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-rw-r--r--board/impa7/lowlevel_init.S85
1 files changed, 85 insertions, 0 deletions
diff --git a/board/impa7/lowlevel_init.S b/board/impa7/lowlevel_init.S
new file mode 100644
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+/*
+ * Memory Setup stuff - taken from ???
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+
+#include <config.h>
+#include <version.h>
+
+
+/* some parameters for the board */
+
+SYSCON2: .long 0x80001100
+MEMCFG1: .long 0x80000180
+MEMCFG2: .long 0x800001C0
+DRFPR: .long 0x80000200
+
+syscon2_mask: .long 0x00000004
+memcfg1_val: .long 0x160c1414
+memcfg2_mask: .long 0x0000ffff @ only set lower 16 bits
+memcfg2_val: .long 0x00000000 @ upper 16 bits are reserved for CS7 + CS6
+drfpr_val: .long 0x00000081
+/* setting up the memory */
+
+.globl lowlevel_init
+lowlevel_init:
+ /*
+ * DRFPR
+ * 64kHz DRAM refresh
+ */
+ ldr r0, DRFPR
+ ldr r1, drfpr_val
+ str r1, [r0]
+
+ /*
+ * SYSCON2: clear bit 2, DRAM is 32 bits wide
+ */
+ ldr r0, SYSCON2
+ ldr r2, [r0]
+ ldr r1, syscon2_mask
+ bic r2, r2, r1
+ str r2, [r0]
+
+ /*
+ * MEMCFG1
+ * Setting up Keyboard at CS3, 8 Bit, 3 Waitstates
+ * Setting up CS8900 (Ethernet) at CS2, 32 Bit, 5 Waitstates
+ * Setting up flash at CS0 and CS1, 32 Bit, 3 Waitstates
+ */
+ ldr r0, MEMCFG1
+ ldr r1, memcfg1_val
+ str r1, [r0]
+
+ /*
+ * MEMCFG2
+ * Setting up ? with 0
+ *
+ */
+ ldr r0, MEMCFG2
+ ldr r2, [r0]
+ ldr r1, memcfg2_mask
+ bic r2, r2, r1
+ ldr r1, memcfg2_val
+ orr r2, r2, r1
+ str r2, [r0]
+
+ /* everything is fine now */
+ mov pc, lr