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Diffstat (limited to 'arch/m68knommu/platform/5307/head.S')
| -rw-r--r-- | arch/m68knommu/platform/5307/head.S | 253 |
1 files changed, 253 insertions, 0 deletions
diff --git a/arch/m68knommu/platform/5307/head.S b/arch/m68knommu/platform/5307/head.S new file mode 100644 index 000000000000..c7d7a395c4cc --- /dev/null +++ b/arch/m68knommu/platform/5307/head.S @@ -0,0 +1,253 @@ +/*****************************************************************************/ + +/* + * head.S -- common startup code for ColdFire CPUs. + * + * (C) Copyright 1999-2004, Greg Ungerer (gerg@snapgear.com). + */ + +/*****************************************************************************/ + +#include <linux/config.h> +#include <linux/sys.h> +#include <linux/linkage.h> +#include <asm/asm-offsets.h> +#include <asm/coldfire.h> +#include <asm/mcfcache.h> +#include <asm/mcfsim.h> + +/*****************************************************************************/ + +/* + * Define fixed memory sizes. Configuration of a fixed memory size + * overrides everything else. If the user defined a size we just + * blindly use it (they know what they are doing right :-) + */ +#if defined(CONFIG_RAM32MB) +#define MEM_SIZE 0x02000000 /* memory size 32Mb */ +#elif defined(CONFIG_RAM16MB) +#define MEM_SIZE 0x01000000 /* memory size 16Mb */ +#elif defined(CONFIG_RAM8MB) +#define MEM_SIZE 0x00800000 /* memory size 8Mb */ +#elif defined(CONFIG_RAM4MB) +#define MEM_SIZE 0x00400000 /* memory size 4Mb */ +#elif defined(CONFIG_RAM1MB) +#define MEM_SIZE 0x00100000 /* memory size 1Mb */ +#endif + +/* + * Memory size exceptions for special cases. Some boards may be set + * for auto memory sizing, but we can't do it that way for some reason. + * For example the 5206eLITE board has static RAM, and auto-detecting + * the SDRAM will do you no good at all. + */ +#ifdef CONFIG_RAMAUTO +#if defined(CONFIG_M5206eLITE) +#define MEM_SIZE 0x00100000 /* 1MiB default memory */ +#endif +#endif /* CONFIG_RAMAUTO */ + +/* + * If we don't have a fixed memory size now, then lets build in code + * to auto detect the DRAM size. Obviously this is the prefered + * method, and should work for most boards (it won't work for those + * that do not have their RAM starting at address 0). + */ +#if defined(MEM_SIZE) +.macro GET_MEM_SIZE + movel #MEM_SIZE,%d0 /* hard coded memory size */ +.endm + +#elif defined(CONFIG_M5206) || defined(CONFIG_M5206e) || \ + defined(CONFIG_M5249) || defined(CONFIG_M527x) || \ + defined(CONFIG_M528x) || defined(CONFIG_M5307) || \ + defined(CONFIG_M5407) +/* + * Not all these devices have exactly the same DRAM controller, + * but the DCMR register is virtually identical - give or take + * a couple of bits. The only exception is the 5272 devices, their + * DRAM controller is quite different. + */ +.macro GET_MEM_SIZE + movel MCF_MBAR+MCFSIM_DMR0,%d0 /* get mask for 1st bank */ + btst #0,%d0 /* check if region enabled */ + beq 1f + andl #0xfffc0000,%d0 + beq 1f + addl #0x00040000,%d0 /* convert mask to size */ +1: + movel MCF_MBAR+MCFSIM_DMR1,%d1 /* get mask for 2nd bank */ + btst #0,%d1 /* check if region enabled */ + beq 2f + andl #0xfffc0000, %d1 + beq 2f + addl #0x00040000,%d1 + addl %d1,%d0 /* total mem size in d0 */ +2: +.endm + +#elif defined(CONFIG_M5272) +.macro GET_MEM_SIZE + movel MCF_MBAR+MCFSIM_CSOR7,%d0 /* get SDRAM address mask */ + andil #0xfffff000,%d0 /* mask out chip select options */ + negl %d0 /* negate bits */ +.endm + +#else +#error "ERROR: I don't know how to determine your boards memory size?" +#endif + + +/* + * Most ColdFire boards have their DRAM starting at address 0. + * Notable exception is the 5206eLITE board. + */ +#if defined(CONFIG_M5206eLITE) +#define MEM_BASE 0x30000000 +#endif + +#ifndef MEM_BASE +#define MEM_BASE 0x00000000 /* memory base at address 0 */ +#endif + +/* + * The default location for the vectors is at the base of RAM. + * Some boards might like to use internal SRAM or something like + * that. If no board specific header defines an alternative then + * use the base of RAM. + */ +#ifndef VBR_BASE +#define VBR_BASE MEM_BASE /* vector address */ +#endif + +/*****************************************************************************/ + +/* + * Boards and platforms can do specific early hardware setup if + * they need to. Most don't need this, define away if not required. + */ +#ifndef PLATFORM_SETUP +#define PLATFORM_SETUP +#endif + +/*****************************************************************************/ + +.global _start +.global _rambase +.global _ramvec +.global _ramstart +.global _ramend + +/*****************************************************************************/ + +.data + +/* + * During startup we store away the RAM setup. These are not in the + * bss, since their values are determined and written before the bss + * has been cleared. + */ +_rambase: +.long 0 +_ramvec: +.long 0 +_ramstart: +.long 0 +_ramend: +.long 0 + +/*****************************************************************************/ + +.text + +/* + * This is the codes first entry point. This is where it all + * begins... + */ + +_start: + nop /* filler */ + movew #0x2700, %sr /* no interrupts */ + + /* + * Do any platform or board specific setup now. Most boards + * don't need anything. Those exceptions are define this in + * their board specific includes. + */ + PLATFORM_SETUP + + /* + * Create basic memory configuration. Set VBR accordingly, + * and size memory. + */ + movel #VBR_BASE,%a7 + movec %a7,%VBR /* set vectors addr */ + movel %a7,_ramvec + + movel #MEM_BASE,%a7 /* mark the base of RAM */ + movel %a7,_rambase + + GET_MEM_SIZE /* macro code determines size */ + movel %d0,_ramend /* set end ram addr */ + + /* + * Now that we know what the memory is, lets enable cache + * and get things moving. This is Coldfire CPU specific. + */ + CACHE_ENABLE /* enable CPU cache */ + + +#ifdef CONFIG_ROMFS_FS + /* + * Move ROM filesystem above bss :-) + */ + lea _sbss,%a0 /* get start of bss */ + lea _ebss,%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),%d0 /* copy dword */ + movel %d0,-(%a1) + cmpl %a0,%a2 /* check if at end */ + bne _copy_romfs + +#else /* CONFIG_ROMFS_FS */ + lea _ebss,%a1 + movel %a1,_ramstart +#endif /* CONFIG_ROMFS_FS */ + + + /* + * Zero out the bss region. + */ + lea _sbss,%a0 /* get start of bss */ + lea _ebss,%a1 /* get end of bss */ + clrl %d0 /* set value */ +_clear_bss: + movel %d0,(%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 + + /* + * Assember start up done, start code proper. + */ + jsr start_kernel /* start Linux kernel */ + +_exit: + jmp _exit /* should never get here */ + +/*****************************************************************************/ |