arch/sparc/kernel/head.S

/* */
   1 /* boot.S: The initial boot code for the Sparc port of Linux.
   2 
   3    Copyright (C) 1994 David S. Miller (davem@caip.rutgers.edu)
   4 
   5            This file has to serve three purposes.
   6 
   7            1) determine the prom-version and cpu/architecture
   8            2) print enough useful info before we start to execute
   9               c-code that I can possibly begin to debug things
  10            3) Hold the vector of trap entry points
  11 
  12    The Sparc offers many challenges to kernel design. Here I will
  13    document those I have come across thus far. Upon bootup the boot
  14    prom loads your a.out image into memory. This memory the prom has
  15    already mapped for you in two places, however as far as I can tell
  16    the virtual address cache is not turned on although the MMU is
  17    translating things. You get loaded at 0x4000 exactly and you are
  18    aliased to 0xf8004000 with the appropriate mmu entries. So, when
  19    you link a boot-loadable object you want to do something like:
  20 
  21         ld -e start -Ttext 4000 -o mykernel myobj1.o myobj2.o ....
  22 
  23    to produce a proper image.
  24 
  25    At boot time you are given (as far as I can tell at this time)
  26    one key to figure out what machine you are one and what devices
  27    are available. The prom when it loads you leaves a pointer to
  28    the 'rom vector' in register %o0 right before it jumps to your
  29    starting address. This is a pointer to a struct that is full of
  30    pointer to functions (ie. printf, halt, reboot), pointers to
  31    linked lists (ie. memory mappings), and pointer to empirical
  32    constants (ie. stdin and stdout magic cookies + rom version).
  33    Starting with this piece of information you can figure out 
  34    just about anything you want about the machine you are on.
  35 
  36    Although I don't use it now, if you are on a Multiprocessor and
  37    therefore a v3 or above prom, register %o2 at boot contains a
  38    function pointer you must call before you proceed to invoke the
  39    other cpu's on the machine. I have no idea what kind of magic this
  40    is, give me time.
  41 */
  42 
  43 #include <asm/cprefix.h>
  44 #include <asm/head.h>
  45 #include <asm/version.h>
  46 #include <asm/asi.h>
  47 #include <asm/contregs.h>
  48 #include <asm/psr.h>
  49 #include <asm/page.h>
  50 
  51         .data
  52 
  53 /* First thing to go in the data segment is the interrupt stack. */
  54 
  55         .globl  C_LABEL(intstack)
  56         .globl  C_LABEL(eintstack)
  57 C_LABEL(intstack):
  58         .skip   4 * PAGE_SIZE                ! 16k = 128 128-byte stack frames
  59 C_LABEL(eintstack):
  60 
  61 
  62 
  63 /* 
  64    The following are used with the prom_vector node-ops to figure out
  65    the cpu-type 
  66 */
  67 
  68         .globl  C_LABEL(cputyp)
  69 
  70 C_LABEL(cputyp):
  71         .word   1
  72 
  73 C_LABEL(cputypval):
  74         .asciz "sun4c"
  75         .ascii "     "
  76 
  77         .align 4
  78 /*
  79  * Sun people can't spell worth damn. "compatability" indeed.
  80  * At least we *know* we can't spell, and use a spell-checker.
  81  */
  82 
  83 /* Uh, actually Linus it is I who cannot spell. Too much murky
  84  * Sparc assembly will do this to ya.
