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Diffstat (limited to 'arch/alpha/boot/bootp.c')
-rw-r--r-- | arch/alpha/boot/bootp.c | 214 |
1 files changed, 214 insertions, 0 deletions
diff --git a/arch/alpha/boot/bootp.c b/arch/alpha/boot/bootp.c new file mode 100644 index 000000000..00266e6e1 --- /dev/null +++ b/arch/alpha/boot/bootp.c @@ -0,0 +1,214 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * 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/console.h> +#include <asm/hwrpb.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(); +} |