main.c

freebsd v4.4内核源码

/**************************************************************************
NETBOOT -  BOOTP/TFTP Bootstrap Program

Author: Martin Renters
  Date: Dec/93

**************************************************************************/

/* #define MDEBUG */

#include "netboot.h"

int	jmp_bootmenu[10];

struct	exec head;
char	*loadpoint;
char	*kernel;
char	kernel_buf[128];
void	(*kernelentry)();
struct	nfs_diskless nfsdiskless;
int	hostnamelen;
char	config_buffer[512];		/* Max TFTP packet */
struct	bootinfo bootinfo;
int	root_nfs_port;
unsigned long	netmask;
char	kernel_handle[32];
int 	offset, howto;

extern char eth_driver[];
extern	char packet[];
extern	int packetlen, rpc_id;
char	broadcast[] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };

/**************************************************************************
MAIN - Kick off routine
**************************************************************************/
main()
{
	int c;
	extern char edata[], end[];
	bzero(edata,end-edata);		/* Zero BSS */
#ifdef ASK_BOOT
	while (1) {
		printf("\nBoot from Network (Y/N) ? ");
		c = getchar();
		if ((c >= 'a') && (c <= 'z')) c &= 0x5F;
		if (c == '\r') break;
		putchar(c);
		if (c == 'N')
			exit(0);
		if (c == 'Y')
			break;
		printf(" - bad response\n\r");
	}
#endif

	/* get the bios's idea about the disks geometry */
	for(c = 0; c < N_BIOS_GEOM; c ++)
		bootinfo.bi_bios_geom[c] = get_diskinfo(c + 0x80);

	gateA20();
	printf("\nBOOTP/TFTP/NFS bootstrap loader    ESC for menu\n"
		"\nSearching for adapter...");
	if (!eth_probe()) {
		printf("No adapter found.\n");
		exit(0);
	}
	kernel = DEFAULT_BOOTFILE;
	while (1) {
		if (setjmp(jmp_bootmenu))
			bootmenu();
		else
			load();
	}
}

void
nfsload(length)
{
	int err, read_size;

	while (length > 0) {
		read_size = length > NFS_READ_SIZE ?
				NFS_READ_SIZE : length;
		if ((err = nfs_read(ARP_ROOTSERVER, root_nfs_port,
			&kernel_handle, offset, read_size, loadpoint)) !=
				read_size) {
			if (err < 0) {
				printf("Unable to read data: ");
				nfs_err(err);
			}
			longjmp(jmp_bootmenu, 1);
		}
		loadpoint += err;
		length -= err;
		offset += err;
	}
}

/**************************************************************************
LOAD - Try to get booted
**************************************************************************/
load()
{
	char	*p,*q;
	char	cfg[64];
	int	root_mount_port;
	int	swap_nfs_port;
	int	swap_mount_port;
	char	cmd_line[80];
	int	err, read_size, i;
	long	addr, broadcast;
	int	swsize;
	unsigned long pad;

	config_buffer[0]='\0'; /* clear; bootp might fill this up */
/* Initialize this early on */

        nfsdiskless.root_args.rsize = 8192;
        nfsdiskless.root_args.wsize = 8192;
        nfsdiskless.swap_args.rsize = 8192;
        nfsdiskless.swap_args.wsize = 8192;
        nfsdiskless.root_args.sotype = SOCK_DGRAM;
        nfsdiskless.root_args.flags = (NFSMNT_WSIZE | NFSMNT_RSIZE | 
				       NFSMNT_RESVPORT);
        nfsdiskless.swap_args.sotype = SOCK_DGRAM;
        nfsdiskless.swap_args.flags = (NFSMNT_WSIZE | NFSMNT_RSIZE | 
				       NFSMNT_RESVPORT);


		/* Find a server to get BOOTP reply from */
	if (!arptable[ARP_CLIENT].ipaddr || !arptable[ARP_SERVER].ipaddr) {
		printf("\r\nSearching for server...\r\n");
		if (!bootp()) {
			printf("No Server found.\r\n");
			longjmp(jmp_bootmenu,1);
		}
	}
	printf("My IP %I, Server IP %I, GW IP %I\r\n",
		arptable[ARP_CLIENT].ipaddr,
		arptable[ARP_SERVER].ipaddr,
		arptable[ARP_GATEWAY].ipaddr);

