source: rtems/bsps/powerpc/motorola_powerpc/bootloader/misc.c

/*
 *  head.S -- Bootloader Entry point
 *
 *  Copyright (C) 1998, 1999 Gabriel Paubert, paubert@iram.es
 *
 *  Modified to compile in RTEMS development environment
 *  by Eric Valette
 *
 *  Copyright (C) 1999 Eric Valette. valette@crf.canon.fr
 *
 *  The license and distribution terms for this file may be
 *  found in the file LICENSE in this distribution or at
 *  http://www.rtems.org/license/LICENSE.
 */

#include <sys/param.h>
#include <sys/types.h>
#include <string.h>
#include "bootldr.h"
#include <libcpu/spr.h>
#include "zlib.h"
#include <libcpu/byteorder.h>
#include <rtems/bspIo.h>
#include <bsp.h>

#include <rtems.h>

/* to align the pointer to the (next) page boundary */
#define PAGE_ALIGN(addr)        (((addr) + PAGE_MASK) & ~PAGE_MASK)

SPR_RO(PPC_PVR)

struct inode;
struct wait_queue;
struct buffer_head;
typedef struct { int counter; } atomic_t;

typedef struct page {
        /* these must be first (free area handling) */
        struct page *next;
        struct page *prev;
        struct inode *inode;
        unsigned long offset;
        struct page *next_hash;
        atomic_t count;
        unsigned long flags;    /* atomic flags, some possibly updated asynchronously */
        struct wait_queue *wait;
        struct page **pprev_hash;
        struct buffer_head * buffers;
} mem_map_t;

extern opaque mm_private, pci_private, v86_private, console_private;

#define CONSOLE_ON_SERIAL       "console=ttyS0"

extern struct console_io vacuum_console_functions;
extern opaque log_console_setup, serial_console_setup, vga_console_setup;

boot_data __bd = {0, 0, 0, 0, 0, 0, 0, 0,
                  32, 0, 0, 0, 0, 0, 0,
                  &mm_private,
                  NULL,
                  &pci_private,
                  NULL,
                  &v86_private,
                  "root=/dev/hdc1"
                 };

static void exit(void) __attribute__((noreturn));

static void exit(void) {
        printk("\nOnly way out is to press the reset button!\n");
        asm volatile("": : :"memory");
        while(1);
}

void hang(const char *s, u_long x, ctxt *p) {
        u_long *r1;
#ifdef DEBUG
        print_all_maps("\nMemory mappings at exception time:\n");
#endif
        printk("%s %lx NIP: %p LR: %p\n"
               "Callback trace (stack:return address)\n",
               s, x, (void *) p->nip, (void *) p->lr);
        asm volatile("lwz %0,0(1); lwz %0,0(%0); lwz %0,0(%0)": "=b" (r1));
        while(r1) {
                printk("  %p:%p\n", r1, (void *) r1[1]);
                r1 = (u_long *) *r1;
        }
        exit();
};

static void *zalloc(void *x, unsigned items, unsigned size)
{
        void *p = salloc(items*size);

        if (!p) {
                printk("oops... not enough memory for gunzip\n");
        }
        return p;
}

static void zfree(void *x, void *addr, unsigned nb)
{
        sfree(addr);
}

#define HEAD_CRC        2
#define EXTRA_FIELD     4
#define ORIG_NAME       8
#define COMMENT         0x10
#define RESERVED        0xe0

#define DEFLATED        8

void gunzip(void *dst, int dstlen, unsigned char *src, int *lenp)
{
        z_stream s;
        int r, i, flags;

