apus_setup.c

这个linux源代码是很全面的~基本完整了~使用c编译的~由于时间问题我没有亲自测试~但就算用来做参考资料也是非常好的

/*********************************************************** CACHE */

#define L1_CACHE_BYTES 32
#define MAX_CACHE_SIZE 8192
void cache_push(__u32 addr, int length)
{
	addr = mm_ptov(addr);

	if (MAX_CACHE_SIZE < length)
		length = MAX_CACHE_SIZE;

	while(length > 0){
		__asm ("dcbf 0,%0\n\t"
		       : : "r" (addr));
		addr += L1_CACHE_BYTES;
		length -= L1_CACHE_BYTES;
	}
	/* Also flush trailing block */
	__asm ("dcbf 0,%0\n\t"
	       "sync \n\t"
	       : : "r" (addr));
}

void cache_clear(__u32 addr, int length)
{
	if (MAX_CACHE_SIZE < length)
		length = MAX_CACHE_SIZE;

	addr = mm_ptov(addr);

	__asm ("dcbf 0,%0\n\t"
	       "sync \n\t"
	       "icbi 0,%0 \n\t"
	       "isync \n\t"
	       : : "r" (addr));

	addr += L1_CACHE_BYTES;
	length -= L1_CACHE_BYTES;

	while(length > 0){
		__asm ("dcbf 0,%0\n\t"
		       "sync \n\t"
		       "icbi 0,%0 \n\t"
		       "isync \n\t"
		       : : "r" (addr));
		addr += L1_CACHE_BYTES;
		length -= L1_CACHE_BYTES;
	}

	__asm ("dcbf 0,%0\n\t"
	       "sync \n\t"
	       "icbi 0,%0 \n\t"
	       "isync \n\t"
	       : : "r" (addr));
}

/****************************************************** from setup.c */
void
apus_restart(char *cmd)
{
	cli();

	APUS_WRITE(APUS_REG_LOCK,
		   REGLOCK_BLACKMAGICK1|REGLOCK_BLACKMAGICK2);
	APUS_WRITE(APUS_REG_LOCK,
		   REGLOCK_BLACKMAGICK1|REGLOCK_BLACKMAGICK3);
	APUS_WRITE(APUS_REG_LOCK,
		   REGLOCK_BLACKMAGICK2|REGLOCK_BLACKMAGICK3);
	APUS_WRITE(APUS_REG_SHADOW, REGSHADOW_SELFRESET);
	APUS_WRITE(APUS_REG_RESET, REGRESET_AMIGARESET);
	for(;;);
}

void
apus_power_off(void)
{
	for (;;);
}

void
apus_halt(void)
{
   apus_restart(NULL);
}

/****************************************************** IRQ stuff */

static unsigned char last_ipl[8];

int apus_get_irq(struct pt_regs* regs)
{
	unsigned char ipl_emu, mask;
	unsigned int level;

	APUS_READ(APUS_IPL_EMU, ipl_emu);
	level = (ipl_emu >> 3) & IPLEMU_IPLMASK;
	mask = IPLEMU_SETRESET|IPLEMU_DISABLEINT|level;
	level ^= 7;

	/* Save previous IPL value */
	if (last_ipl[level])
		return -2;
	last_ipl[level] = ipl_emu;

	/* Set to current IPL value */
	APUS_WRITE(APUS_IPL_EMU, mask);
	APUS_WRITE(APUS_IPL_EMU, IPLEMU_DISABLEINT|level);


#ifdef __INTERRUPT_DEBUG
	printk("<%d:%d>", level, ~ipl_emu & IPLEMU_IPLMASK);
#endif
	return level + IRQ_AMIGA_AUTO;
}

void apus_end_irq(unsigned int irq)
{
	unsigned char ipl_emu;
	unsigned int level = irq - IRQ_AMIGA_AUTO;
#ifdef __INTERRUPT_DEBUG
	printk("{%d}", ~last_ipl[level] & IPLEMU_IPLMASK);
#endif
	/* Restore IPL to the previous value */
	ipl_emu = last_ipl[level] & IPLEMU_IPLMASK;
	APUS_WRITE(APUS_IPL_EMU, IPLEMU_SETRESET|IPLEMU_DISABLEINT|ipl_emu);
	last_ipl[level] = 0;
	ipl_emu ^= 7;
	APUS_WRITE(APUS_IPL_EMU, IPLEMU_DISABLEINT|ipl_emu);
}

