240 lines
8.2 KiB
ArmAsm
240 lines
8.2 KiB
ArmAsm
/*
|
|
* head.S - Common startup code for 68000 core based CPU's
|
|
*
|
|
* 2012.10.21, Luis Alves <ljalvs@gmail.com>, Single head.S file for all
|
|
* 68000 core based CPU's. Based on the sources from:
|
|
* Coldfire by Greg Ungerer <gerg@snapgear.com>
|
|
* 68328 by D. Jeff Dionne <jeff@ryeham.ee.ryerson.ca>,
|
|
* Kenneth Albanowski <kjahds@kjahds.com>,
|
|
* The Silver Hammer Group, Ltd.
|
|
*
|
|
*/
|
|
|
|
#include <linux/linkage.h>
|
|
#include <linux/init.h>
|
|
#include <asm/asm-offsets.h>
|
|
#include <asm/thread_info.h>
|
|
|
|
|
|
/*****************************************************************************
|
|
* UCSIMM and UCDIMM use CONFIG_MEMORY_RESERVE to reserve some RAM
|
|
*****************************************************************************/
|
|
#ifdef CONFIG_MEMORY_RESERVE
|
|
#define RAMEND (CONFIG_RAMBASE+CONFIG_RAMSIZE)-(CONFIG_MEMORY_RESERVE*0x100000)
|
|
#else
|
|
#define RAMEND (CONFIG_RAMBASE+CONFIG_RAMSIZE)
|
|
#endif
|
|
/*****************************************************************************/
|
|
|
|
.global _start
|
|
.global _rambase
|
|
.global _ramvec
|
|
.global _ramstart
|
|
.global _ramend
|
|
|
|
#if defined(CONFIG_PILOT) || defined(CONFIG_INIT_LCD)
|
|
.global bootlogo_bits
|
|
#endif
|
|
|
|
/* Defining DEBUG_HEAD_CODE, serial port in 68x328 is inited */
|
|
/* #define DEBUG_HEAD_CODE */
|
|
#undef DEBUG_HEAD_CODE
|
|
|
|
.data
|
|
|
|
/*****************************************************************************
|
|
* RAM setup pointers. Used by the kernel to determine RAM location and size.
|
|
*****************************************************************************/
|
|
|
|
_rambase:
|
|
.long 0
|
|
_ramvec:
|
|
.long 0
|
|
_ramstart:
|
|
.long 0
|
|
_ramend:
|
|
.long 0
|
|
|
|
__HEAD
|
|
|
|
/*****************************************************************************
|
|
* Entry point, where all begins!
|
|
*****************************************************************************/
|
|
|
|
_start:
|
|
|
|
/* Pilot need this specific signature at the start of ROM */
|
|
#ifdef CONFIG_PILOT
|
|
.byte 0x4e, 0xfa, 0x00, 0x0a /* bra opcode (jmp 10 bytes) */
|
|
.byte 'b', 'o', 'o', 't'
|
|
.word 10000
|
|
nop
|
|
moveq #0, %d0
|
|
movew %d0, 0xfffff618 /* Watchdog off */
|
|
movel #0x00011f07, 0xfffff114 /* CS A1 Mask */
|
|
#endif /* CONFIG_PILOT */
|
|
|
|
movew #0x2700, %sr /* disable all interrupts */
|
|
|
|
/*****************************************************************************
|
|
* Setup PLL and wait for it to settle (in 68x328 cpu's).
|
|
* Also, if enabled, init serial port.