        /* skip header */
        i = 10;
        flags = src[3];
        if (src[2] != DEFLATED || (flags & RESERVED) != 0) {
                printk("bad gzipped data\n");
                exit();
        }
        if ((flags & EXTRA_FIELD) != 0)
                i = 12 + src[10] + (src[11] << 8);
        if ((flags & ORIG_NAME) != 0)
                while (src[i++] != 0)
                        ;
        if ((flags & COMMENT) != 0)
                while (src[i++] != 0)
                        ;
        if ((flags & HEAD_CRC) != 0)
                i += 2;
        if (i >= *lenp) {
                printk("gunzip: ran out of data in header\n");
                exit();
        }

        s.zalloc = zalloc;
        s.zfree = zfree;
        r = inflateInit2(&s, -MAX_WBITS);
        if (r != Z_OK) {
                printk("inflateInit2 returned %d\n", r);
                exit();
        }
        s.next_in = src + i;
        s.avail_in = *lenp - i;
        s.next_out = dst;
        s.avail_out = dstlen;
        r = inflate(&s, Z_FINISH);
        if (r != Z_OK && r != Z_STREAM_END) {
                printk("inflate returned %d\n", r);
                exit();
        }
        *lenp = s.next_out - (unsigned char *) dst;
        inflateEnd(&s);
}

void decompress_kernel(int kernel_size, void * zimage_start, int len,
                       void * initrd_start, int initrd_len ) {
        u_char *parea;
        RESIDUAL* rescopy;
        int zimage_size= len;

        /* That's a mess, we have to copy the residual data twice just in
         * case it happens to be in the low memory area where the kernel
         * is going to be unpacked. Later we have to copy it back to
         * lower addresses because only the lowest part of memory is mapped
         * during boot.
         */
        parea=__palloc(kernel_size, PA_LOW);
        if(!parea) {
                printk("Not enough memory to uncompress the kernel.");
                exit();
        }

        rescopy=salloc(sizeof(RESIDUAL));
        /* Let us hope that residual data is aligned on word boundary */
        *rescopy =  *bd->residual;
        bd->residual = (void *)PAGE_ALIGN(kernel_size);

        /* Note that this clears the bss as a side effect, so some code
         * with ugly special case for SMP could be removed from the kernel!
         */
        memset(parea, 0, kernel_size);
        printk("\nUncompressing the kernel...\n");

        gunzip(parea, kernel_size, zimage_start, &zimage_size);

        bd->of_entry = 0;
        bd->load_address = 0;
        bd->r6 = (char *)bd->residual+PAGE_ALIGN(sizeof(RESIDUAL));
        bd->r7 = bd->r6+strlen(bd->cmd_line);
        if ( initrd_len ) {
                /* We have to leave some room for the hash table and for the
                 * whole array of struct page. The hash table would be better
                 * located at the end of memory if possible. With some bridges
                 * DMA from the last pages of memory is slower because
                 * prefetching from PCI has to be disabled to avoid accessing
                 * non existing memory. So it is the ideal place to put the
                 * hash table.
                 */
                unsigned tmp = rescopy->TotalMemory;
                /* It's equivalent to tmp & (-tmp), but using the negation
                 * operator on unsigned variables looks so ugly.
                 */
                if ((tmp & (~tmp+1)) != tmp) tmp <<= 1; /* Next power of 2 */
                tmp /= 256; /* Size of hash table */
                if (tmp> (2<<20)) tmp=2<<20;
                tmp = tmp*2 + 0x40000; /* Alignment can double size + 256 kB */
                tmp += (rescopy->TotalMemory / PAGE_SIZE)
                               * sizeof(struct page);
                bd->load_address = (void *)PAGE_ALIGN((int)bd->r7 + tmp);
                bd->of_entry = (char *)bd->load_address+initrd_len;
        }
#ifdef DEBUG
        printk("Kernel at 0x%p, size=0x%x\n", NULL, kernel_size);
        printk("Initrd at 0x%p, size=0x%x\n",bd->load_address, initrd_len);
        printk("Residual data at 0x%p\n", bd->residual);
        printk("Command line at 0x%p\n",bd->r6);
#endif
        printk("done\nNow booting...\n");
        MMUoff();       /* We need to access address 0 ! */
        codemove(0, parea, kernel_size, bd->cache_lsize);
        codemove(bd->residual, rescopy, sizeof(RESIDUAL), bd->cache_lsize);
        codemove(bd->r6, bd->cmd_line, sizeof(bd->cmd_line), bd->cache_lsize);
        /* codemove checks for 0 length */
        codemove(bd->load_address, initrd_start, initrd_len, bd->cache_lsize);
}

static int ticks_per_ms=0;

