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authorRafaël Carré <rafael.carre@gmail.com>2009-06-13 23:52:13 +0000
committerRafaël Carré <rafael.carre@gmail.com>2009-06-13 23:52:13 +0000
commit02a53fd809b46ef60555c55d550e6754c46c4c69 (patch)
treea31ec451bd4fb32af67b128f89741bdc5789bb43
parent2bb7c422ea78a93cae53e2f9746559fa0bf7ee7b (diff)
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Sansa AMS: add a comment in sdram_init(), and use inline asm to set the SDRAM mode register
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@21282 a1c6a512-1295-4272-9138-f99709370657
-rw-r--r--firmware/target/arm/as3525/system-as3525.c8
1 files changed, 5 insertions, 3 deletions
diff --git a/firmware/target/arm/as3525/system-as3525.c b/firmware/target/arm/as3525/system-as3525.c
index 60fe703..ecb9736 100644
--- a/firmware/target/arm/as3525/system-as3525.c
+++ b/firmware/target/arm/as3525/system-as3525.c
@@ -209,9 +209,11 @@ static void sdram_init(void)
MPMC_DYNAMIC_CONTROL = 0x82; /* SDRAM MODE, MPMCCLKOUT runs continuously */
- /* this part is required, if you know why please explain */
- unsigned int tmp = *(volatile unsigned int*)(0x30000000+0x2300*MEM);
- (void)tmp; /* we just need to read from this location */
+ /* program the SDRAM mode register */
+ /* FIXME: details the exact settings of mode register */
+ asm volatile(
+ "ldr r4, [%0]\n"
+ : : "p"(0x30000000+0x2300*MEM) : "r4");
MPMC_DYNAMIC_CONTROL = 0x2; /* SDRAM NORMAL, MPMCCLKOUT runs continuously */