|
|
*****************************************************************************/
|
|
#if defined(CONFIG_M68328) || \
|
|
defined(CONFIG_M68EZ328) || \
|
|
defined(CONFIG_M68VZ328)
|
|
|
|
/* Serial port setup. Should only be needed if debugging this startup code. */
|
|
#ifdef DEBUG_HEAD_CODE
|
|
movew #0x0800, 0xfffff906 /* Ignore CTS */
|
|
movew #0x010b, 0xfffff902 /* BAUD to 9600 */
|
|
movew #0xe100, 0xfffff900 /* enable */
|
|
#endif /* DEBUG_HEAD */
|
|
|
|
#ifdef CONFIG_PILOT
|
|
movew #0x2410, 0xfffff200 /* PLLCR */
|
|
#else
|
|
movew #0x2400, 0xfffff200 /* PLLCR */
|
|
#endif
|
|
movew #0x0123, 0xfffff202 /* PLLFSR */
|
|
moveq #0, %d0
|
|
movew #16384, %d0 /* PLL settle wait loop */
|
|
_pll_settle:
|
|
subw #1, %d0
|
|
bne _pll_settle
|
|
#endif /* CONFIG_M68x328 */
|
|
|
|
|
|
/*****************************************************************************
|
|
* If running kernel from ROM some specific initialization has to be done.
|
|
* (Assuming that everything is already init'ed when running from RAM)
|
|
*****************************************************************************/
|
|
#ifdef CONFIG_ROMKERNEL
|
|
|
|
/*****************************************************************************
|
|
* Init chip registers (uCsimm specific)
|
|
*****************************************************************************/
|
|
#ifdef CONFIG_UCSIMM
|
|
moveb #0x00, 0xfffffb0b /* Watchdog off */
|
|
moveb #0x10, 0xfffff000 /* SCR */
|
|
moveb #0x00, 0xfffff40b /* enable chip select */
|
|
moveb #0x00, 0xfffff423 /* enable /DWE */
|
|
moveb #0x08, 0xfffffd0d /* disable hardmap */
|
|
moveb #0x07, 0xfffffd0e /* level 7 interrupt clear */
|
|
movew #0x8600, 0xfffff100 /* FLASH at 0x10c00000 */
|
|
movew #0x018b, 0xfffff110 /* 2Meg, enable, 0ws */
|
|
movew #0x8f00, 0xfffffc00 /* DRAM configuration */
|
|
movew #0x9667, 0xfffffc02 /* DRAM control */
|
|
movew #0x0000, 0xfffff106 /* DRAM at 0x00000000 */
|
|
movew #0x068f, 0xfffff116 /* 8Meg, enable, 0ws */
|
|
moveb #0x40, 0xfffff300 /* IVR */
|
|
movel #0x007FFFFF, %d0 /* IMR */
|
|
movel %d0, 0xfffff304
|
|
moveb 0xfffff42b, %d0
|
|
andb #0xe0, %d0
|
|
moveb %d0, 0xfffff42b
|
|
#endif
|
|
|
|
/*****************************************************************************
|
|
* Init LCD controller.
|
|
* (Assuming that LCD controller is already init'ed when running from RAM)
|
|
*****************************************************************************/
|
|
#ifdef CONFIG_INIT_LCD
|
|
#ifdef CONFIG_PILOT
|
|
moveb #0, 0xfffffA27 /* LCKCON */
|
|
movel #_start, 0xfffffA00 /* LSSA */
|
|
moveb #0xa, 0xfffffA05 /* LVPW */
|
|
movew #0x9f, 0xFFFFFa08 /* LXMAX */
|
|
movew #0x9f, 0xFFFFFa0a /* LYMAX */
|
|
moveb #9, 0xfffffa29 /* LBAR */
|
|
moveb #0, 0xfffffa25 /* LPXCD */
|
|
moveb #0x04, 0xFFFFFa20 /* LPICF */
|
|
moveb #0x58, 0xfffffA27 /* LCKCON */
|
|
moveb #0x85, 0xfffff429 /* PFDATA */
|
|
moveb #0xd8, 0xfffffA27 /* LCKCON */
|
|
moveb #0xc5, 0xfffff429 /* PFDATA */
|
|
moveb #0xd5, 0xfffff429 /* PFDATA */
|
|
movel #bootlogo_bits, 0xFFFFFA00 /* LSSA */
|
|
moveb #10, 0xFFFFFA05 /* LVPW */
|
|
movew #160, 0xFFFFFA08 /* LXMAX */
|
|
movew #160, 0xFFFFFA0A /* LYMAX */
|
|