/*
 * This is based on rtems_bsp_delay from libcpu
 */
void
boot_udelay(uint32_t _microseconds)
{
   uint32_t   start, ticks, now;

   ticks = _microseconds * ticks_per_ms / 1000;
   CPU_Get_timebase_low( start );
   do {
     CPU_Get_timebase_low( now );
   } while (now - start < ticks);
}

void
setup_hw(void)
{
        char *cp, ch;
        register RESIDUAL * res;
        /* PPC_DEVICE * nvram; */
        struct pci_dev *default_vga;
        int timer, err;
        u_short default_vga_cmd;

        res=bd->residual;
        default_vga=NULL;
        default_vga_cmd = 0;

#define vpd res->VitalProductData
        if (_read_PPC_PVR()>>16 != 1) {
                if ( res && vpd.ProcessorBusHz ) {
                        ticks_per_ms = vpd.ProcessorBusHz/
                            (vpd.TimeBaseDivisor ? vpd.TimeBaseDivisor : 4000);
                } else {
                        ticks_per_ms = 16500; /* assume 66 MHz on bus */
                }
        }

        select_console(CONSOLE_LOG);

        /* We check that the keyboard is present and immediately
         * select the serial console if not.
         */
#if defined(BSP_KBD_IOBASE)
        err = kbdreset();
        if (err) select_console(CONSOLE_SERIAL);
#else
        err = 1;
        select_console(CONSOLE_SERIAL);
#endif

        printk("\nModel: %s\nSerial: %s\n"
               "Processor/Bus frequencies (Hz): %ld/%ld\n"
               "Time Base Divisor: %ld\n"
               "Memory Size: %lx\n"
                   "Residual: %lx (length %lu)\n",
               vpd.PrintableModel,
               vpd.Serial,
               vpd.ProcessorHz,
               vpd.ProcessorBusHz,
               (vpd.TimeBaseDivisor ? vpd.TimeBaseDivisor : 4000),
               res->TotalMemory,
               (unsigned long)res,
               res->ResidualLength);

        /* This reconfigures all the PCI subsystem */
        pci_init();

        /* The Motorola NT firmware does not set the correct mem size */
        if ( vpd.FirmwareSupplier == 0x10000 ) {
                int memsize;
                memsize = find_max_mem(bd->pci_devices);
                if ( memsize != res->TotalMemory ) {
                        printk("Changed Memory size from %lx to %x\n",
                                res->TotalMemory, memsize);
                        res->TotalMemory = memsize;
                        res->GoodMemory = memsize;
                }
        }
#define ENABLE_VGA_USAGE
#undef ENABLE_VGA_USAGE
#ifdef ENABLE_VGA_USAGE
        /* Find the primary VGA device, chosing the first one found
         * if none is enabled. The basic loop structure has been copied
         * from linux/drivers/char/bttv.c by Alan Cox.
         */
        for (p = bd->pci_devices; p; p = p->next) {
                u_short cmd;
                if (p->class != PCI_CLASS_NOT_DEFINED_VGA &&
                    ((p->class) >> 16 != PCI_BASE_CLASS_DISPLAY))
                        continue;
                if (p->bus->number != 0) {
                        printk("VGA device not on bus 0 not initialized!\n");
                        continue;
                }
                /* Only one can be active in text mode, which for now will
                 * be assumed as equivalent to having I/O response enabled.
                 */
                pci_bootloader_read_config_word(p, PCI_COMMAND, &cmd);
                if(cmd & PCI_COMMAND_IO || !default_vga) {
                        default_vga=p;
                        default_vga_cmd=cmd;
                }
        }