  85  */
  86 C_LABEL(cputypvar):
  87         .asciz "compatability"
  88 
  89 C_LABEL(cputypvallen) = C_LABEL(cputypvar) - C_LABEL(cputypval)
  90 
  91 /* This hold the prom-interface-version number for either v0 or v2. */
  92 
  93         .align 4
  94         .globl  C_LABEL(prom_iface_vers)
  95 
  96 C_LABEL(prom_iface_vers):       .skip 4
  97 
  98 /* WARNING: evil messages follow */
  99 
 100         .align 4
 101 
 102 sun4_notsup:
 103         .asciz  "Sparc-Linux: sun4 support not implemented yet\n\n"
 104         .align 4
 105 
 106 sun4m_notsup:
 107         .asciz  "Sparc-Linux: sun4m support does not exist\n\n"
 108         .align 4
 109 
 110 sun4d_notsup:
 111         .asciz  "Sparc-Linux: sun4d support does not exist\n\n"
 112         .align 4
 113 
 114 you_lose:
 115         .asciz  "You lose..... Thanks for playing...\n"
 116         .align 4
 117 
 118 
 119         .globl boot_msg
 120 
 121 /* memory descriptor property strings, v2 = yuk yuk yuk  */
 122 /* XXX how to figure out vm mapped by prom? May have to scan magic addresses */
 123 
 124 mem_prop_physavail:     .asciz "available"
 125         
 126                         .align 4
 127 mem_prop_phystot:       .asciz "reg"
 128 
 129 /* v2_memory descriptor struct kludged here for assembly, if it ain't broke */
 130 
 131                 .align 4
 132 v2_mem_struct:  .skip 0xff
 133 
 134                         .align 4
 135 v2_printf_physavail:    .asciz "Physical Memory Available: 0x%x bytes"
 136         
 137                         .align 4
 138 v2_printf_phystot:      .asciz "Physical Memory: 0x%x bytes"
 139 
 140 /* A place to store property strings returned from the prom 'node' funcs */
 141 
 142                         .align 4
 143 prop_string_buf:        .skip 32
 144 
 145                 .align 4
 146 prop_name:      .asciz "name"
 147         
 148                 .align 4
 149 current_node:   .skip 4
 150 
 151 
 152 /* nice little boot message */
 153 
 154                 .align 4
 155 boot_msg:       
 156         .ascii "Booting Sparc-Linux V0.00PRE-ALPHA "
 157         .ascii WHO_COMPILED_ME 
 158         .asciz " \n"
 159         .align 4
 160 
 161         .globl boot_msg2
 162 
 163 boot_msg2:
 164         .asciz "Booting Sparclinux V0.00 PRE-ALPHA on a (SUN4C)\n\n"
 165 
 166         .align 4
 167 
 168 pstring1:
 169         .asciz "Prom Magic Cookie: 0x%x  \n"
 170         .align 4
 171 
 172 pstring2:
 173         .asciz "Interface Version: v%d\n"
 174         .align 4
 175 
 176 pstring3:
 177         .asciz "Prom Revision: V%d\n\n"
 178         .align 4
 179 
 180 pstring4:
 181         .ascii "Total Physical Memory: %d bytes\nVM mapped by Prom: %d bytes\n"
 182         .asciz "Available Physical Memory: %d bytes\n"
 183         .align 4
 184 
 185 
 186         .text
 187 
 188         .globl  C_LABEL(msgbuf)
 189 msgbufsize = PAGE_SIZE                       ! 1 page for msg buffer
 190 C_LABEL(msgbuf) =  PAGE_SIZE
 191 
 192 
 193 IE_reg_addr = C_LABEL(msgbuf) + msgbufsize   ! this page not used; points to IEreg
 194 
 195         
 196 /* Ok, things start to get interesting. We get linked such that 'start'
 197    is the entry symbol. However, it is real low in kernel address space
 198    and as such a nifty place to place the trap table. We achieve this goal
 199    by just jumping to 'gokernel' for the first trap's entry as the sparc
 200    never receives the zero trap as it is real special (hw reset).
 201 
 202    Each trap entry point is the size of 4 sparc instructions (or 4 bytes
 203    * 4 insns = 16 bytes). There are 128 hardware traps (some undefined
 204    or unimplemented) and 128 software traps (sys-calls, etc.).
 205 
 206    One of the instructions must be a branch. More often than not this
 207    will be to a trap handler entry point because it is completely
 208    impossible to handle any trap in 4 insns. I welcome anyone to 
 209    challenge this theory. :-)
 210 
 211    On entry into this table the hardware has loaded the program counter
 212    at which the trap occurred into register %l1 and the next program
 213    counter into %l2, this way we can return from the trap with a simple
 214 
 215            jmp %l1; rett %l2  ! poof...
 216 
 217    after properly servicing the trap. It wouldn't be a bad idea to load
 218    some more information into the local regs since we have technically
 219    2 or 3 instructions to play with besides the jmp to the 'real' trap
 220    handler (one can even go in the delay slot). For now I am going to put
 221    the %psr (processor status register) and the trap-type value in %l0
 222    and %l3 respectively. Also, for IRQ's I'll put the level in %l4.
