/* * arch/alpha/boot/bootp.c * * Copyright (C) 1997 Jay Estabrook * * This file is used for creating a bootp file for the Linux/AXP kernel * * based significantly on the arch/alpha/boot/main.c of Linus Torvalds */#include <linux/kernel.h>#include <linux/string.h>#include <linux/version.h>#include <linux/mm.h>#include <asm/system.h>#include <asm/console.h>#include <asm/hwrpb.h>#include <asm/pgtable.h>#include <asm/io.h>#include <stdarg.h>#include "ksize.h"extern unsigned long switch_to_osf_pal(unsigned long nr,	struct pcb_struct * pcb_va, struct pcb_struct * pcb_pa,	unsigned long *vptb);extern void move_stack(unsigned long new_stack);struct hwrpb_struct *hwrpb = INIT_HWRPB;static struct pcb_struct pcb_va[1];/* * Find a physical address of a virtual object.. * * This is easy using the virtual page table address. */static inline void *find_pa(unsigned long *vptb, void *ptr){	unsigned long address = (unsigned long) ptr;	unsigned long result;	result = vptb[address >> 13];	result >>= 32;	result <<= 13;	result |= address & 0x1fff;	return (void *) result;}	/* * This function moves into OSF/1 pal-code, and has a temporary * PCB for that. The kernel proper should replace this PCB with * the real one as soon as possible. * * The page table muckery in here depends on the fact that the boot * code has the L1 page table identity-map itself in the second PTE * in the L1 page table. Thus the L1-page is virtually addressable * itself (through three levels) at virtual address 0x200802000. */#define VPTB	((unsigned long *) 0x200000000)#define L1	((unsigned long *) 0x200802000)voidpal_init(void){	unsigned long i, rev;	struct percpu_struct * percpu;	struct pcb_struct * pcb_pa;	/* Create the dummy PCB.  */	pcb_va->ksp = 0;	pcb_va->usp = 0;	pcb_va->ptbr = L1[1] >> 32;	pcb_va->asn = 0;	pcb_va->pcc = 0;	pcb_va->unique = 0;	pcb_va->flags = 1;	pcb_va->res1 = 0;	pcb_va->res2 = 0;	pcb_pa = find_pa(VPTB, pcb_va);	/*	 * a0 = 2 (OSF)	 * a1 = return address, but we give the asm the vaddr of the PCB	 * a2 = physical addr of PCB	 * a3 = new virtual page table pointer	 * a4 = KSP (but the asm sets it)	 */	srm_printk("Switching to OSF PAL-code .. ");	i = switch_to_osf_pal(2, pcb_va, pcb_pa, VPTB);	if (i) {		srm_printk("failed, code %ld\n", i);		__halt();	}	percpu = (struct percpu_struct *)		(INIT_HWRPB->processor_offset + (unsigned long) INIT_HWRPB);	rev = percpu->pal_revision = percpu->palcode_avail[2];	srm_printk("Ok (rev %lx)\n", rev);	tbia(); /* do it directly in case we are SMP */}static inline voidload(unsigned long dst, unsigned long src, unsigned long count){	memcpy((void *)dst, (void *)src, count);}/* * Start the kernel. */static inline voidrunkernel(void){	__asm__ __volatile__(		"bis %0,%0,$27\n\t"		"jmp ($27)"		: /* no outputs: it doesn't even return */		: "r" (START_ADDR));}extern char _end;#define KERNEL_ORIGIN \	((((unsigned long)&_end) + 511) & ~511)voidstart_kernel(void){	/*	 * Note that this crufty stuff with static and envval	 * and envbuf is because:	 *	 * 1. Frequently, the stack is short, and we don't want to overrun;	 * 2. Frequently the stack is where we are going to copy the kernel to;	 * 3. A certain SRM console required the GET_ENV output to stack.	 *    ??? A comment in the aboot sources indicates that the GET_ENV	 *    destination must be quadword aligned.  Might this explain the	 *    behaviour, rather than requiring output to the stack, which	 *    seems rather far-fetched.	 */	static long nbytes;	static char envval[256] __attribute__((aligned(8)));	static unsigned long initrd_start;	srm_printk("Linux/AXP bootp loader for Linux " UTS_RELEASE "\n");	if (INIT_HWRPB->pagesize != 8192) {		srm_printk("Expected 8kB pages, got %ldkB\n",		           INIT_HWRPB->pagesize >> 10);		return;	}	if (INIT_HWRPB->vptb != (unsigned long) VPTB) {		srm_printk("Expected vptb at %p, got %p\n",			   VPTB, (void *)INIT_HWRPB->vptb);		return;	}	pal_init();	/* The initrd must be page-aligned.  See below for the 	   cause of the magic number 5.  */	initrd_start = ((START_ADDR + 5*KERNEL_SIZE + PAGE_SIZE) |			(PAGE_SIZE-1)) + 1;#ifdef INITRD_IMAGE_SIZE	srm_printk("Initrd positioned at %#lx\n", initrd_start);#endif	/*	 * Move the stack to a safe place to ensure it won't be	 * overwritten by kernel image.	 */	move_stack(initrd_start - PAGE_SIZE);	nbytes = callback_getenv(ENV_BOOTED_OSFLAGS, envval, sizeof(envval));	if (nbytes < 0 || nbytes >= sizeof(envval)) {		nbytes = 0;	}	envval[nbytes] = '\0';	srm_printk("Loading the kernel...'%s'\n", envval);	/* NOTE: *no* callbacks or printouts from here on out!!! */	/* This is a hack, as some consoles seem to get virtual 20000000 (ie	 * where the SRM console puts the kernel bootp image) memory	 * overlapping physical memory where the kernel wants to be put,	 * which causes real problems when attempting to copy the former to	 * the latter... :-(	 *	 * So, we first move the kernel virtual-to-physical way above where	 * we physically want the kernel to end up, then copy it from there	 * to its final resting place... ;-}	 *	 * Sigh...  */#ifdef INITRD_IMAGE_SIZE	load(initrd_start, KERNEL_ORIGIN+KERNEL_SIZE, INITRD_IMAGE_SIZE);#endif        load(START_ADDR+(4*KERNEL_SIZE), KERNEL_ORIGIN, KERNEL_SIZE);        load(START_ADDR, START_ADDR+(4*KERNEL_SIZE), KERNEL_SIZE);	memset((char*)ZERO_PGE, 0, PAGE_SIZE);	strcpy((char*)ZERO_PGE, envval);#ifdef INITRD_IMAGE_SIZE	((long *)(ZERO_PGE+256))[0] = initrd_start;	((long *)(ZERO_PGE+256))[1] = INITRD_IMAGE_SIZE;#endif	runkernel();}