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-rw-r--r--board/zylonite/lowlevel_init.S149
1 files changed, 129 insertions, 20 deletions
diff --git a/board/zylonite/lowlevel_init.S b/board/zylonite/lowlevel_init.S
index 54c2adf..4d62be5 100644
--- a/board/zylonite/lowlevel_init.S
+++ b/board/zylonite/lowlevel_init.S
@@ -39,6 +39,16 @@ DRAM_SIZE: .long CFG_DRAM_SIZE
.endm
+.macro wait time
+ ldr r2, =OSCR
+ mov r3, #0
+ str r3, [r2]
+0:
+ ldr r3, [r2]
+ cmp r3, \time
+ bls 0b
+.endm
+
/*
* Memory setup
*/
@@ -48,7 +58,7 @@ lowlevel_init:
/* Set up GPIO pins first ----------------------------------------- */
mov r10, lr
- /* GPIO41, 42, 43, 44, 45, 46, 47, 48 */
+ /* Configure GPIO Pins 41 - 48 as UART1 / altern. Fkt. 2 */
ldr r0, =0x40E10438 @ GPIO41 FFRXD
ldr r1, =0x802
str r1, [r0]
@@ -82,7 +92,7 @@ lowlevel_init:
str r1, [r0]
/* tebrandt - ASCR, clear the RDH bit */
- ldr r0, =ASCR
+ ldr r0, =ASCR
ldr r1, [r0]
bic r1, r1, #0x80000000
str r1, [r0]
@@ -101,16 +111,18 @@ lowlevel_init:
/* FIXME: can be optimized later */
/* ---------------------------------------------------------------- */
- ldr r3, =OSCR /* reset the OS Timer Count to zero */
- mov r2, #0
- str r2, [r3]
- ldr r4, =0x300 /* really 0x2E1 is about 200usec, */
- /* so 0x300 should be plenty */
-1:
- ldr r2, [r3]
- cmp r4, r2
- bgt 1b
-
+ /* mk: replaced with wait macro */
+/* ldr r3, =OSCR /\* reset the OS Timer Count to zero *\/ */
+/* mov r2, #0 */
+/* str r2, [r3] */
+/* ldr r4, =0x300 /\* really 0x2E1 is about 200usec, *\/ */
+/* /\* so 0x300 should be plenty *\/ */
+/* 1: */
+/* ldr r2, [r3] */
+/* cmp r4, r2 */
+/* bgt 1b */
+ wait #300
+
mem_init:
/* configure the MEMCLKCFG register */
@@ -209,8 +221,12 @@ mem_init:
str r2, [r1]
ldr r2, [r1]
- /* DDR Read-Strobe Delay Calibration */
- /* bl ddr_calibration */
+ /* Hardware DDR Read-Strobe Delay Calibration */
+ ldr r0, =DDR_HCAL @ DDR_HCAL
+ ldr r1, =0x803ffc07 @ the offset is correct? -SC
+ str r1, [r0]
+ wait #5
+ ldr r1, [r0]
/* Here we assume the hardware calibration alwasy be successful. -SC */
/* Set DMCEN bit in MDCNFG Register */
@@ -220,10 +236,12 @@ mem_init:
str r1, [r0]
/* scrub/init SDRAM if enabled/present */
- ldr r11, =0xa0000000 //RAM_BASE // base address of SDRAM
- ldr r12, =0x04000000 // size of memory to scrub
- mov r8,r12 // save DRAM size
- mov r0, #0 // scrub with 0x0000:0000
+/* ldr r11, =0xa0000000 /\* base address of SDRAM (CFG_DRAM_BASE) *\/ */
+/* ldr r12, =0x04000000 /\* size of memory to scrub (CFG_DRAM_SIZE) *\/ */
+/* mov r8,r12 /\* save DRAM size (mk: why???) *\/ */
+ ldr r8, =0xa0000000 /* base address of SDRAM (CFG_DRAM_BASE) */
+ ldr r9, =0x04000000 /* size of memory to scrub (CFG_DRAM_SIZE) */
+ mov r0, #0 /* scrub with 0x0000:0000 */
mov r1, #0
mov r2, #0
mov r3, #0
@@ -232,8 +250,8 @@ mem_init:
mov r6, #0
mov r7, #0
10: /* fastScrubLoop */
- subs r12, r12, #32 // 32 bytes/line
- stmia r11!, {r0-r7}
+ subs r9, r9, #32 // 32 bytes/line
+ stmia r8!, {r0-r7}
beq 15f
b 10b
@@ -264,3 +282,94 @@ mem_init:
endlowlevel_init:
mov pc, lr
+
+
+/*
+@********************************************************************************
+@ DDR calibration
+@
+@ This function is used to calibrate DQS delay lines.
+@ Monahans supports three ways to do it. One is software
+@ calibration. Two is hardware calibration. Three is hybrid
+@ calibration.
+@
+@ TBD
+@ -SC
+ddr_calibration:
+
+ @ Case 1: Write the correct delay value once
+ @ Configure DDR_SCAL Register
+ ldr r0, =DDR_SCAL @ DDR_SCAL
+q ldr r1, =0xaf2f2f2f
+ str r1, [r0]
+ ldr r1, [r0]
+*/
+/* @ Case 2: Software Calibration
+ @ Write test pattern to memory
+ ldr r5, =0x0faf0faf @ Data Pattern
+ ldr r4, =0xa0000000 @ DDR ram
+ str r5, [r4]
+
+ mov r1, =0x0 @ delay count
+ mov r6, =0x0
+ mov r7, =0x0
+ddr_loop1:
+ add r1, r1, =0x1
+ cmp r1, =0xf
+ ble end_loop
+ mov r3, r1
+ mov r0, r1, lsl #30
+ orr r3, r3, r0
+ mov r0, r1, lsl #22
+ orr r3, r3, r0
+ mov r0, r1, lsl #14
+ orr r3, r3, r0
+ orr r3, r3, =0x80000000
+ ldr r2, =DDR_SCAL
+ str r3, [r2]
+
+ ldr r2, [r4]
+ cmp r2, r5
+ bne ddr_loop1
+ mov r6, r1
+ddr_loop2:
+ add r1, r1, =0x1
+ cmp r1, =0xf
+ ble end_loop
+ mov r3, r1
+ mov r0, r1, lsl #30
+ orr r3, r3, r0
+ mov r0, r1, lsl #22
+ orr r3, r3, r0
+ mov r0, r1, lsl #14
+ orr r3, r3, r0
+ orr r3, r3, =0x80000000
+ ldr r2, =DDR_SCAL
+ str r3, [r2]
+
+ ldr r2, [r4]
+ cmp r2, r5
+ be ddr_loop2
+ mov r7, r2
+
+ add r3, r6, r7
+ lsr r3, r3, =0x1
+ mov r0, r1, lsl #30
+ orr r3, r3, r0
+ mov r0, r1, lsl #22
+ orr r3, r3, r0
+ mov r0, r1, lsl #14
+ orr r3, r3, r0
+ orr r3, r3, =0x80000000
+ ldr r2, =DDR_SCAL
+
+end_loop:
+
+ @ Case 3: Hardware Calibratoin
+ ldr r0, =DDR_HCAL @ DDR_HCAL
+ ldr r1, =0x803ffc07 @ the offset is correct? -SC
+ str r1, [r0]
+ wait #5
+ ldr r1, [r0]
+ mov pc, lr
+*/