#else /* CONFIG_PILOT */
|
|
movel #bootlogo_bits, 0xfffffA00 /* LSSA */
|
|
moveb #0x28, 0xfffffA05 /* LVPW */
|
|
movew #0x280, 0xFFFFFa08 /* LXMAX */
|
|
movew #0x1df, 0xFFFFFa0a /* LYMAX */
|
|
moveb #0, 0xfffffa29 /* LBAR */
|
|
moveb #0, 0xfffffa25 /* LPXCD */
|
|
moveb #0x08, 0xFFFFFa20 /* LPICF */
|
|
moveb #0x01, 0xFFFFFA21 /* -ve pol */
|
|
moveb #0x81, 0xfffffA27 /* LCKCON */
|
|
movew #0xff00, 0xfffff412 /* LCD pins */
|
|
#endif /* CONFIG_PILOT */
|
|
#endif /* CONFIG_INIT_LCD */
|
|
|
|
/*****************************************************************************
|
|
* Kernel is running from FLASH/ROM (XIP)
|
|
* Copy init text & data to RAM
|
|
*****************************************************************************/
|
|
moveal #_etext, %a0
|
|
moveal #_sdata, %a1
|
|
moveal #__bss_start, %a2
|
|
_copy_initmem:
|
|
movel %a0@+, %a1@+
|
|
cmpal %a1, %a2
|
|
bhi _copy_initmem
|
|
#endif /* CONFIG_ROMKERNEL */
|
|
|
|
/*****************************************************************************
|
|
* Setup basic memory information for kernel
|
|
*****************************************************************************/
|
|
movel #CONFIG_VECTORBASE,_ramvec /* set vector base location */
|
|
movel #CONFIG_RAMBASE,_rambase /* set the base of RAM */
|
|
movel #RAMEND, _ramend /* set end ram addr */
|
|
lea __bss_stop,%a1
|
|
movel %a1,_ramstart
|
|
|
|
/*****************************************************************************
|
|
* If the kernel is in RAM, move romfs to right above bss and
|
|
* adjust _ramstart to where romfs ends.
|
|
*
|
|
* (Do this only if CONFIG_MTD_UCLINUX is true)
|
|
*****************************************************************************/
|
|
|
|
#if defined(CONFIG_ROMFS_FS) && defined(CONFIG_RAMKERNEL) && \
|
|
defined(CONFIG_MTD_UCLINUX)
|
|
lea __bss_start, %a0 /* get start of bss */
|
|
lea __bss_stop, %a1 /* set up destination */
|
|
movel %a0, %a2 /* copy of bss start */
|
|
|
|
movel 8(%a0), %d0 /* get size of ROMFS */
|
|
addql #8, %d0 /* allow for rounding */
|
|
andl #0xfffffffc, %d0 /* whole words */
|
|
|
|
addl %d0, %a0 /* copy from end */
|
|
addl %d0, %a1 /* copy from end */
|
|
movel %a1, _ramstart /* set start of ram */
|
|
_copy_romfs:
|
|
movel -(%a0), -(%a1) /* copy dword */
|
|
cmpl %a0, %a2 /* check if at end */
|
|
bne _copy_romfs
|
|
#endif /* CONFIG_ROMFS_FS && CONFIG_RAMKERNEL && CONFIG_MTD_UCLINUX */
|
|
|
|
/*****************************************************************************
|
|
* Clear bss region
|
|
*****************************************************************************/
|
|
lea __bss_start, %a0 /* get start of bss */
|
|
lea __bss_stop, %a1 /* get end of bss */
|
|
_clear_bss:
|
|
movel #0, (%a0)+ /* clear each word */
|
|
cmpl %a0, %a1 /* check if at end */
|
|
bne _clear_bss
|
|
|
|
/*****************************************************************************
|
|
* Load the current task pointer and stack.
|
|
*****************************************************************************/
|
|
lea init_thread_union,%a0
|
|
lea THREAD_SIZE(%a0),%sp
|
|
jsr start_kernel /* start Linux kernel */
|
|
_exit:
|
|
jmp _exit /* should never get here */
|