Initial revision

1 files changed, 877 insertions, 0 deletions

diff --git a/board/eltec/elppc/asm_init.S b/board/eltec/elppc/asm_init.S
new file mode 100644
index 0000000..a5605b7
--- /dev/null
+++ b/board/eltec/elppc/asm_init.S
@@ -0,0 +1,877 @@
+/*
+ * (C) Copyright 2001 ELTEC Elektronik AG
+ * Frank Gottschling <fgottschling@eltec.de>
+ *
+ * ELTEC ELPPC RAM initialization
+ *
+ * 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>
+#include <mpc106.h>
+
+#include <ppc_asm.tmpl>
+#include <ppc_defs.h>
+
+.globl board_asm_init
+board_asm_init:
+
+/*
+ * setup pointer to message block
+ */
+    mflr    r13                 /* save away link register */
+    bl      get_lnk_reg         /* r3=addr of next instruction */
+    subi    r4, r3, 8           /* r4=board_asm_init addr */
+    addi    r29, r4, (MessageBlock-board_asm_init)
+
+/*
+ * dcache_disable
+ */
+    mfspr   r3, HID0
+    li      r4, HID0_DCE
+    andc    r3, r3, r4
+    mr      r2, r3
+    ori     r3, r3, HID0_DCI
+    sync
+    mtspr   HID0, r3
+    mtspr   HID0, r2
+    isync
+    sync
+/*
+ * icache_disable
+ */
+    mfspr   r3, HID0
+    li      r4, 0
+    ori     r4, r4, HID0_ICE
+    andc    r3, r3, r4
+    sync
+    mtspr   HID0, r3
+/*
+ * invalidate caches
+ */
+    ori     r3, r3, (HID0_ICE | HID0_ICFI | HID0_DCI | HID0_DCE)
+    or      r4, r4, r3
+    isync
+    mtspr   HID0, r4
+    andc    r4, r4, r3
+    isync
+    mtspr   HID0, r4
+    isync
+/*
+ * icache_enable
+ */
+    mfspr   r3, HID0
+    ori     r3, r3, (HID0_ICE | HID0_ICFI)
+    sync
+    mtspr   HID0, r3
+
+
+/*
+ * setup memory controller
+ */
+    lis     r1, MPC106_REG_ADDR@h
+    ori     r1, r1, MPC106_REG_ADDR@l
+    lis     r2, MPC106_REG_DATA@h
+    ori     r2, r2, MPC106_REG_DATA@l
+
+    /* Configure PICR1 */
+    lis     r3, MPC106_REG@h
+    ori     r3, r3, PCI_PICR1
+    stwbrx  r3, 0, r1
+    addis   r3, r0, 0xFF14
+    ori     r3, r3, 0x1CC8
+    eieio
+    stwbrx  r3, 0, r2
+
+    /* Configure PICR2 */
+    lis     r3, MPC106_REG@h
+    ori     r3, r3, PCI_PICR2
+    stwbrx  r3, 0, r1
+    addis   r3, r0, 0x0000
+    ori     r3, r3, 0x0000
+    eieio
+    stwbrx  r3, 0, r2
+
+    /* Configure EUMBAR */
+    lis     r3, MPC106_REG@h
+    ori     r3, r3, 0x0078      /* offest of EUMBAR in PCI config space */
+    stwbrx  r3, 0, r1
+    lis     r3, MPC107_EUMB_ADDR@h
+    eieio
+    stwbrx  r3, 0, r2
+
+    /* Configure Address Map B Option Reg */
+    lis     r3, MPC106_REG@h
+    ori     r3, r3, 0x00e0      /* offest of AMBOR in PCI config space */
+    stwbrx  r3, 0, r1
+    lis     r3, 0
+    eieio
+    stwbrx  r3, 0, r2
+
+    /* Configure I2C Controller */
+    lis     r14, MPC107_I2C_ADDR@h  /* base of I2C controller */
+    ori     r14, r14, MPC107_I2C_ADDR@l
+    lis     r3, 0x2b10          /* I2C clock = 100MHz/1024 */
+    stw     r3, 4(r14)