/****************************************************** keyboard */
static int apus_kbd_setkeycode(unsigned int scancode, unsigned int keycode)
{
	return -EOPNOTSUPP;
}

static int apus_kbd_getkeycode(unsigned int scancode)
{
	return scancode > 127 ? -EINVAL : scancode;
}

static char apus_kbd_unexpected_up(unsigned char keycode)
{
	return 0200;
}

static void apus_kbd_init_hw(void)
{
#ifdef CONFIG_APUS
	extern int amiga_keyb_init(void);

	amiga_keyb_init();
#endif
}


/****************************************************** debugging */

/* some serial hardware definitions */
#define SDR_OVRUN   (1<<15)
#define SDR_RBF     (1<<14)
#define SDR_TBE     (1<<13)
#define SDR_TSRE    (1<<12)

#define AC_SETCLR   (1<<15)
#define AC_UARTBRK  (1<<11)

#define SER_DTR     (1<<7)
#define SER_RTS     (1<<6)
#define SER_DCD     (1<<5)
#define SER_CTS     (1<<4)
#define SER_DSR     (1<<3)

static __inline__ void ser_RTSon(void)
{
    ciab.pra &= ~SER_RTS; /* active low */
}

int __debug_ser_out( unsigned char c )
{
	custom.serdat = c | 0x100;
	mb();
	while (!(custom.serdatr & 0x2000))
		barrier();
	return 1;
}

unsigned char __debug_ser_in( void )
{
	unsigned char c;

	/* XXX: is that ok?? derived from amiga_ser.c... */
	while( !(custom.intreqr & IF_RBF) )
		barrier();
	c = custom.serdatr;
	/* clear the interrupt, so that another character can be read */
	custom.intreq = IF_RBF;
	return c;
}

int __debug_serinit( void )
{
	unsigned long flags;

	save_flags (flags);
	cli();

	/* turn off Rx and Tx interrupts */
	custom.intena = IF_RBF | IF_TBE;

	/* clear any pending interrupt */
	custom.intreq = IF_RBF | IF_TBE;

	restore_flags (flags);

	/*
	 * set the appropriate directions for the modem control flags,
	 * and clear RTS and DTR
	 */
	ciab.ddra |= (SER_DTR | SER_RTS);   /* outputs */
	ciab.ddra &= ~(SER_DCD | SER_CTS | SER_DSR);  /* inputs */

#ifdef CONFIG_KGDB
	/* turn Rx interrupts on for GDB */
	custom.intena = IF_SETCLR | IF_RBF;
	ser_RTSon();
#endif

	return 0;
}

void __debug_print_hex(unsigned long x)
{
	int i;
	char hexchars[] = "0123456789ABCDEF";

	for (i = 0; i < 8; i++) {
		__debug_ser_out(hexchars[(x >> 28) & 15]);
		x <<= 4;
	}
	__debug_ser_out('\n');
	__debug_ser_out('\r');
}

void __debug_print_string(char* s)
{
	unsigned char c;
	while((c = *s++))
		__debug_ser_out(c);
	__debug_ser_out('\n');
	__debug_ser_out('\r');
}

static void apus_progress(char *s, unsigned short value)
{
	__debug_print_string(s);
}

/****************************************************** init */

/* The number of spurious interrupts */
volatile unsigned int num_spurious;

extern struct irqaction amiga_sys_irqaction[AUTO_IRQS];


extern void amiga_enable_irq(unsigned int irq);
extern void amiga_disable_irq(unsigned int irq);

struct hw_interrupt_type amiga_sys_irqctrl = {
	typename: "Amiga IPL",
	end: apus_end_irq,
};

struct hw_interrupt_type amiga_irqctrl = {
	typename: "Amiga    ",
	enable: amiga_enable_irq,
	disable: amiga_disable_irq,
};

#define HARDWARE_MAPPED_SIZE (512*1024)
unsigned long __init apus_find_end_of_memory(void)
{
	int shadow = 0;
	unsigned long total;

	/* The memory size reported by ADOS excludes the 512KB
	   reserved for PPC exception registers and possibly 512KB
	   containing a shadow of the ADOS ROM. */
	{
		unsigned long size = memory[0].size;

		/* If 2MB aligned, size was probably user
                   specified. We can't tell anything about shadowing
                   in this case so skip shadow assignment. */
		if (0 != (size & 0x1fffff)){
			/* Align to 512KB to ensure correct handling
			   of both memfile and system specified
			   sizes. */
			size = ((size+0x0007ffff) & 0xfff80000);
			/* If memory is 1MB aligned, assume
                           shadowing. */
			shadow = !(size & 0x80000);
		}

		/* Add the chunk that ADOS does not see. by aligning
                   the size to the nearest 2MB limit upwards.  */
		memory[0].size = ((size+0x001fffff) & 0xffe00000);
	}

	total = memory[0].size;

