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RE: AT91SAM7SE with external SDRAM
- From: "Chris Zimman" <czimman at bloomberg dot com>
- To: <jc dot caquet at kerlink dot fr>
- Cc: <ecos-discuss at ecos dot sourceware dot org>
- Date: Mon, 20 Aug 2007 08:29:02 -0400
- Subject: RE: [ECOS] AT91SAM7SE with external SDRAM
- References: <20070820101456.GB22488@lunn.ch> <60i8ie$1m4j24@mgcp1.bloomberg.com>
> As soon as SDRAM config has been done at the right place is it enough
to
> change address/size values in mt_arm_at91sam7se512_rom.h/.ldi files so
> that ECOS uses SDRAM ?
> Why not to configure SDRAM in hal_hardware_init that seems to be the
first > C code section called from vectors.S, we don't have any skills
in ARM
> assembly here...
Most of the platforms use a templated setup in hal_platform_setup.h, eg.
packages/hal/arm/at91/[your
platform]/current/include/hal_platform_setup.h
[...]
_InitMemory:
.long 0x01002529 // 0x01000000, 16MB, 2 cycles after
transfer, // 16-bit, 6 wait states
.long 0x02002121 // 0x02000000, 16MB, 0 cycles after
transfer, // 16-bit, 1 wait state
.long 0x20000000 // unused
.long 0x30000000 // unused
.long 0x05002021 // 0x05000000, 1MB, 0 cycles after
transfer, // 16-bit, 1 wait state
(MEC01 on CS4)
.long 0x05102021 // 0x05100000, 1MB, 0 cycles after
transfer, // 16-bit, 1 wait state
(MEC01 on CS5)
.long 0x60000000 // unused
.long 0x70000000 // unused
.long 0x00000001 // REMAP command
.long 0x00000000 // Standard read protocol
.long AT91_EBI // External Bus Interface address
.long 10f // address where to jump
[...]
Figure out what the correct values for the EBI chip selects are for your
platform and then add them here.
Extensive ARM assembly skills are not required, just a little bit of
reading and perhaps stepping through the setup code with a debugger if
things don't go how you're expecting.
--Chris
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