+    li      r3, 0               /* clear arbitration */
+    eieio
+    stw     r3, 12(r14)
+
+    /* Configure MCCR1 */
+    lis     r3, MPC106_REG@h
+    ori     r3, r3, MPC106_MCCR1
+    stwbrx  r3, 0, r1
+    addis   r3, r0, 0x0660      /* don't set MEMGO now ! */
+    ori     r3, r3, 0x0000
+    eieio
+    stwbrx  r3, 0, r2
+
+    /* Configure MCCR2 */
+    lis     r3, MPC106_REG@h
+    ori     r3, r3, MPC106_MCCR2
+    stwbrx  r3, 0, r1
+    addis   r3, r0, 0x0400
+    ori     r3, r3, 0x1800
+    eieio
+    stwbrx  r3, 0, r2
+
+
+    /* Configure MCCR3 */
+    lis     r3, MPC106_REG@h
+    ori     r3, r3, MPC106_MCCR3
+    stwbrx  r3, 0, r1
+    addis   r3, r0, 0x0230
+    ori     r3, r3, 0x0000
+    eieio
+    stwbrx  r3, 0, r2
+
+    /* Configure MCCR4 */
+    lis     r3, MPC106_REG@h
+    ori     r3, r3, MPC106_MCCR4
+    stwbrx  r3, 0, r1
+    addis   r3, r0, 0x2532
+    ori     r3, r3, 0x2220
+    eieio
+    stwbrx  r3, 0, r2
+
+/*
+ * configure memory interface (MICRs)
+ */
+    addis   r3, r0, 0x8000      /* ADDR_80 */
+    ori     r3, r3, 0x0080      /* SMEMADD1 */
+    stwbrx  r3, 0, r1
+    addis   r3, r0, 0xFFFF
+    ori     r3, r3, 0x4000
+    eieio
+    stwbrx  r3, 0, r2
+
+    addis   r3, r0, 0x8000      /* ADDR_84 */
+    ori     r3, r3, 0x0084      /* SMEMADD2 */
+    stwbrx  r3, 0, r1
+    addis   r3, r0, 0xFFFF
+    ori     r3, r3, 0xFFFF
+    eieio
+    stwbrx  r3, 0, r2
+
+    addis   r3, r0, 0x8000      /* ADDR_88 */
+    ori     r3, r3, 0x0088      /* EXTSMEM1 */
+    stwbrx  r3, 0, r1
+    addis   r3, r0, 0x0303
+    ori     r3, r3, 0x0000
+    eieio
+    stwbrx  r3, 0, r2
+
+    addis   r3, r0, 0x8000      /* ADDR_8C */
+    ori     r3, r3, 0x008c      /* EXTSMEM2 */
+    stwbrx  r3, 0, r1
+    addis   r3, r0, 0x0303
+    ori     r3, r3, 0x0303
+    eieio
+    stwbrx  r3, 0, r2
+
+    addis   r3, r0, 0x8000      /* ADDR_90 */
+    ori     r3, r3, 0x0090      /* EMEMADD1 */
+    stwbrx  r3, 0, r1
+    addis   r3, r0, 0xFFFF
+    ori     r3, r3, 0x7F3F
+    eieio
+    stwbrx  r3, 0, r2
+
+    addis   r3, r0, 0x8000      /* ADDR_94 */
+    ori     r3, r3, 0x0094      /* EMEMADD2 */
+    stwbrx  r3, 0, r1
+    addis   r3, r0, 0xFFFF
+    ori     r3, r3, 0xFFFF
+    eieio
+    stwbrx  r3, 0, r2
+
+    addis   r3, r0, 0x8000      /* ADDR_98 */
+    ori     r3, r3, 0x0098      /* EXTEMEM1 */
+    stwbrx  r3, 0, r1
+    addis   r3, r0, 0x0303
+    ori     r3, r3, 0x0000
+    eieio
+    stwbrx  r3, 0, r2
+
+    addis   r3, r0, 0x8000      /* ADDR_9C */
+    ori     r3, r3, 0x009c      /* EXTEMEM2 */
+    stwbrx  r3, 0, r1
+    addis   r3, r0, 0x0303
+    ori     r3, r3, 0x0303
+    eieio
+    stwbrx  r3, 0, r2
+
+    addis   r3, r0, 0x8000      /* ADDR_A0 */
+    ori     r3, r3, 0x00a0      /* MEMBNKEN */
+    stwbrx  r3, 0, r1
+    addis   r3, r0, 0x0000
+    ori     r3, r3, 0x0003
+    eieio
+    stwbrx  r3, 0, r2
+
+/*
