Chetan Nanda wrote:
We have a MIPS-4KEC based SoC and running an older version of U-Boot (1.1.3) on it. It is working perfectly fine. Board has 8MB AMD flash and starting address of that flash is 0xBFC00000 (reset vector for MIPS).
Problem is that we are not able to access full 8MB of flash. Only 0xBFC00000 - 0xBFFFFFFF (4MB) is accessible, as it lies in un-mapped, un-cached region of MIPS. From 0xC0000000 lies in mapped memory area of MIPS.
Now my questions are, creating entry in TLBs is sufficient to access rest of 4MB of flash?
We are running U-Boot on an Raza Micro / AMD / Alchemy Au1200 and part of our board initialization code says :
/* PCMCIA is on a 36 bit physical address. We need to map it into a 32 bit addresses */
write_one_tlb(20, /* index */ 0x01ffe000, /* Pagemask, 16 MB pages */ CFG_PCMCIA_IO_BASE, /* Hi */ 0x3C000017, /* Lo0 */ 0x3C200017); /* Lo1 */
write_one_tlb(21, /* index */ 0x01ffe000, /* Pagemask, 16 MB pages */ CFG_PCMCIA_ATTR_BASE, /* Hi */ 0x3D000017, /* Lo0 */ 0x3D200017); /* Lo1 */
In our case this maps the PCMCIA interface to usable 32 bit addresses just fine, so I'm confident your board init code could map your flash to an aliased address that would allow access to the whole 8 MB of flash.
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