/* * 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/slab.h> #include <linux/string.h> #include <generated/utsrelease.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) void pal_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 void load(unsigned long dst, unsigned long src, unsigned long count) { memcpy((void *)dst, (void *)src, count); } /* * Start the kernel. */ static inline void runkernel(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) void start_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(); }