+ * must wait at least 100us after HRESET to issue a MEMGO
+ */
+    lis     r0, 1
+    mtctr   r0
+memStartWait:
+    bdnz    memStartWait
+
+/*
+ * enable RAM Operations through MCCR1 (MEMGO)
+ */
+    lis     r3, 0x8000
+    ori     r3, r3, 0x00f0
+    stwbrx  r3, r0, r1
+    sync
+    lwbrx   r3, 0, r2
+    lis     r0, 0x0008
+    or      r3, r0, r3
+    stwbrx  r3, 0, r2
+    sync
+
+/*
+ * set LEDs first time
+ */
+    li      r3, 0x1
+    lis     r30, CFG_USR_LED_BASE@h
+    stb     r3, 2(r30)
+    sync
+
+/*
+ * init COM1 for polled output
+ */
+    lis     r8, CFG_NS16550_COM1@h  /* COM1 base address*/
+    ori     r8, r8, CFG_NS16550_COM1@l
+    li      r9, 0x00
+    stb     r9, 1(r8)           /* int disabled */
+    eieio
+    li      r9, 0x00
+    stb     r9, 4(r8)           /* modem ctrl */
+    eieio
+    li      r9, 0x80
+    stb     r9, 3(r8)           /* link ctrl */
+    eieio
+    li      r9, (CFG_NS16550_CLK / 16 / CONFIG_BAUDRATE)
+    stb     r9, 0(r8)           /* baud rate (LSB)*/
+    eieio
+    li      r9, ((CFG_NS16550_CLK / 16 / CONFIG_BAUDRATE) >> 8)
+    stb     r9, 1(r8)           /* baud rate (MSB) */
+    eieio
+    li      r9, 0x07
+    stb     r9, 3(r8)           /* 8 data bits, 2 stop bit, no parity */
+    eieio
+    li      r9, 0x0b
+    stb     r9, 4(r8)           /* enable the receiver and transmitter (modem ctrl) */
+    eieio
+waitEmpty:
+    lbz     r9, 5(r8)           /* transmit empty */
+    andi.   r9, r9, 0x40
+    beq     waitEmpty
+    li      r9, 0x47
+    stb     r9, 3(r8)           /* send break, 8 data bits, 2 stop bit, no parity */
+    eieio
+
+    lis     r0, 0x0001
+    mtctr   r0
+waitCOM1:
+    lwz     r0, 5(r8)           /* load from port for delay */
+    bdnz    waitCOM1
+
+waitEmpty1:
+    lbz     r9, 5(r8)           /* transmit empty */
+    andi.   r9, r9, 0x40
+    beq     waitEmpty1
+    li      r9, 0x07
+    stb     r9, 3(r8)           /* 8 data bits, 2 stop bit, no parity */
+    eieio
+
+/*
+ * intro message from message block
+ */
+    addi    r3, r29, (MnewLine-MessageBlock)
+    bl      Printf
+    addi    r3, r29, (MinitLogo-MessageBlock)
+    bl      Printf
+
+/*
+ * memory cofiguration using SPD information stored on the SODIMMs
+ */
+    addi    r3, r29, (Mspd01-MessageBlock)
+    bl      Printf
+
+    li      r17, 0
+
+    li      r3, 0x0002          /* get RAM type from spd for bank0/1 */
+    bl      spdRead
+
+    cmpi    0, 0, r3, -1        /* error ? */
+    bne     noSpdError
+
+    addi    r3, r29, (Mfail-MessageBlock)
+    bl      Printf
+
+    li      r6, 0xe             /* error codes in r6 and r7  */
+    li      r7, 0x0
+    b       toggleError         /* fail - loop forever */
+
+noSpdError:
+    mr      r15, r3             /* save r3 */
+
+    addi    r3, r29, (Mok-MessageBlock)
+    bl      Printf
+
+    cmpli   0, 0, r15, 0x0004   /* SDRAM ? */
+    beq     isSDRAM