 223 
 224 */
 225 
 226         .globl  start
 227         .globl  _start  /* warning, solaris hack */
 228         .globl  C_LABEL(trapbase)
 229 _start:   /* danger danger */
 230 start:
 231 C_LABEL(trapbase):
 232         b gokernel; nop; nop; nop;      ! we never get trap #0 it is special 
 233 
 234         TRAP_ENTRY(0x1, my_trap_handler) /* Instruction Access Exception */
 235         TRAP_ENTRY(0x2, my_trap_handler) /* Illegal Instruction */
 236         TRAP_ENTRY(0x3, my_trap_handler) /* Privileged Instruction */
 237         TRAP_ENTRY(0x4, my_trap_handler) /* Floating Point Disabled */
 238         TRAP_ENTRY(0x5, spill_window_entry)   /* Window Overflow */
 239         TRAP_ENTRY(0x6, fill_window_entry)  /* Window Underflow */
 240         TRAP_ENTRY(0x7, my_trap_handler) /* Memory Address Not Aligned */
 241         TRAP_ENTRY(0x8, my_trap_handler) /* Floating Point Exception */
 242         TRAP_ENTRY(0x9, my_trap_handler) /* Data Miss Exception */
 243         TRAP_ENTRY(0xa, my_trap_handler) /* Tagged Instruction Overflow */
 244         TRAP_ENTRY(0xb, my_trap_handler) /* Watchpoint Detected */
 245         TRAP_ENTRY(0xc, my_trap_handler) /* Undefined... */
 246         TRAP_ENTRY(0xd, my_trap_handler) /* Undefined... */
 247         TRAP_ENTRY(0xe, my_trap_handler) /* Undefined... */
 248         TRAP_ENTRY(0xf, my_trap_handler) /* Undefined... */
 249         TRAP_ENTRY(0x10, my_trap_handler) /* Undefined... */
 250 
 251 /* Level'd interrupt entry points, see macro defs above */
 252 
 253         TRAP_ENTRY_INTERRUPT_SOFT(1, 0x101) /* Interrupt Level 1  */
 254         TRAP_ENTRY_INTERRUPT(2)             /* Interrupt Level 2  */
 255         TRAP_ENTRY_INTERRUPT(3)             /* Interrupt Level 3  */
 256         TRAP_ENTRY_INTERRUPT_SOFT(4, 0x104) /* Interrupt Level 4  */
 257         TRAP_ENTRY_INTERRUPT(5)             /* Interrupt Level 5  */
 258         TRAP_ENTRY_INTERRUPT_SOFT(6, 0x106) /* Interrupt Level 6  */
 259         TRAP_ENTRY_INTERRUPT(7)             /* Interrupt Level 7  */
 260         TRAP_ENTRY_INTERRUPT(8)             /* Interrupt Level 8  */
 261         TRAP_ENTRY_INTERRUPT(9)             /* Interrupt Level 9  */
 262         TRAP_ENTRY_INTERRUPT(10)            /* Interrupt Level 10 */
 263         TRAP_ENTRY_INTERRUPT(11)            /* Interrupt Level 11 */
 264         TRAP_ENTRY_INTERRUPT(12)            /* Interrupt Level 12 */
 265         TRAP_ENTRY_INTERRUPT(13)            /* Interrupt Level 13 */
 266         TRAP_ENTRY(0x27, sparc_timer)       /* Interrupt Level 14 */
 267         TRAP_ENTRY_INTERRUPT_NMI(15, linux_trap_nmi) /* Level 15 (nmi) */
 268 
 269         TRAP_ENTRY(0x20, my_trap_handler)   /* General Register Access Error */
 270         TRAP_ENTRY(0x21, my_trap_handler)   /* Instruction Access Error      */
 271         TRAP_ENTRY(0x22, my_trap_handler)   /* Undefined...                  */
 272         TRAP_ENTRY(0x23, my_trap_handler)   /* Undefined...                  */
 273         TRAP_ENTRY(0x24, my_trap_handler)   /* Co-Processor Disabled         */
 274         TRAP_ENTRY(0x25, my_trap_handler)   /* Unimplemented FLUSH inst.     */
 275         TRAP_ENTRY(0x26, my_trap_handler)   /* Undefined...                  */
 276         TRAP_ENTRY(0x27, my_trap_handler)   /* Undefined...                  */
 277         TRAP_ENTRY(0x28, my_trap_handler)   /* Co-Processor Exception        */
 278         TRAP_ENTRY(0x29, my_trap_handler)   /* Data Access Error             */
 279         TRAP_ENTRY(0x2a, my_trap_handler)   /* Division by zero, you lose... */
 280         TRAP_ENTRY(0x2b, my_trap_handler)   /* Data Store Error              */
