2 files changed, 60 insertions, 2 deletions

diff --git a/sys/arm/at91/at91rm92reg.h b/sys/arm/at91/at91rm92reg.h
index 0c4473b63b1e..7a26339b7393 100644
--- a/sys/arm/at91/at91rm92reg.h
+++ b/sys/arm/at91/at91rm92reg.h
@@ -341,4 +341,44 @@
 
 #define AT91C_MASTER_CLOCK	60000000
 
+/* SDRAMC */
+
+#define AT91RM92_SDRAMC_BASE	0xfffff90
+#define AT91RM92_SDRAMC_MR	0x00
+#define AT91RM92_SDRAMC_MR_MODE_NORMAL	0
+#define AT91RM92_SDRAMC_MR_MODE_NOP	1
+#define AT91RM92_SDRAMC_MR_MODE_PRECHARGE 2
+#define AT91RM92_SDRAMC_MR_MODE_LOAD_MODE_REGISTER 3
+#define AT91RM92_SDRAMC_MR_MODE_REFRESH	4
+#define AT91RM92_SDRAMC_MR_DBW_16	0x10
+#define AT91RM92_SDRAMC_TR	0x04
+#define AT91RM92_SDRAMC_CR	0x08
+#define AT91RM92_SDRAMC_CR_NC_8		0x0
+#define AT91RM92_SDRAMC_CR_NC_9		0x1
+#define AT91RM92_SDRAMC_CR_NC_10	0x2
+#define AT91RM92_SDRAMC_CR_NC_11	0x3
+#define AT91RM92_SDRAMC_CR_NC_MASK	0x00000003
+#define AT91RM92_SDRAMC_CR_NR_11	0x0
+#define AT91RM92_SDRAMC_CR_NR_12	0x4
+#define AT91RM92_SDRAMC_CR_NR_13	0x8
+#define AT91RM92_SDRAMC_CR_NR_RES	0xc
+#define AT91RM92_SDRAMC_CR_NR_MASK	0x0000000c
+#define AT91RM92_SDRAMC_CR_NB_2		0x00
+#define AT91RM92_SDRAMC_CR_NB_4		0x10
+#define AT91RM92_SDRAMC_CR_NB_MASK	0x00000010
+#define AT91RM92_SDRAMC_CR_NCAS_MASK	0x00000060
+#define AT91RM92_SDRAMC_CR_TWR_MASK	0x00000780
+#define AT91RM92_SDRAMC_CR_TRC_MASK	0x00007800
+#define AT91RM92_SDRAMC_CR_TRP_MASK	0x00078000
+#define AT91RM92_SDRAMC_CR_TRCD_MASK	0x00780000
+#define AT91RM92_SDRAMC_CR_TRAS_MASK	0x07800000
+#define AT91RM92_SDRAMC_CR_TXSR_MASK	0x78000000
+#define AT91RM92_SDRAMC_SRR	0x0c
+#define AT91RM92_SDRAMC_LPR	0x10
+#define AT91RM92_SDRAMC_IER	0x14
+#define AT91RM92_SDRAMC_IDR	0x18
+#define AT91RM92_SDRAMC_IMR	0x1c
+#define AT91RM92_SDRAMC_ISR	0x20
+#define AT91RM92_SDRAMC_IER_RES	0x1
+
 #endif /* AT91RM92REG_H_ */
diff --git a/sys/arm/at91/kb920x_machdep.c b/sys/arm/at91/kb920x_machdep.c
index 18301c4fd4b6..da6c6a6365fd 100644
--- a/sys/arm/at91/kb920x_machdep.c
+++ b/sys/arm/at91/kb920x_machdep.c
@@ -182,6 +182,24 @@ static const struct pmap_devmap kb920x_devmap[] = {
 extern vm_offset_t ksym_start, ksym_end;
 #endif
 
+static int
+board_init(void)
+{
+	uint32_t memsize;
+	uint32_t *SDRAMC = (uint32_t *)(AT91RM92_BASE + AT91RM92_SDRAMC_BASE);
+	uint32_t cr, mr;
+	int banks, rows, cols, bw; /* log2 size */
+	
+	cr = SDRAMC[AT91RM92_SDRAMC_CR / 4];
+	mr = SDRAMC[AT91RM92_SDRAMC_MR / 4];
+	bw = (mr & AT91RM92_SDRAMC_MR_DBW_16) ? 1 : 2;
+	banks = (cr & AT91RM92_SDRAMC_CR_NB_4) ? 2 : 1;
+	rows = ((cr & AT91RM92_SDRAMC_CR_NR_MASK) >> 2) + 11;
+	cols = (cr & AT91RM92_SDRAMC_CR_NC_MASK) + 8;
+	memsize = 1 << (cols + rows + banks + bw);
+	return (memsize);
+}
+
 void *
 initarm(void *arg, void *arg2)
 {
@@ -192,7 +210,7 @@ initarm(void *arg, void *arg2)
 	vm_offset_t afterkern;
 	int i = 0;
 	uint32_t fake_preload[35];
-	uint32_t memsize = 32 * 1024 * 1024;
+	uint32_t memsize;
 	vm_offset_t lastaddr;
 #ifdef DDB
 	vm_offset_t zstart = 0, zend = 0;
@@ -341,7 +359,7 @@ initarm(void *arg, void *arg2)
 	cpu_tlb_flushID();
 	cpu_domains(DOMAIN_CLIENT << (PMAP_DOMAIN_KERNEL*2));
 	cninit();
-
+	memsize = board_init();
 	/*
 	 * Pages were allocated during the secondary bootstrap for the
 	 * stacks for different CPU modes.