+
+    addi    r3, r29, (MramTyp-MessageBlock)
+    bl      Printf
+
+    li      r6, 0xd             /* error codes in r6 and r7  */
+    li      r7, 0x0
+    b       toggleError         /* fail - loop forever */
+
+isSDRAM:
+    li      r3, 0x0012          /* get supported CAS latencies from byte 18 */
+    bl      spdRead
+    mr      r15, r3
+    li      r3, 0x09
+    andi.   r0, r15, 0x04
+    bne     maxCLis3
+    li      r3, 0x17
+maxCLis3:
+    andi.   r0, r15, 0x02
+    bne     CL2
+
+    addi    r3, r29, (MramTyp-MessageBlock)
+    bl      Printf
+
+    li      r6, 0xc             /* error codes in r6 and r7  */
+    li      r7, 0x0
+    b       toggleError         /* fail - loop forever */
+CL2:
+    bl      spdRead
+    cmpli   0, 0, r3, 0xa1      /* cycle time must be 10ns max. */
+    blt     speedOk
+
+    addi    r3, r29, (MramTyp-MessageBlock)
+    bl      Printf
+
+    li      r6, 0xb             /* error codes in r6 and r7  */
+    li      r7, 0x0
+    b       toggleError         /* fail - loop forever */
+speedOk:
+    lis     r20, 0x06e8         /* preset MCR1 value */
+
+    li      r3, 0x0011          /* get number of internal banks from spd for bank0/1 */
+    bl      spdRead
+
+    cmpli   0, 0, r3, 0x02
+    beq     SD_2B
+    cmpli   0, 0, r3, 0x04
+    beq     SD_4B
+memConfErr:
+    addi    r3, r29, (MramConfErr-MessageBlock)
+    bl      Printf
+
+    li      r6, 0xa             /* error codes in r6 and r7  */
+    li      r7, 0x0
+    b       toggleError         /* fail - loop forever */
+
+SD_2B:
+    li      r3, 0x0003          /* get number of row bits from spd for bank0/1 */
+    bl      spdRead
+    cmpli   0, 0, r3, 0x0b
+    beq     row11x2
+    cmpli   0, 0, r3, 0x0c
+    beq     row12x2or13x2
+    cmpli   0, 0, r3, 0x0d
+    beq     row12x2or13x2
+    b       memConfErr
+SD_4B:
+    li      r3, 0x0003          /* get number of row bits from spd for bank0/1 */
+    bl      spdRead
+    cmpli   0, 0, r3, 0x0b
+    beq     row11x4or12x4
+    cmpli   0, 0, r3, 0x0c
+    beq     row11x4or12x4
+    cmpli   0, 0, r3, 0x0d
+    beq     row13x4
+    b       memConfErr
+row12x2or13x2:
+    ori     r20, r20, 0x05
+    b       row11x4or12x4
+row13x4:
+    ori     r20, r20, 0x0a
+    b       row11x4or12x4
+row11x2:
+    ori     r20, r20, 0x0f
+row11x4or12x4:
+    /* get the size of bank 0-1 */
+
+    li      r3, 0x001f          /* get bank size from spd for bank0/1 */
+    bl      spdRead
+
+    rlwinm  r16, r3, 2, 24, 29  /* calculate size in MByte (128 MB max.) */
+
+    li      r3, 0x0005          /* get number of banks from spd for bank0/1 */
+    bl      spdRead
+
+    cmpi    0, 0, r3, 2         /* 2 banks ? */
+    bne     SDRAMnobank1
+
+    mr      r17, r16
+
+SDRAMnobank1:
+    li      r3, 0x000c          /* get refresh from spd for bank0/1 */
+    bl      spdRead