 281         TRAP_ENTRY(0x2c, my_trap_handler)   /* Data Access MMU-Miss          */
 282         TRAP_ENTRY(0x2d, my_trap_handler)   /* Undefined...                  */
 283         TRAP_ENTRY(0x2e, my_trap_handler)   /* Undefined...                  */
 284         TRAP_ENTRY(0x2f, my_trap_handler)   /* Undefined...                  */
 285         TRAP_ENTRY(0x30, my_trap_handler)   /* Undefined...                  */
 286         TRAP_ENTRY(0x31, my_trap_handler)   /* Undefined...                  */
 287         TRAP_ENTRY(0x32, my_trap_handler)   /* Undefined...                  */
 288         TRAP_ENTRY(0x33, my_trap_handler)   /* Undefined...                  */
 289         TRAP_ENTRY(0x34, my_trap_handler)   /* Undefined...                  */
 290         TRAP_ENTRY(0x35, my_trap_handler)   /* Undefined...                  */
 291         TRAP_ENTRY(0x36, my_trap_handler)   /* Undefined...                  */
 292         TRAP_ENTRY(0x37, my_trap_handler)   /* Undefined...                  */
 293         TRAP_ENTRY(0x38, my_trap_handler)   /* Undefined...                  */
 294         TRAP_ENTRY(0x39, my_trap_handler)   /* Undefined...                  */
 295         TRAP_ENTRY(0x3a, my_trap_handler)   /* Undefined...                  */
 296         TRAP_ENTRY(0x3b, my_trap_handler)   /* Undefined...                  */
 297         TRAP_ENTRY(0x3c, my_trap_handler)   /* Instruction Access MMU-Miss   */
 298         TRAP_ENTRY(0x3d, my_trap_handler)   /* Undefined...                  */
 299         TRAP_ENTRY(0x3e, my_trap_handler)   /* Undefined...                  */
 300         TRAP_ENTRY(0x3f, my_trap_handler)   /* Undefined...                  */
 301         TRAP_ENTRY(0x40, my_trap_handler)   /* Undefined...                  */
 302         TRAP_ENTRY(0x41, my_trap_handler)   /* Undefined...                  */
 303         TRAP_ENTRY(0x42, my_trap_handler)   /* Undefined...                  */
 304         TRAP_ENTRY(0x43, my_trap_handler)   /* Undefined...                  */
 305         TRAP_ENTRY(0x44, my_trap_handler)   /* Undefined...                  */
 306         TRAP_ENTRY(0x45, my_trap_handler)   /* Undefined...                  */
 307         TRAP_ENTRY(0x46, my_trap_handler)   /* Undefined...                  */
 308         TRAP_ENTRY(0x47, my_trap_handler)   /* Undefined...                  */
 309         TRAP_ENTRY(0x48, my_trap_handler)   /* Undefined...                  */
 310         TRAP_ENTRY(0x49, my_trap_handler)   /* Undefined...                  */
 311         TRAP_ENTRY(0x4a, my_trap_handler)   /* Undefined...                  */
 312         TRAP_ENTRY(0x4b, my_trap_handler)   /* Undefined...                  */
 313         TRAP_ENTRY(0x4c, my_trap_handler)   /* Undefined...                  */
 314         TRAP_ENTRY(0x4d, my_trap_handler)   /* Undefined...                  */
 315         TRAP_ENTRY(0x4e, my_trap_handler)   /* Undefined...                  */
 316         TRAP_ENTRY(0x4f, my_trap_handler)   /* Undefined...                  */
 317         TRAP_ENTRY(0x50, my_trap_handler)   /* Undefined...                  */
 318         TRAP_ENTRY(0x51, my_trap_handler)   /* Undefined...                  */
 319         TRAP_ENTRY(0x52, my_trap_handler)   /* Undefined...                  */
 320         TRAP_ENTRY(0x53, my_trap_handler)   /* Undefined...                  */
 321         TRAP_ENTRY(0x54, my_trap_handler)   /* Undefined...                  */
 322         TRAP_ENTRY(0x55, my_trap_handler)   /* Undefined...                  */
 323         TRAP_ENTRY(0x56, my_trap_handler)   /* Undefined...                  */
 324         TRAP_ENTRY(0x57, my_trap_handler)   /* Undefined...                  */
