From: Add startup code specific to newly supported COBRA5272 board. --- 25-akpm/arch/m68knommu/platform/5272/senTec/crt0_ram.S | 159 +++++++++++++++++ 1 files changed, 159 insertions(+) diff -puN /dev/null arch/m68knommu/platform/5272/senTec/crt0_ram.S --- /dev/null Thu Apr 11 07:25:15 2002 +++ 25-akpm/arch/m68knommu/platform/5272/senTec/crt0_ram.S Fri Apr 9 14:33:41 2004 @@ -0,0 +1,159 @@ +/*****************************************************************************/ + +/* + * crt0_ram.S -- startup code for MCF5272 ColdFire based boards. + * + * (C) Copyright 1999-2002, Greg Ungerer (gerg@snapgear.com). + * (C) Copyright 2000, Lineo (www.lineo.com). + */ + +/*****************************************************************************/ + +#include +#include +#include +#include +#include +#include + +/*****************************************************************************/ + +/* + * senTec COBRA5272 board, chip select and memory setup. + */ + +#define MEM_BASE 0x00000000 /* Memory base at address 0 */ +#define VBR_BASE MEM_BASE /* Vector address */ + +#if defined(CONFIG_RAM16MB) +#define MEM_SIZE 0x01000000 /* Memory size 16Mb */ +#elif defined(CONFIG_RAM8MB) +#define MEM_SIZE 0x00800000 /* Memory size 8Mb */ +#else +#define MEM_SIZE 0x00400000 /* Memory size 4Mb */ +#endif + +/*****************************************************************************/ + +.global _start +.global _rambase +.global _ramvec +.global _ramstart +.global _ramend + +/*****************************************************************************/ + +.data + +/* + * Set up the usable of RAM stuff. Size of RAM is determined then + * an initial stack set up at the end. + */ +_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 */ + move.w #0x2700, %sr /* No interrupts */ + + /* + * Setup VBR here, otherwise buserror remap will not work. + * if dBug was active before (on my SBC with dBug 1.1 of Dec 16 1996) + * + * bkr@cut.de 19990306 + * + * Note: this is because dBUG points VBR to ROM, making vectors read + * only, so the bus trap can't be changed. (RS) + */ + move.l #VBR_BASE, %a7 /* Note VBR can't be read */ + movec %a7, %VBR + move.l %a7, _ramvec /* Set up vector addr */ + move.l %a7, _rambase /* Set up base RAM addr */ + + + /* + * Set memory size. + */ + move.l #MEM_SIZE, %a0 + + move.l %a0, %d0 /* Mem end addr is in a0 */ + move.l %d0, %sp /* Set up initial stack ptr */ + move.l %d0, _ramend /* Set end ram addr */ + + /* + * Enable CPU internal cache. + */ + move.l #0x01000000, %d0 /* Invalidate cache cmd */ + movec %d0, %CACR /* Invalidate cache */ + move.l #0x80000100, %d0 /* Setup cache mask */ + movec %d0, %CACR /* Enable cache */ + +#ifdef CONFIG_ROMFS_FS + /* + * Move ROM filesystem above bss :-) + */ + lea.l _sbss, %a0 /* Get start of bss */ + lea.l _ebss, %a1 /* Set up destination */ + move.l %a0, %a2 /* Copy of bss start */ + + move.l 8(%a0), %d0 /* Get size of ROMFS */ + addq.l #8, %d0 /* Allow for rounding */ + and.l #0xfffffffc, %d0 /* Whole words */ + + add.l %d0, %a0 /* Copy from end */ + add.l %d0, %a1 /* Copy from end */ + move.l %a1, _ramstart /* Set start of ram */ + +_copy_romfs: + move.l -(%a0), %d0 /* Copy dword */ + move.l %d0, -(%a1) + cmp.l %a0, %a2 /* Check if at end */ + bne _copy_romfs + +#else /* CONFIG_ROMFS_FS */ + lea.l _ebss, %a1 + move.l %a1, _ramstart +#endif /* CONFIG_ROMFS_FS */ + + + /* + * Zero out the bss region. + */ + lea.l _sbss, %a0 /* Get start of bss */ + lea.l _ebss, %a1 /* Get end of bss */ + clr.l %d0 /* Set value */ +_clear_bss: + move.l %d0, (%a0)+ /* Clear each word */ + cmp.l %a0, %a1 /* Check if at end */ + bne _clear_bss + + /* + * Load the current thread pointer and stack. + */ + lea init_thread_union, %a0 + lea 0x2000(%a0), %sp + + /* + * Assember start up done, start code proper. + */ + jsr start_kernel /* Start Linux kernel */ + +_exit: + jmp _exit /* Should never get here */ + +/*****************************************************************************/ _