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#include <std.h>
#include <memory.h>
#include <type.h>
#include <error.h>

#define MP_SIGL 0x5f504d5f
#define MP_SIGSTR "_MP_"

#define MP_CONFIG_SIGL 0x504d4350
#define MP_CONFIG_SIGSTR "PCMP"

struct mp {
	u8 sig[4];
	u32 config_ptr;
	u8 len;
	u8 ver;
	u8 checksum;
	u8 f1;
	u8 f2;
	u8 fr[3];
}__attribute__((packed))*mp;

struct mp_config {
	u8 sig[4];
	u16 len;
	u8 ver;
	u8 checksum;
	u8 oem_id[8];
	u8 prod_id[12];
	u32 oem_ptr;	/*For an optional oem table*/
	u16 oem_sz;
	u16 nr_entries;
	u32 lapic_addr;
	u16 ext_len;
	u8 ext_checksum;
}__attribute__((packed))*mp_config;

#define ENT_PROC 0
#define ENT_BUS 1
#define ENT_IOAPIC 2
#define ENT_IOINTA 3	 /*IO interrupt assignment*/
#define ENT_LINTA 4		/*Local interrupt assignment*/


/*A processor entry*/
struct mp_proc {
	u8 type;
	u8 lapic_id;
	u8 lapic_ver;
	u8 flags; /*bit0:enabled proc, bit1:bootstrap*/
	u32 sig;
	u32 feat;
	u8 resvd[8];
}__attribute__((packed));

/*ioapic entry*/
struct mp_ioapic {
	u8 type;
	u8 id;
	u8 ver;
	u8 flags; /*bit0: enabled ioapic*/
	u32 addr;
}__attribute__((packed));

#define MP_PROC_SZ 20
#define MP_IOAPIC_SZ 8
#define MP_BUS_SZ 8
#define MP_IOINTA_SZ 8
#define MP_LINTA_SZ 8

struct processor {
	struct mp_proc *proc; /*Note:This points to actual entry by BIOS. We have not made a local copy*/
	struct processor *next;
}*processors=NULL;

struct ioapic {
	struct mp_ioapic *ioapic;
	struct ioapic *next;
}*ioapics=NULL;

/*This is just a local linked list, nothing to do with the bios tables*/
/*Add a processor to the linked list*/
int add_processor(struct mp_proc *x)
{
	struct processor *tail;
	if(!((x->flags) & 1)) {/*Disabled*/
		return NULL;
	}
	if(x->flags & 2) /*Bootstrap*/
		printk(":boot");
	if(!processors) {
		processors=new(struct processor);
		processors->next=NULL;
		tail=processors;
	} else {
		for(tail=processors;tail->next;tail=tail->next);
		tail->next=new(struct processor);
		tail=tail->next;
		tail->next=NULL;
	}
	tail->proc=x;
	return NULL;
}

/*Add an ioapic to the linked list*/
int add_ioapic(struct mp_ioapic *x)
{
	struct ioapic *tail;
	if(!ioapics) {
		ioapics=new(struct ioapic);
		ioapics->next=NULL;
		tail=ioapics;
	} else {
		for(tail=ioapics;tail->next;tail=tail->next);
		tail->next=new(struct ioapic);
		tail=tail->next;
		tail->next=NULL;
	}
	tail->ioapic=x;
	return NULL;
}

/*Build list by scanning the entries after the config table*/
int build_list()
{
	int i;
	u8 *ent;
	struct mp_proc *proc;
	struct mp_ioapic *ioapic;
	mp_config=(struct mp_config *)mp->config_ptr;
	if((*((u32 *)mp_config->sig))!=MP_CONFIG_SIGL)
		return ELLERR;
	printk("PCMP %x",mp_config); /*found a PCMP*/
	ent=(char *)((u32)mp_config+sizeof(struct mp_config)); /*Go to the array of entries*/
	for(i=0;i<mp_config->nr_entries;i++) {
		switch(ent[0]) { /*Read the type*/
			case ENT_PROC:
				printk(".proc");
				add_processor((struct mp_proc *)ent);
				ent+=MP_PROC_SZ;
				break;
			case ENT_BUS:
				printk(".bus");
				ent+=MP_BUS_SZ;
				break;
			case ENT_IOAPIC:
				printk(".ioapic");
				add_ioapic((struct mp_ioapic *)ent);
				ent+=MP_IOAPIC_SZ;
				break;
			case ENT_IOINTA:
				printk(".iointa");
				ent+=MP_IOINTA_SZ;
				break;
			case ENT_LINTA:
				printk(".linta");
				ent+=MP_LINTA_SZ;
				break;
			default:
				goto inv_exit;
		}
	}
	inv_exit:
	return NULL;
}

int compute_checksum(char *b,int sz)
{
	int i;
	unsigned char c=0;
	for(i=0;i<sz;i++) {
		c+=b[i];
	}
	return (int)c;
}

#define EBDA_START 0x40E
#define EBDA_SEARCH_SZ 0x400

#define BASE_START 0xa0000
#define BASE_SEARCH_SZ 0x400

#define ROM_START 0xf0000
#define ROM_END 0x100000
/*Search for the mp floating pointer in the above 3 areas*/
int search_mp()
{
	u32 *i=NULL;
	int c;
	for(i=0;(u32)i<0x400;i++) { /*RAM start 1k*/
		if(*i==MP_SIGL) {
			mp=(struct mp *)i;
			return NULL;
		}
	}
	for(i=EBDA_START;(u32)i<EBDA_START+EBDA_SEARCH_SZ;i++) {
		if(*i==MP_SIGL) {
			mp=(struct mp *)i;
			return NULL;
		}
	}
	for(i=BASE_START;(u32)i<BASE_START+BASE_SEARCH_SZ;i++) {
		if(*i==MP_SIGL) {
			mp=(struct mp *)i;
			return NULL;
		}
	}
	for(i=ROM_START;(u32)i<ROM_END;i++) {
		if(*i==MP_SIGL) {
			mp=(struct mp *)i;
			return NULL;
		}
	}
	return ENODEV;
}


int init_smp()
{
	if(!search_mp()) {
		printk("\n_MP_,");
		build_list(); /*Build a linked list of procs and ioapics*/
		return NULL;
	}
}