	/* Remove the memory chunks that are controlled by special
           Phase5 hardware. */

	/* Remove the upper 512KB if it contains a shadow of
	   the ADOS ROM. FIXME: It might be possible to
	   disable this shadow HW. Check the booter
	   (ppc_boot.c) */
	if (shadow)
		total -= HARDWARE_MAPPED_SIZE;

	/* Remove the upper 512KB where the PPC exception
	   vectors are mapped. */
	total -= HARDWARE_MAPPED_SIZE;

	/* Linux/APUS only handles one block of memory -- the one on
	   the PowerUP board. Other system memory is horrible slow in
	   comparison. The user can use other memory for swapping
	   using the z2ram device. */
	ram_phys_base = memory[0].addr;
	return total;
}

static void __init
apus_map_io(void)
{
	/* Map PPC exception vectors. */
	io_block_mapping(0xfff00000, 0xfff00000, 0x00020000, _PAGE_KERNEL);
	/* Map chip and ZorroII memory */
	io_block_mapping(zTwoBase,   0x00000000, 0x01000000, _PAGE_IO);
}

__init
void apus_init_IRQ(void)
{
	struct irqaction *action;
	int i;

#ifdef CONFIG_PCI
        apus_setup_pci_ptrs();
#endif

	for ( i = 0 ; i < AMI_IRQS; i++ ) {
		irq_desc[i].status = IRQ_LEVEL;
		if (i < IRQ_AMIGA_AUTO) {
			irq_desc[i].handler = &amiga_irqctrl;
		} else {
			irq_desc[i].handler = &amiga_sys_irqctrl;
			action = &amiga_sys_irqaction[i-IRQ_AMIGA_AUTO];
			if (action->name)
				setup_irq(i, action);
		}
	}

	amiga_init_IRQ();

}

__init
void platform_init(unsigned long r3, unsigned long r4, unsigned long r5,
		   unsigned long r6, unsigned long r7)
{
	extern int parse_bootinfo(const struct bi_record *);
	extern char _end[];

	/* Parse bootinfo. The bootinfo is located right after
           the kernel bss */
	parse_bootinfo((const struct bi_record *)&_end);
#ifdef CONFIG_BLK_DEV_INITRD
	/* Take care of initrd if we have one. Use data from
	   bootinfo to avoid the need to initialize PPC
	   registers when kernel is booted via a PPC reset. */
	if ( ramdisk.addr ) {
		initrd_start = (unsigned long) __va(ramdisk.addr);
		initrd_end = (unsigned long)
			__va(ramdisk.size + ramdisk.addr);
	}
#endif /* CONFIG_BLK_DEV_INITRD */

	ISA_DMA_THRESHOLD = 0x00ffffff;

	ppc_md.setup_arch     = apus_setup_arch;
	ppc_md.show_cpuinfo   = apus_show_cpuinfo;
	ppc_md.init_IRQ       = apus_init_IRQ;
	ppc_md.get_irq        = apus_get_irq;

#ifdef CONFIG_HEARTBEAT
	ppc_md.heartbeat      = apus_heartbeat;
	heartbeat_reset(0)    = 1;		/* assume UP for now */
	heartbeat_count(0)    = 1;
#endif
#ifdef APUS_DEBUG
	__debug_serinit();
	ppc_md.progress       = apus_progress;
#endif
	ppc_md.init           = NULL;

	ppc_md.restart        = apus_restart;
	ppc_md.power_off      = apus_power_off;
	ppc_md.halt           = apus_halt;

	ppc_md.time_init      = NULL;
	ppc_md.set_rtc_time   = apus_set_rtc_time;
	ppc_md.get_rtc_time   = apus_get_rtc_time;
	ppc_md.calibrate_decr = apus_calibrate_decr;

	ppc_md.find_end_of_memory = apus_find_end_of_memory;
	ppc_md.setup_io_mappings = apus_map_io;

	/* These should not be used for the APUS yet, since it uses
	   the M68K keyboard now. */
	ppc_md.kbd_setkeycode    = apus_kbd_setkeycode;
	ppc_md.kbd_getkeycode    = apus_kbd_getkeycode;
	ppc_md.kbd_translate     = amiga_kbd_translate;
	ppc_md.kbd_unexpected_up = apus_kbd_unexpected_up;
	ppc_md.kbd_init_hw       = apus_kbd_init_hw;
#ifdef CONFIG_SYSRQ
	ppc_md.ppc_kbd_sysrq_xlate = amiga_sysrq_xlate;
	SYSRQ_KEY                = 0xff;
#endif
}