diff options
Diffstat (limited to 'board')
| -rw-r--r-- | board/zylonite/lowlevel_init.S | 149 |
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 +*/ |