+    andi.   r3, r3, 0x007f      /* mask selfrefresh bit */
+    li      r4, 0x1800          /* refesh cycle 1536 clocks left shifted 2 */
+    cmpli   0, 0, r3, 0x0000    /* 15.6 us ? */
+    beq     writeRefresh
+
+    li      r4, 0x0c00          /* refesh cycle 768 clocks left shifted 2 */
+    cmpli   0, 0, r3, 0x0002    /* 7.8 us ? */
+    beq     writeRefresh
+
+    li      r4, 0x3000          /* refesh cycle 3072 clocks left shifted 2 */
+    cmpli   0, 0, r3, 0x0003    /* 31.3 us ? */
+    beq     writeRefresh
+
+    li      r4, 0x6000          /* refesh cycle 6144 clocks left shifted 2 */
+    cmpli   0, 0, r3, 0x0004    /* 62.5 us ? */
+    beq     writeRefresh
+
+    li      r4, 0
+    ori     r4, r4, 0xc000      /* refesh cycle 8224 clocks left shifted 2 */
+    cmpli   0, 0, r3, 0x0005    /* 125 us ? */
+    beq     writeRefresh
+
+    b       memConfErr
+
+writeRefresh:
+    lis     r21, 0x0400         /* preset MCCR2 value */
+    or      r21, r21, r4
+
+    /* Overwrite MCCR1 */
+    lis     r3, MPC106_REG@h
+    ori     r3, r3, MPC106_MCCR1
+    stwbrx  r3, 0, r1
+    eieio
+    stwbrx  r20, 0, r2
+
+    /* Overwrite MCCR2 */
+    lis     r3, MPC106_REG@h
+    ori     r3, r3, MPC106_MCCR2
+    stwbrx  r3, 0, r1
+    eieio
+    stwbrx  r21, 0, r2
+
+    /* set the memory boundary registers for bank 0-3 */
+    li      r20, 0
+    lis     r23, 0x0303
+    lis     r24, 0x0303
+    subi    r21, r16, 1         /* calculate end address bank0 */
+    li      r22, 1
+
+    cmpi    0, 0, r17, 0        /* bank1 present ? */
+    beq     nobank1
+
+    andi.   r3, r16, 0x00ff     /* calculate start address of bank1 */
+    andi.   r4, r16, 0x0300
+    rlwinm  r3, r3, 8, 16, 23
+    or      r20, r20, r3
+    or      r23, r23, r4
+
+    add     r16, r16, r17       /* add to total memory size */
+
+    subi    r3, r16, 1          /* calculate end address of bank1 */
+    andi.   r4, r3, 0x0300
+    andi.   r3, r3, 0x00ff
+    rlwinm  r3, r3, 8, 16, 23
+    or      r21, r21, r3
+    or      r24, r24, r4
+
+    ori     r22, r22, 2         /* enable bank1 */
+    b       bankOk
+nobank1:
+    ori     r23, r23, 0x0300    /* set bank1 start to unused area */
+    ori     r24, r24, 0x0300    /* set bank1 end to unused area */
+bankOk:
+    addi    r3, r29, (Mactivate-MessageBlock)
+    bl      Printf
+    mr      r3, r16
+    bl      OutDec
+    addi    r3, r29, (Mact0123e-MessageBlock)
+    bl      Printf
+
+/*
+ * overwrite MSAR1, MEAR1, EMSAR1, and EMEAR1
+ */
+    addis   r3, r0, 0x8000      /* ADDR_80 */
+    ori     r3, r3, 0x0080      /* MSAR1 */
+    stwbrx  r3, 0, r1
+    eieio
+    stwbrx  r20, 0, r2
+
+    addis   r3, r0, 0x8000      /* ADDR_88 */
+    ori     r3, r3, 0x0088      /* EMSAR1 */
+    stwbrx  r3, 0, r1
+    eieio
+    stwbrx  r23, 0, r2
+
+    addis   r3, r0, 0x8000      /* ADDR_90 */
+    ori     r3, r3, 0x0090      /* MEAR1 */
+    stwbrx  r3, 0, r1