        /* Disable the enabled VGA device, if any. */
        if (default_vga)
                pci_bootloader_write_config_word(default_vga, PCI_COMMAND,
                                      default_vga_cmd&
                                      ~(PCI_COMMAND_IO|PCI_COMMAND_MEMORY));
        init_v86();
        /* Same loop copied from bttv.c, this time doing the serious work */
        for (p = bd->pci_devices; p; p = p->next) {
                u_short cmd;
                if (p->class != PCI_CLASS_NOT_DEFINED_VGA &&
                    ((p->class) >> 16 != PCI_BASE_CLASS_DISPLAY))
                        continue;
                if (p->bus->number != 0) continue;
                pci_bootloader_read_config_word(p, PCI_COMMAND, &cmd);
                pci_bootloader_write_config_word(p, PCI_COMMAND,
                                      cmd|PCI_COMMAND_IO|PCI_COMMAND_MEMORY);
                printk("Calling the emulator.\n");
                em86_main(p);
                pci_bootloader_write_config_word(p, PCI_COMMAND, cmd);
        }

        cleanup_v86_mess();
#endif
        /* Reenable the primary VGA device */
        if (default_vga) {
                pci_bootloader_write_config_word(default_vga, PCI_COMMAND,
                                      default_vga_cmd|
                                      (PCI_COMMAND_IO|PCI_COMMAND_MEMORY));
                if (err) {
                        printk("Keyboard error %d, using serial console!\n",
                               err);
                } else {
                        select_console(CONSOLE_VGA);
                }
        } else if (!err) {
                select_console(CONSOLE_SERIAL);
                if (bd->cmd_line[0] == '\0') {
                  strcat(&bd->cmd_line[0], CONSOLE_ON_SERIAL);
                }
                else {
                  int s = strlen (bd->cmd_line);
                  bd->cmd_line[s + 1] = ' ';
                  bd->cmd_line[s + 2] = '\0';
                  strcat(&bd->cmd_line[0], CONSOLE_ON_SERIAL);
                }
        }
#if 0
        /* In the future we may use the NVRAM to store default
         * kernel parameters.
         */
        nvram=residual_find_device(~0UL, NULL, SystemPeripheral, NVRAM,
                                   ~0UL, 0);
        if (nvram) {
                PnP_TAG_PACKET * pkt;
                switch (nvram->DevId.Interface) {
                case IndirectNVRAM:
                          pkt=PnP_find_packet(res->DevicePnpHeap
                                      +nvram->AllocatedOffset,
                                              )
                }
        }
#endif

        printk("\nRTEMS " RTEMS_VERSION "/PPC load: ");
        timer = 0;
        cp = bd->cmd_line+strlen(bd->cmd_line);
        while (timer++ < 5*1000) {
                if (debug_tstc()) {
                        while ((ch = debug_getc()) != '\n' && ch != '\r') {
                                if (ch == '\b' || ch == 0177) {
                                        if (cp != bd->cmd_line) {
                                                cp--;
                                                printk("\b \b");
                                        }
                                } else {
                                        *cp++ = ch;
                                        debug_putc(ch);
                                }
                        }
                        break;  /* Exit 'timer' loop */
                }
                boot_udelay(1000);  /* 1 msec */
        }
        *cp = 0;
}

/* Functions to deal with the residual data */
static int same_DevID(unsigned short vendor,
               unsigned short Number,
               unsigned char * str)
{
        static unsigned const char hexdigit[]="0123456789ABCDEF";
        if (strlen((char*)str)!=7) return 0;
        if ( ( ((vendor>>10)&0x1f)+'A'-1 == str[0])  &&
             ( ((vendor>>5)&0x1f)+'A'-1 == str[1])   &&
             ( (vendor&0x1f)+'A'-1 == str[2])        &&
             (hexdigit[(Number>>12)&0x0f] == str[3]) &&
             (hexdigit[(Number>>8)&0x0f] == str[4])  &&
             (hexdigit[(Number>>4)&0x0f] == str[5])  &&
             (hexdigit[Number&0x0f] == str[6]) ) return 1;
        return 0;
}

