// SPDX-License-Identifier: GPL-2.0/* * arch/alpha/boot/main.c * * Copyright (C) 1994, 1995 Linus Torvalds * * This file is the bootloader for the Linux/AXP kernel */#include <linux/kernel.h>#include <linux/slab.h>#include <linux/string.h>#include <generated/utsrelease.h>#include <linux/mm.h> #include <asm/console.h>#include <asm/hwrpb.h> #include <linux/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);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 long openboot(void){	char bootdev[256];	long result; 	result = callback_getenv(ENV_BOOTED_DEV, bootdev, 255);	if (result < 0)		return result;	return callback_open(bootdev, result & 255);} static inline long close(long dev){	return callback_close(dev);} static inline long load(long dev, unsigned long addr, unsigned long count){	char bootfile[256];	extern char _end;	long result, boot_size = &_end - (char *) BOOT_ADDR; 	result = callback_getenv(ENV_BOOTED_FILE, bootfile, 255);	if (result < 0)		return result;	result &= 255;	bootfile[result] = '\0';	if (result)		srm_printk("Boot file specification (%s) not implemented\n",		       bootfile);	return callback_read(dev, count, (void *)addr, boot_size/512 + 1);} /* * Start the kernel. */static void runkernel(void){	__asm__ __volatile__(		"bis %1,%1,$30\n\t"		"bis %0,%0,$26\n\t"		"ret ($26)"		: /* no outputs: it doesn't even return */		: "r" (START_ADDR),		  "r" (PAGE_SIZE + INIT_STACK));} void start_kernel(void){	long i;	long dev;	int nbytes;	char envval[256]; 	srm_printk("Linux/AXP bootloader for Linux " UTS_RELEASE "\n");	if (INIT_HWRPB->pagesize != 8192) {		srm_printk("Expected 8kB pages, got %ldkB\n", INIT_HWRPB->pagesize >> 10);		return;	}	pal_init();	dev = openboot();	if (dev < 0) {		srm_printk("Unable to open boot device: %016lx\n", dev);		return;	}	dev &= 0xffffffff;	srm_printk("Loading vmlinux ...");	i = load(dev, START_ADDR, KERNEL_SIZE);	close(dev);	if (i != KERNEL_SIZE) {		srm_printk("Failed (%lx)\n", i);		return;	} 	nbytes = callback_getenv(ENV_BOOTED_OSFLAGS, envval, sizeof(envval));	if (nbytes < 0) {		nbytes = 0;	}	envval[nbytes] = '\0';	strcpy((char*)ZERO_PGE, envval); 	srm_printk(" Ok\nNow booting the kernel\n");	runkernel();	for (i = 0 ; i < 0x100000000 ; i++)		/* nothing */;	__halt();}