdk reside? I am looking for things with MMU initialization like setting the actual base, virtual base and the TLB settings.
Can anyone throw light on the same?Thanks in advance!!
-Alfred
2009/6/4 alfred steele alfred.jaquez@gmail.com:
Hi Magnus/all,
Where does the mmu_init code in the uboot code for mx31 pdk reside? I am looking for things with MMU initialization like setting the actual base, virtual base and the TLB settings.
Can anyone throw light on the same?Thanks in advance!!
The MMU is not used in ARM/U-boot, at least not on the i.MX31.
/Magnus
The MMU is not used in ARM/U-boot, at least not on the i.MX31.
I was thinking there has to be a mechnism which defines the phystovirtual mapping table before the kernel starts running in the virtual space and the IO peripherals to access memory space/registers. Redboot does the same, hence i thought u-boot must be doing it somewhere. Please correct me if i am wrong. -Alfred.
2009/6/4 alfred steele alfred.jaquez@gmail.com:
The MMU is not used in ARM/U-boot, at least not on the i.MX31.
I was thinking there has to be a mechnism which defines the phystovirtual mapping table before the kernel starts running in the virtual space and the IO peripherals to access memory space/registers. Redboot does the same, hence i thought u-boot must be doing it somewhere.
That's done by the kernel in the early startup after decompressing.
/Magnus
On Thu, Jun 4, 2009 at 10:51 AM, Magnus Lilja lilja.magnus@gmail.comwrote:
2009/6/4 alfred steele alfred.jaquez@gmail.com:
The MMU is not used in ARM/U-boot, at least not on the i.MX31.
I was thinking there has to be a mechnism which defines the phystovirtual mapping table before the kernel starts running in the virtual space and the IO peripherals to access memory space/registers. Redboot does the same, hence i thought u-boot must be doing it somewhere.
That's done by the kernel in the early startup after decompressing.
/Magnus _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
u-boot needs to initialize the ram, but the MMU isn't needed by either the ram or the rest of the memory mapped I/O. For the imx27 external ram (for CSD0) is located at 0xa0000000 but like the rest of the memory map this doesn't need to be "setup".
thanks, Paul
participants (3)
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alfred steele -
Magnus Lilja -
Paul Thomas