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/*

 * 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 int vsprintf(char *, const char *, va_list);

extern unsigned long switch_to_osf_pal(unsigned long nr,

        struct pcb_struct * pcb_va, struct pcb_struct * pcb_pa,

        unsigned long vptb, unsigned long *kstk);

int printk(const char * fmt, ...)

{

        va_list args;

        int i, j, written, remaining, num_nl;

        static char buf[1024];

        char * str;

        va_start(args, fmt);

        i = vsprintf(buf, fmt, args);

        va_end(args);

        /* expand \n into \r\n: */

        num_nl = 0;

        for (j = 0; j < i; ++j) {

            if (buf[j] == '\n')

                ++num_nl;

        }

        remaining = i + num_nl;

        for (j = i - 1; j >= 0; --j) {

            buf[j + num_nl] = buf[j];

            if (buf[j] == '\n') {

                --num_nl;

                buf[j + num_nl] = '\r';

            }

        }

        str = buf;

        do {

            written = puts(str, remaining);

            remaining -= written;

            str += written;

        } while (remaining > 0);

        return i;

}

#define hwrpb (*INIT_HWRPB)

/*

 * Find a physical address of a virtual object..

 *

 * This is easy using the virtual page table address.

 */

struct pcb_struct * find_pa(unsigned long *vptb, struct pcb_struct * pcb)

{

        unsigned long address = (unsigned long) pcb;

        unsigned long result;

        result = vptb[address >> 13];

        result >>= 32;

        result <<= 13;

        result |= address & 0x1fff;

        return (struct pcb_struct *) 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.

 *

 * As we don't want it there anyway, we also move the L1 self-map

 * up as high as we can, so that the last entry in the L1 page table

 * maps the page tables.

 *

 * As a result, the OSF/1 pal-code will instead use a virtual page table

 * map located at 0xffffffe00000000.

 */

#define pcb_va ((struct pcb_struct *) 0x20000000)

#define old_vptb (0x0000000200000000UL)

#define new_vptb (0xfffffffe00000000UL)

void pal_init(void)

{

        unsigned long i, rev, sum;

        unsigned long *L1, *l;

        struct percpu_struct * percpu;

        struct pcb_struct * pcb_pa;

        /* Find the level 1 page table and duplicate it in high memory */

        L1 = (unsigned long *) 0x200802000UL; /* (1<<33 | 1<<23 | 1<<13) */

        L1[1023] = L1[1];

        percpu = (struct percpu_struct *)

                        (hwrpb.processor_offset + (unsigned long) &hwrpb),

        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_pa = find_pa((unsigned long *) old_vptb, pcb_va);

        printk("Switching to OSF PAL-code .. ");

        /*

         * 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 we give it 0, asm sets it)

         */

        i = switch_to_osf_pal(

                2,

                pcb_va,

                pcb_pa,

                new_vptb,

                0);

        if (i) {

                printk("failed, code %ld\n", i);

                halt();

        }

        rev = percpu->pal_revision = percpu->palcode_avail[2];

        hwrpb.vptb = new_vptb;

        /* update checksum: */

        sum = 0;

        for (l = (unsigned long *) &hwrpb;

             l < (unsigned long *) &hwrpb.chksum;

             ++l)

                sum += *l;

        hwrpb.chksum = sum;

        printk("Ok (rev %lx)\n", rev);

        /* remove the old virtual page-table mapping */

        L1[1] = 0;

        flush_tlb_all();

}

static inline long load(unsigned long dst,

                        unsigned long src,

                        unsigned long count)

{

        extern void * memcpy(void *, const void *, size_t);

        memcpy((void *)dst, (void *)src, count);

        return count;

}

/*

 * 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));

}

extern char _end;

#define KERNEL_ORIGIN \

        ((((unsigned long)&_end) + 511) & ~511)

void start_kernel(void)

{

        static long i;

        static int nbytes;

        static char envval[256];

        char envbuf[256];

        printk("Linux/AXP bootp loader for Linux " UTS_RELEASE "\n");

        if (hwrpb.pagesize != 8192) {

                printk("Expected 8kB pages, got %ldkB\n",

                       hwrpb.pagesize >> 10);

                return;

        }

        pal_init();

        nbytes = dispatch(CCB_GET_ENV, ENV_BOOTED_OSFLAGS,

                          envbuf, sizeof(envbuf));

        if (nbytes < 0 || nbytes >= sizeof(envbuf)) {

                nbytes = 0;

        }

        envbuf[nbytes] = '\0';

        memcpy(envval, envbuf, nbytes+1);

        printk("Loading the kernel...'%s'\n", envval);

        /* NOTE: *no* callbacks or printouts from here on out!!! */

        /*

         * HACK alert:

         *

         * assume direct copy will fail due to overlap of virtual source

         * and physical destination, so move it way high physical first,

         * then move it back to its final resting place...

         *

         * this way could fail, too, but it works on the platforms *I* have

         */

        i = load(START_ADDR+(4*KERNEL_SIZE), KERNEL_ORIGIN, KERNEL_SIZE);

        i = load(START_ADDR, START_ADDR+(4*KERNEL_SIZE), KERNEL_SIZE);

        strcpy((char*)ZERO_PAGE, envval);

        runkernel();

        for (i = 0 ; i < 0x100000000 ; i++)

                /* nothing */;

        halt();

}