 325         TRAP_ENTRY(0x58, my_trap_handler)   /* Undefined...                  */
 326         TRAP_ENTRY(0x59, my_trap_handler)   /* Undefined...                  */
 327         TRAP_ENTRY(0x5a, my_trap_handler)   /* Undefined...                  */
 328         TRAP_ENTRY(0x5b, my_trap_handler)   /* Undefined...                  */
 329         TRAP_ENTRY(0x5c, my_trap_handler)   /* Undefined...                  */
 330         TRAP_ENTRY(0x5d, my_trap_handler)   /* Undefined...                  */
 331         TRAP_ENTRY(0x5e, my_trap_handler)   /* Undefined...                  */
 332         TRAP_ENTRY(0x5f, my_trap_handler)   /* Undefined...                  */
 333         TRAP_ENTRY(0x60, my_trap_handler)   /* Impl-Dep Exception            */
 334         TRAP_ENTRY(0x61, my_trap_handler)   /* Impl-Dep Exception            */
 335         TRAP_ENTRY(0x62, my_trap_handler)   /* Impl-Dep Exception            */
 336         TRAP_ENTRY(0x63, my_trap_handler)   /* Impl-Dep Exception            */
 337         TRAP_ENTRY(0x64, my_trap_handler)   /* Impl-Dep Exception            */
 338         TRAP_ENTRY(0x65, my_trap_handler)   /* Impl-Dep Exception            */
 339         TRAP_ENTRY(0x66, my_trap_handler)   /* Impl-Dep Exception            */
 340         TRAP_ENTRY(0x67, my_trap_handler)   /* Impl-Dep Exception            */
 341         TRAP_ENTRY(0x68, my_trap_handler)   /* Impl-Dep Exception            */
 342         TRAP_ENTRY(0x69, my_trap_handler)   /* Impl-Dep Exception            */
 343         TRAP_ENTRY(0x6a, my_trap_handler)   /* Impl-Dep Exception            */
 344         TRAP_ENTRY(0x6b, my_trap_handler)   /* Impl-Dep Exception            */
 345         TRAP_ENTRY(0x6c, my_trap_handler)   /* Impl-Dep Exception            */
 346         TRAP_ENTRY(0x6d, my_trap_handler)   /* Impl-Dep Exception            */
 347         TRAP_ENTRY(0x6e, my_trap_handler)   /* Impl-Dep Exception            */
 348         TRAP_ENTRY(0x6f, my_trap_handler)   /* Impl-Dep Exception            */
 349         TRAP_ENTRY(0x70, my_trap_handler)   /* Impl-Dep Exception            */
 350         TRAP_ENTRY(0x71, my_trap_handler)   /* Impl-Dep Exception            */
 351         TRAP_ENTRY(0x72, my_trap_handler)   /* Impl-Dep Exception            */
 352         TRAP_ENTRY(0x73, my_trap_handler)   /* Impl-Dep Exception            */
 353         TRAP_ENTRY(0x74, my_trap_handler)   /* Impl-Dep Exception            */
 354         TRAP_ENTRY(0x75, my_trap_handler)   /* Impl-Dep Exception            */
 355         TRAP_ENTRY(0x76, my_trap_handler)   /* Impl-Dep Exception            */
 356         TRAP_ENTRY(0x77, my_trap_handler)   /* Impl-Dep Exception            */
 357         TRAP_ENTRY(0x78, my_trap_handler)   /* Impl-Dep Exception            */
 358         TRAP_ENTRY(0x79, my_trap_handler)   /* Impl-Dep Exception            */
 359         TRAP_ENTRY(0x7a, my_trap_handler)   /* Impl-Dep Exception            */
 360         TRAP_ENTRY(0x7b, my_trap_handler)   /* Impl-Dep Exception            */
 361         TRAP_ENTRY(0x7c, my_trap_handler)   /* Impl-Dep Exception            */
 362         TRAP_ENTRY(0x7d, my_trap_handler)   /* Impl-Dep Exception            */
 363         TRAP_ENTRY(0x7e, my_trap_handler)   /* Impl-Dep Exception            */
 364         TRAP_ENTRY(0x7f, my_trap_handler)   /* Impl-Dep Exception            */
 365         TRAP_ENTRY(0x80, my_trap_handler)   /* SunOS System Call             */
 366         TRAP_ENTRY(0x81, my_trap_handler)   /* Software Trap                 */
 367         TRAP_ENTRY(0x82, my_trap_handler)   /* Divide by zero trap XXX       */