+    eieio
+    stwbrx  r21, 0, r2
+
+    addis   r3, r0, 0x8000      /* ADDR_98 */
+    ori     r3, r3, 0x0098      /* EMEAR1 */
+    stwbrx  r3, 0, r1
+    eieio
+    stwbrx  r24, 0, r2
+
+    addis   r3, r0, 0x8000      /* ADDR_A0 */
+    ori     r3, r3, 0x00a0      /* MBER */
+    stwbrx  r3, 0, r1
+    eieio
+    stwbrx  r22, 0, r2
+
+/*
+ * delay to let SDRAM go through several initialization/refresh cycles
+ */
+    lis     r3, 3
+    mtctr   r3
+memStartWait_1:
+    bdnz    memStartWait_1
+    eieio
+
+/*
+ * set LEDs end
+ */
+    li      r3, 0xf
+    lis     r30, CFG_USR_LED_BASE@h
+    stb     r3, 2(r30)
+    sync
+
+    mtlr    r13
+    blr                         /* EXIT board_asm_init ... */
+
+/*----------------------------------------------------------------------------*/
+/*
+ * print a message to COM1 in polling mode (r10=COM1 port, r3=(char*)string)
+ */
+
+Printf:
+    lis     r10, CFG_NS16550_COM1@h /* COM1 base address*/
+    ori     r10, r10, CFG_NS16550_COM1@l
+WaitChr:
+    lbz     r0, 5(r10)          /* read link status */
+    eieio
+    andi.   r0, r0, 0x40        /* mask transmitter empty bit */
+    beq     cr0, WaitChr        /* wait till empty */
+    lbzx    r0, r0, r3          /* get char */
+    stb     r0, 0(r10)          /* write to transmit reg */
+    eieio
+    addi    r3, r3, 1           /* next char */
+    lbzx    r0, r0, r3          /* get char */
+    cmpwi   cr1, r0, 0          /* end of string ? */
+    bne     cr1, WaitChr
+    blr
+
+/*
+ * print a char to COM1 in polling mode (r10=COM1 port, r3=char)
+ */
+OutChr:
+    lis     r10, CFG_NS16550_COM1@h /* COM1 base address*/
+    ori     r10, r10, CFG_NS16550_COM1@l
+OutChr1:
+    lbz     r0, 5(r10)          /* read link status */
+    eieio
+    andi.   r0, r0, 0x40        /* mask transmitter empty bit */
+    beq     cr0, OutChr1        /* wait till empty */
+    stb     r3, 0(r10)          /* write to transmit reg */
+    eieio
+    blr
+
+/*
+ * print 8/4/2 digits hex value to COM1 in polling mode (r10=COM1 port, r3=val)
+ */
+OutHex2:
+    li      r9, 4               /* shift reg for 2 digits */
+    b       OHstart
+OutHex4:
+    li      r9, 12              /* shift reg for 4 digits */
+    b       OHstart
+OutHex:
+    li      r9, 28              /* shift reg for 8 digits */
+OHstart:
+    lis     r10, CFG_NS16550_COM1@h /* COM1 base address*/
+    ori     r10, r10, CFG_NS16550_COM1@l
+OutDig:
+    lbz     r0, 0(r29)          /* slow down dummy read */
+    lbz     r0, 5(r10)          /* read link status */
+    eieio
+    andi.   r0, r0, 0x40        /* mask transmitter empty bit */
+    beq     cr0, OutDig
+    sraw    r0, r3, r9
+    clrlwi  r0, r0, 28
+    cmpwi   cr1, r0, 9
+    ble     cr1, digIsNum
+    addic   r0, r0, 55
+    b       nextDig
+digIsNum:
+    addic   r0, r0, 48
+nextDig:
