cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

main.c (4332B)

      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * arch/alpha/boot/main.c
      4 *
      5 * Copyright (C) 1994, 1995 Linus Torvalds
      6 *
      7 * This file is the bootloader for the Linux/AXP kernel
      8 */
      9#include <linux/kernel.h>
     10#include <linux/slab.h>
     11#include <linux/string.h>
     12#include <generated/utsrelease.h>
     13#include <linux/mm.h>
     14
     15#include <asm/console.h>
     16#include <asm/hwrpb.h>
     17
     18#include <stdarg.h>
     19
     20#include "ksize.h"
     21
     22extern unsigned long switch_to_osf_pal(unsigned long nr,
     23	struct pcb_struct * pcb_va, struct pcb_struct * pcb_pa,
     24	unsigned long *vptb);
     25struct hwrpb_struct *hwrpb = INIT_HWRPB;
     26static struct pcb_struct pcb_va[1];
     27
     28/*
     29 * Find a physical address of a virtual object..
     30 *
     31 * This is easy using the virtual page table address.
     32 */
     33
     34static inline void *
     35find_pa(unsigned long *vptb, void *ptr)
     36{
     37	unsigned long address = (unsigned long) ptr;
     38	unsigned long result;
     39
     40	result = vptb[address >> 13];
     41	result >>= 32;
     42	result <<= 13;
     43	result |= address & 0x1fff;
     44	return (void *) result;
     45}	
     46
     47/*
     48 * This function moves into OSF/1 pal-code, and has a temporary
     49 * PCB for that. The kernel proper should replace this PCB with
     50 * the real one as soon as possible.
     51 *
     52 * The page table muckery in here depends on the fact that the boot
     53 * code has the L1 page table identity-map itself in the second PTE
     54 * in the L1 page table. Thus the L1-page is virtually addressable
     55 * itself (through three levels) at virtual address 0x200802000.
     56 */
     57
     58#define VPTB	((unsigned long *) 0x200000000)
     59#define L1	((unsigned long *) 0x200802000)
     60
     61void
     62pal_init(void)
     63{
     64	unsigned long i, rev;
     65	struct percpu_struct * percpu;
     66	struct pcb_struct * pcb_pa;
     67
     68	/* Create the dummy PCB.  */
     69	pcb_va->ksp = 0;
     70	pcb_va->usp = 0;
     71	pcb_va->ptbr = L1[1] >> 32;
     72	pcb_va->asn = 0;
     73	pcb_va->pcc = 0;
     74	pcb_va->unique = 0;
     75	pcb_va->flags = 1;
     76	pcb_va->res1 = 0;
     77	pcb_va->res2 = 0;
     78	pcb_pa = find_pa(VPTB, pcb_va);
     79
     80	/*
     81	 * a0 = 2 (OSF)
     82	 * a1 = return address, but we give the asm the vaddr of the PCB
     83	 * a2 = physical addr of PCB
     84	 * a3 = new virtual page table pointer
     85	 * a4 = KSP (but the asm sets it)
     86	 */
     87	srm_printk("Switching to OSF PAL-code .. ");
     88
     89	i = switch_to_osf_pal(2, pcb_va, pcb_pa, VPTB);
     90	if (i) {
     91		srm_printk("failed, code %ld\n", i);
     92		__halt();
     93	}
     94
     95	percpu = (struct percpu_struct *)
     96		(INIT_HWRPB->processor_offset + (unsigned long) INIT_HWRPB);
     97	rev = percpu->pal_revision = percpu->palcode_avail[2];
     98
     99	srm_printk("Ok (rev %lx)\n", rev);
    100
    101	tbia(); /* do it directly in case we are SMP */
    102}
    103
    104static inline long openboot(void)
    105{
    106	char bootdev[256];
    107	long result;
    108
    109	result = callback_getenv(ENV_BOOTED_DEV, bootdev, 255);
    110	if (result < 0)
    111		return result;
    112	return callback_open(bootdev, result & 255);
    113}
    114
    115static inline long close(long dev)
    116{
    117	return callback_close(dev);
    118}
    119
    120static inline long load(long dev, unsigned long addr, unsigned long count)
    121{
    122	char bootfile[256];
    123	extern char _end;
    124	long result, boot_size = &_end - (char *) BOOT_ADDR;
    125
    126	result = callback_getenv(ENV_BOOTED_FILE, bootfile, 255);
    127	if (result < 0)
    128		return result;
    129	result &= 255;
    130	bootfile[result] = '\0';
    131	if (result)
    132		srm_printk("Boot file specification (%s) not implemented\n",
    133		       bootfile);
    134	return callback_read(dev, count, (void *)addr, boot_size/512 + 1);
    135}
    136
    137/*
    138 * Start the kernel.
    139 */
    140static void runkernel(void)
    141{
    142	__asm__ __volatile__(
    143		"bis %1,%1,$30\n\t"
    144		"bis %0,%0,$26\n\t"
    145		"ret ($26)"
    146		: /* no outputs: it doesn't even return */
    147		: "r" (START_ADDR),
    148		  "r" (PAGE_SIZE + INIT_STACK));
    149}
    150
    151void start_kernel(void)
    152{
    153	long i;
    154	long dev;
    155	int nbytes;
    156	char envval[256];
    157
    158	srm_printk("Linux/AXP bootloader for Linux " UTS_RELEASE "\n");
    159	if (INIT_HWRPB->pagesize != 8192) {
    160		srm_printk("Expected 8kB pages, got %ldkB\n", INIT_HWRPB->pagesize >> 10);
    161		return;
    162	}
    163	pal_init();
    164	dev = openboot();
    165	if (dev < 0) {
    166		srm_printk("Unable to open boot device: %016lx\n", dev);
    167		return;
    168	}
    169	dev &= 0xffffffff;
    170	srm_printk("Loading vmlinux ...");
    171	i = load(dev, START_ADDR, KERNEL_SIZE);
    172	close(dev);
    173	if (i != KERNEL_SIZE) {
    174		srm_printk("Failed (%lx)\n", i);
    175		return;
    176	}
    177
    178	nbytes = callback_getenv(ENV_BOOTED_OSFLAGS, envval, sizeof(envval));
    179	if (nbytes < 0) {
    180		nbytes = 0;
    181	}
    182	envval[nbytes] = '\0';
    183	strcpy((char*)ZERO_PGE, envval);
    184
    185	srm_printk(" Ok\nNow booting the kernel\n");
    186	runkernel();
    187	for (i = 0 ; i < 0x100000000 ; i++)
    188		/* nothing */;
    189	__halt();
    190}