#ifdef MDEBUG
	printf("\n=>>"); getchar();
#endif

	/*** check if have got info from bootp ***/
	if (config_buffer[0])
		goto cfg_done;
#ifndef NO_TFTP
	/* Now use TFTP to load configuration file */
	sprintf(cfg,"/tftpboot/freebsd.%I",arptable[ARP_CLIENT].ipaddr);
	if (tftp(cfg) || tftp(cfg+10))
		goto cfg_done;
	cfg[17]='\0';
	if (tftp(cfg) || tftp(cfg+10))
		goto cfg_done;
	sprintf(cfg,"/tftpboot/cfg.%I",arptable[ARP_CLIENT].ipaddr);
	if (tftp(cfg) || tftp(cfg+10))
		goto cfg_done;
#endif
	/* not found; using default values... */
	sprintf(config_buffer,"rootfs %I:/usr/diskless_root",
		arptable[ARP_SERVER].ipaddr);
	printf("Unable to load config file, guessing:\r\n\t%s\r\n",
		config_buffer);

cfg_done:
#ifdef MDEBUG
	printf("\n=>>"); getchar();
#endif

	p = config_buffer;
	while(*p) {
		q = cmd_line;
		while ((*p != '\n') && (*p)) *(q++) = *(p++);
		*q = 0;
		printf("%s\r\n",cmd_line);
		execute(cmd_line);
		if (*p) p++;
	}

#ifdef MDEBUG
	printf("\n=>>"); getchar();
#endif

		/* Check to make sure we've got a rootfs */
	if (!arptable[ARP_ROOTSERVER].ipaddr) {
		printf("No ROOT filesystem server!\r\n");
		longjmp(jmp_bootmenu,1);
	}

		/* Fill in nfsdiskless.myif */
	sprintf(&nfsdiskless.myif.ifra_name,eth_driver);
        nfsdiskless.myif.ifra_addr.sa_len = sizeof(struct sockaddr);
        nfsdiskless.myif.ifra_addr.sa_family = AF_INET;
	addr = htonl(arptable[ARP_CLIENT].ipaddr);
	bcopy(&addr, &nfsdiskless.myif.ifra_addr.sa_data[2], 4);
	broadcast = (addr & netmask) | ~netmask;
	nfsdiskless.myif.ifra_broadaddr.sa_len = sizeof(struct sockaddr);
	nfsdiskless.myif.ifra_broadaddr.sa_family = AF_INET;
	bcopy(&broadcast, &nfsdiskless.myif.ifra_broadaddr.sa_data[2], 4);
	addr = htonl(arptable[ARP_GATEWAY].ipaddr);
	if (addr) {
		nfsdiskless.mygateway.sin_len = sizeof(struct sockaddr);
		nfsdiskless.mygateway.sin_family = AF_INET;
		bcopy(&addr, &nfsdiskless.mygateway.sin_addr, 4);
	} else {
		nfsdiskless.mygateway.sin_len = 0;
	}
	nfsdiskless.myif.ifra_mask.sa_len = sizeof(struct sockaddr);
	nfsdiskless.myif.ifra_mask.sa_family = AF_UNSPEC;
	bcopy(&netmask, &nfsdiskless.myif.ifra_mask.sa_data[2], 4);

	rpc_id = currticks();

		/* Lookup NFS/MOUNTD ports for SWAP using PORTMAP */
	if (arptable[ARP_SWAPSERVER].ipaddr) {
		char swapfs_fh[32], swapfile[32];
		swap_nfs_port = rpclookup(ARP_SWAPSERVER, PROG_NFS, 2);
		swap_mount_port = rpclookup(ARP_SWAPSERVER, PROG_MOUNT, 1);
		if ((swap_nfs_port == -1) || (swap_mount_port == -1)) {
			printf("Unable to get SWAP NFS/MOUNT ports\r\n");
			longjmp(jmp_bootmenu,1);
		}
		if (err = nfs_mount(ARP_SWAPSERVER, swap_mount_port,
			nfsdiskless.swap_hostnam, &swapfs_fh)) {
			printf("Unable to mount SWAP filesystem: ");
			nfs_err(err);
			longjmp(jmp_bootmenu,1);
		}
		sprintf(swapfile,"swap.%I",arptable[ARP_CLIENT].ipaddr);
		if (err = nfs_lookup(ARP_SWAPSERVER, swap_nfs_port,
			&swapfs_fh, swapfile, &nfsdiskless.swap_fh, &swsize)) {
			printf("Unable to open %s: ",swapfile);
			nfs_err(err);
			longjmp(jmp_bootmenu,1);
		}
		if (!nfsdiskless.swap_nblks) {
		  nfsdiskless.swap_nblks = swsize / 1024;
		  printf("Swap size is: %d blocks\n",nfsdiskless.swap_nblks);
		}
		nfsdiskless.swap_saddr.sin_len = sizeof(struct sockaddr_in);
		nfsdiskless.swap_saddr.sin_family = AF_INET;
		nfsdiskless.swap_saddr.sin_port = htons(swap_nfs_port);
		nfsdiskless.swap_saddr.sin_addr.s_addr =
			htonl(arptable[ARP_SWAPSERVER].ipaddr);
        	nfsdiskless.swap_args.timeo = 10;
        	nfsdiskless.swap_args.retrans = 100;
	}