+    stb     r0, 0(r10)          /* write to transmit reg */
+    eieio
+    addic.  r9, r9, -4
+    bge     OutDig
+    blr
+
+/*
+ * print 3 digits hdec value to COM1 in polling mode
+ * (r10=COM1 port, r3=val, r7=x00, r8=x0, r9=x, r0, r6=scratch)
+ */
+OutDec:
+    li      r6, 10
+    divwu   r0, r3, r6          /* r0 = r3 / 10, r9 = r3 mod 10 */
+    mullw   r10, r0, r6
+    subf    r9, r10, r3
+    mr      r3, r0
+    divwu   r0, r3, r6          /* r0 = r3 / 10, r8 = r3 mod 10 */
+    mullw   r10, r0, r6
+    subf    r8, r10, r3
+    mr      r3, r0
+    divwu   r0, r3, r6          /* r0 = r3 / 10, r7 = r3 mod 10 */
+    mullw   r10, r0, r6
+    subf    r7, r10, r3
+    lis     r10, CFG_NS16550_COM1@h /* COM1 base address*/
+    ori     r10, r10, CFG_NS16550_COM1@l
+    or.     r7, r7, r7
+    bne     noblank1
+    li      r3, 0x20
+    b       OutDec4
+noblank1:
+    addi    r3, r7, 48          /* convert to ASCII */
+OutDec4:
+    lbz     r0, 0(r29)          /* slow down dummy read */
+    lbz     r0, 5(r10)          /* read link status */
+    eieio
+    andi.   r0, r0, 0x40        /* mask transmitter empty bit */
+    beq     cr0, OutDec4
+    stb     r3, 0(r10)          /* x00 to transmit */
+    eieio
+    or.     r7, r7, r8
+    beq     OutDec5
+    addi    r3, r8, 48          /* convert to ASCII */
+OutDec5:
+    lbz     r0, 0(r29)          /* slow down dummy read */
+    lbz     r0, 5(r10)          /* read link status */
+    eieio
+    andi.   r0, r0, 0x40        /* mask transmitter empty bit */
+    beq     cr0, OutDec5
+    stb     r3, 0(r10)          /* x0  to transmit */
+    eieio
+    addi    r3, r9, 48          /* convert to ASCII */
+OutDec6:
+    lbz     r0, 0(r29)          /* slow down dummy read */
+    lbz     r0, 5(r10)          /* read link status */
+    eieio
+    andi.   r0, r0, 0x40        /* mask transmitter empty bit */
+    beq     cr0, OutDec6
+    stb     r3, 0(r10)          /* x   to transmit */
+    eieio
+    blr
+
+/*
+ * hang endless loop
+ */
+toggleError:                    /* fail type in r6, r7=0xff, toggle LEDs */
+    stb     r7, 2(r30)          /* r7 to LED */
+    li      r0, 0
+    lis     r9, 127
+    ori     r9, r9, 65535
+toggleError1:
+    addic   r0, r0, 1
+    cmpw    cr1, r0, r9
+    ble     cr1, toggleError1
+    stb     r6, 2(r30)          /* r6 to LED */
+    li      r0, 0
+    lis     r9, 127
+    ori     r9, r9, 65535
+toggleError2:
+    addic   r0, r0, 1
+    cmpw    cr1, r0, r9
+    ble     cr1, toggleError2
+    b       toggleError
+
+/*
+ * routines to read from ram spd
+ */
+spdWaitIdle:
+    lis     r0, 0x1             /* timeout for about 100us */
+    mtctr   r0
+iSpd:
+    lbz     r10, 12(r14)
+    andi.   r10, r10, 0x20      /* mask and test MBB */
+    beq     idle
+    bdnz    iSpd
+    orc.    r10, r0, r0         /* return -1 to caller */
+idle:
+    bclr    20, 0               /* return to caller */