PPC_DEVICE *residual_find_device(unsigned long BusMask,
                         unsigned char * DevID,
                         int BaseType,
                         int SubType,
                         int Interface,
                         int n)
{
        int i;
        RESIDUAL *res = bd->residual;
        if ( !res || !res->ResidualLength ) return NULL;
        for (i=0; i<res->ActualNumDevices; i++) {
#define Dev res->Devices[i].DeviceId
                if ( (Dev.BusId&BusMask)                                  &&
                     (BaseType==-1 || Dev.BaseType==BaseType)             &&
                     (SubType==-1 || Dev.SubType==SubType)                &&
                     (Interface==-1 || Dev.Interface==Interface)          &&
                     (DevID==NULL || same_DevID((Dev.DevId>>16)&0xffff,
                                                Dev.DevId&0xffff, DevID)) &&
                     !(n--) ) return res->Devices+i;
#undef Dev
        }
        return 0;
}

PnP_TAG_PACKET *PnP_find_packet(unsigned char *p,
                                unsigned packet_tag,
                                int n)
{
        unsigned mask, masked_tag, size;
        if(!p) return 0;
        if (tag_type(packet_tag)) mask=0xff; else mask=0xF8;
        masked_tag = packet_tag&mask;
        for(; *p != END_TAG; p+=size) {
                if ((*p & mask) == masked_tag && !(n--))
                        return (PnP_TAG_PACKET *) p;
                if (tag_type(*p))
                        size=ld_le16((unsigned short *)(p+1))+3;
                else
                        size=tag_small_count(*p)+1;
        }
        return 0; /* not found */
}

PnP_TAG_PACKET *PnP_find_small_vendor_packet(unsigned char *p,
                                             unsigned packet_type,
                                             int n)
{
        int next=0;
        while (p) {
                p = (unsigned char *) PnP_find_packet(p, 0x70, next);
                if (p && p[1]==packet_type && !(n--))
                        return (PnP_TAG_PACKET *) p;
                next = 1;
        };
        return 0; /* not found */
}

PnP_TAG_PACKET *PnP_find_large_vendor_packet(unsigned char *p,
                                           unsigned packet_type,
                                           int n)
{
        int next=0;
        while (p) {
                p = (unsigned char *) PnP_find_packet(p, 0x84, next);
                if (p && p[3]==packet_type && !(n--))
                        return (PnP_TAG_PACKET *) p;
                next = 1;
        };
        return 0; /* not found */
}

/* Find out the amount of installed memory. For MPC105 and IBM 660 this
 * can be done by finding the bank with the highest memory ending address
 */
int
find_max_mem( struct pci_dev *dev )
{
        u_char banks,tmp;
        int i, top, max;

        max = 0;
        for ( ; dev; dev = dev->next) {
                if ( ((dev->vendor == PCI_VENDOR_ID_MOTOROLA) &&
                      (dev->device == PCI_DEVICE_ID_MOTOROLA_MPC105)) ||
                     ((dev->vendor == PCI_VENDOR_ID_IBM) &&
                      (dev->device == 0x0037/*IBM 660 Bridge*/)) ) {
                        pci_bootloader_read_config_byte(dev, 0xa0, &banks);
                        for (i = 0; i < 8; i++) {
                                if ( banks & (1<<i) ) {
                                        pci_bootloader_read_config_byte(dev, 0x90+i, &tmp);
                                        top = tmp;
                                        pci_bootloader_read_config_byte(dev, 0x98+i, &tmp);
                                        top |= (tmp&3)<<8;
                                        if ( top > max ) max = top;
                                }
                        }
                        if ( max ) return ((max+1)<<20);
                        else return(0);
                }
        }
        return(0);
}