		/* Lookup NFS/MOUNTD ports for ROOT using PORTMAP */
	root_nfs_port = rpclookup(ARP_ROOTSERVER, PROG_NFS, 2);
	root_mount_port = rpclookup(ARP_ROOTSERVER, PROG_MOUNT, 1);
	if ((root_nfs_port == -1) || (root_mount_port == -1)) {
		printf("Unable to get ROOT NFS/MOUNT ports\r\n");
		longjmp(jmp_bootmenu,1);
	}
	if (err = nfs_mount(ARP_ROOTSERVER, root_mount_port,
		nfsdiskless.root_hostnam, &nfsdiskless.root_fh)) {
		printf("Unable to mount ROOT filesystem: ");
		nfs_err(err);
		longjmp(jmp_bootmenu,1);
	}
	nfsdiskless.root_saddr.sin_len = sizeof(struct sockaddr_in);
	nfsdiskless.root_saddr.sin_family = AF_INET;
	nfsdiskless.root_saddr.sin_port = htons(root_nfs_port);
	nfsdiskless.root_saddr.sin_addr.s_addr =
		htonl(arptable[ARP_ROOTSERVER].ipaddr);
        nfsdiskless.root_args.timeo = 10;
        nfsdiskless.root_args.retrans = 100;
	nfsdiskless.root_time = 0;

	if (err = nfs_lookup(ARP_ROOTSERVER, root_nfs_port,
		&nfsdiskless.root_fh, *kernel == '/' ? kernel+1 : kernel,
		&kernel_handle, NULL)) {
		printf("Unable to open %s: ",kernel);
		nfs_err(err);
		longjmp(jmp_bootmenu,1);
	}

		/* Load the kernel using NFS */
	printf("Loading %s...\r\n",kernel);
	if ((err = nfs_read(ARP_ROOTSERVER, root_nfs_port, &kernel_handle, 0,
		sizeof(struct exec), &head)) < 0) {
		printf("Unable to read %s: ",kernel);
		nfs_err(err);
		longjmp(jmp_bootmenu,1);
	}
	if (N_BADMAG(head)) {
		printf("Bad executable format!\r\n");
		longjmp(jmp_bootmenu, 1);
	}
	loadpoint = (char *)0x100000;
	offset = N_TXTOFF(head);
	printf("text=0x%X, ",head.a_text);
	nfsload(head.a_text);
	while (((int)loadpoint) & PAGE_MASK)
		*(loadpoint++) = 0;

	printf("data=0x%X, ",head.a_data);
	nfsload(head.a_data);

	printf("bss=0x%X, ",head.a_bss);
	while(head.a_bss--) *(loadpoint++) = 0;

	while (((int)loadpoint) & PAGE_MASK)
		*(loadpoint++) = 0;

	bootinfo.bi_symtab = (int) loadpoint;

	p = (char*)&head.a_syms;
	for (i=0;i<sizeof(head.a_syms);i++)
		*loadpoint++ = *p++;

	printf("symbols=[+0x%x+0x%x", sizeof(head.a_syms), head.a_syms);
	
	nfsload(head.a_syms);
	i = sizeof(int);
	p = loadpoint;
	nfsload(i);
	i = *(int*)p;
	printf("+0x%x]\n", i);
	i -= sizeof(int);
	nfsload(i);
	bootinfo.bi_esymtab = (int) loadpoint;

	printf("entry=0x%X.\n\r",head.a_entry);

		/* Jump to kernel */
	bootinfo.bi_version = BOOTINFO_VERSION;
	bootinfo.bi_kernelname = kernel;
	bootinfo.bi_nfs_diskless = &nfsdiskless;
	bootinfo.bi_size = sizeof bootinfo;
	kernelentry = (void *)(head.a_entry & 0x00FFFFFF);
	(*kernelentry)(howto|RB_BOOTINFO,NODEV,0,0,0,&bootinfo,0,0,0);
	printf("*** %s execute failure ***\n",kernel);
}

/**************************************************************************
POLLKBD - Check for Interrupt from keyboard
**************************************************************************/
pollkbd()
{
	if (iskey() && (getchar() == ESC)) longjmp(jmp_bootmenu,1);
}

/**************************************************************************
DEFAULT_NETMASK - Set a default netmask for IP address
**************************************************************************/