+
+waitSpd:
+    lis     r0, 0x10            /* timeout for about 1.5ms */
+    mtctr   r0
+wSpd:
+    lbz     r10, 12(r14)
+    andi.   r10, r10, 0x82
+    cmpli   0, 0, r10, 0x82     /* test MCF and MIF set */
+    beq     wend
+    bdnz    wSpd
+    orc.    r10, r0, r0         /* return -1 to caller */
+    bclr    20, 0               /* return to caller */
+
+wend:
+    li      r10, 0
+    stb     r10, 12(r14)        /* clear status */
+    bclr    20, 0               /* return to caller */
+
+/*
+ * spdread
+ * in:  r3 adr to read
+ * out: r3 val or -1 for error
+ * uses r10, assumes that r14 points to I2C controller
+ */
+spdRead:
+    mfspr   r25, 8              /* save link register */
+
+    bl      spdWaitIdle
+    bne     spdErr
+
+    li      r10, 0x80           /* start with MEN */
+    stb     r10, 8(r14)
+    eieio
+
+    li      r10, 0xb0           /* start as master */
+    stb     r10, 8(r14)
+    eieio
+
+    li      r10, 0xa0           /* write device 0xA0 */
+    stb     r10, 16(r14)
+    eieio
+    bl      waitSpd
+    bne     spdErr
+
+    lbz     r10, 12(r14)        /* test ACK */
+    andi.   r10, r10, 0x01
+    bne     gotNoAck
+
+    stb     r3, 16(r14)         /* data address */
+    eieio
+    bl      waitSpd
+    bne     spdErr
+
+
+    li      r10, 0xb4           /* switch to read - restart */
+    stb     r10, 8(r14)
+    eieio
+
+    li      r10, 0xa1           /* read device 0xA0 */
+    stb     r10, 16(r14)
+    eieio
+    bl      waitSpd
+    bne     spdErr
+
+    li      r10, 0xa8           /* no ACK */
+    stb     r10, 8(r14)
+    eieio
+
+    lbz     r10, 16(r14)        /* trigger read next byte */
+    eieio
+    bl      waitSpd
+    bne     spdErr
+
+    li      r10, 0x88           /* generate STOP condition */
+    stb     r10, 8(r14)
+    eieio
+
+    lbz     r3, 16(r14)         /* return read byte */
+
+    mtspr   8, r25              /* restore link register */
+    blr
+
+gotNoAck:
+    li      r10, 0x80           /* generate STOP condition */
+    stb     r10, 8(r14)
+    eieio
+spdErr:
+    orc     r3, r0, r0          /* return -1 */
+    mtspr   8, r25              /* restore link register */
+    blr
+
+get_lnk_reg:
+    mflr    r3                  /* return link reg */
+    blr
+
+MessageBlock:
+
+MinitLogo:
+    .ascii  "\015\012*** ELTEC Elektronik, Mainz ***\015\012"
+    .ascii  "\015\012Initialising RAM\015\012\000"
+Mspd01:
+    .ascii  "       Reading SPD of SODIMM ...... \000"
+MramTyp:
+    .ascii  "\015\012\SDRAM with CL=2 at 100 MHz required!\015\012\000"
+MramConfErr:
+    .ascii  "\015\012\Unsupported SODIMM Configuration!\015\012\000"
+Mactivate:
+    .ascii  "       Activating \000"
+Mact0123e:
+    .ascii  " MByte.\015\012\000"
+Mok:
+    .ascii  "OK \015\012\000"
+Mfail:
+    .ascii  "FAILED \015\012\000"
+MnewLine:
+    .ascii  "\015\012\000"
+    .align 4