 368         TRAP_ENTRY(0x83, my_trap_handler)   /* Flush Windows Trap XXX        */
 369         TRAP_ENTRY(0x84, my_trap_handler)   /* Clean Windows Trap XXX        */
 370         TRAP_ENTRY(0x85, my_trap_handler)   /* Software Trap                 */
 371         TRAP_ENTRY(0x86, my_trap_handler)   /* Fix Unaligned Access Trap XXX */
 372         TRAP_ENTRY(0x87, my_trap_handler)   /* Integer Overflow Trap XXX     */
 373         TRAP_ENTRY(0x88, my_trap_handler)   /* Software Trap                 */
 374         TRAP_ENTRY(0x89, my_trap_handler)   /* NetBSD System Call            */
 375         TRAP_ENTRY(0x8a, my_trap_handler)   /* Software Trap                 */
 376         TRAP_ENTRY(0x8b, my_trap_handler)   /* Software Trap                 */
 377         TRAP_ENTRY(0x8c, my_trap_handler)   /* Software Trap                 */
 378         TRAP_ENTRY(0x8d, my_trap_handler)   /* Software Trap                 */
 379         TRAP_ENTRY(0x8e, my_trap_handler)   /* Software Trap                 */
 380         TRAP_ENTRY(0x8f, my_trap_handler)   /* Software Trap                 */
 381         TRAP_ENTRY(0x90, my_trap_handler)   /* SparcLinux System Call        */
 382         TRAP_ENTRY(0x91, my_trap_handler)   /* Software Trap                 */
 383         TRAP_ENTRY(0x92, my_trap_handler)   /* Software Trap                 */
 384         TRAP_ENTRY(0x93, my_trap_handler)   /* Software Trap                 */
 385         TRAP_ENTRY(0x94, my_trap_handler)   /* Software Trap                 */
 386         TRAP_ENTRY(0x95, my_trap_handler)   /* Software Trap                 */
 387         TRAP_ENTRY(0x96, my_trap_handler)   /* Software Trap                 */
 388         TRAP_ENTRY(0x97, my_trap_handler)   /* Software Trap                 */
 389         TRAP_ENTRY(0x98, my_trap_handler)   /* Software Trap                 */
 390         TRAP_ENTRY(0x99, my_trap_handler)   /* Software Trap                 */
 391         TRAP_ENTRY(0x9a, my_trap_handler)   /* Software Trap                 */
 392         TRAP_ENTRY(0x9b, my_trap_handler)   /* Software Trap                 */
 393         TRAP_ENTRY(0x9c, my_trap_handler)   /* Software Trap                 */
 394         TRAP_ENTRY(0x9d, my_trap_handler)   /* Software Trap                 */
 395         TRAP_ENTRY(0x9e, my_trap_handler)   /* Software Trap                 */
 396         TRAP_ENTRY(0x9f, my_trap_handler)   /* Software Trap                 */
 397         TRAP_ENTRY(0xa0, my_trap_handler)   /* Software Trap                 */
 398         TRAP_ENTRY(0xa1, my_trap_handler)   /* Software Trap                 */
 399         TRAP_ENTRY(0xa2, my_trap_handler)   /* Software Trap                 */
 400         TRAP_ENTRY(0xa3, my_trap_handler)   /* Software Trap                 */
 401         TRAP_ENTRY(0xa4, my_trap_handler)   /* Software Trap                 */
 402         TRAP_ENTRY(0xa5, my_trap_handler)   /* Software Trap                 */
 403         TRAP_ENTRY(0xa6, my_trap_handler)   /* Software Trap                 */
 404         TRAP_ENTRY(0xa7, my_trap_handler)   /* Software Trap                 */
 405         TRAP_ENTRY(0xa8, my_trap_handler)   /* Software Trap                 */
 406         TRAP_ENTRY(0xa9, my_trap_handler)   /* Software Trap                 */
 407         TRAP_ENTRY(0xaa, my_trap_handler)   /* Software Trap                 */
 408         TRAP_ENTRY(0xab, my_trap_handler)   /* Software Trap                 */
 409         TRAP_ENTRY(0xac, my_trap_handler)   /* Software Trap                 */
 410         TRAP_ENTRY(0xad, my_trap_handler)   /* Software Trap                 */
 411         TRAP_ENTRY(0xae, my_trap_handler)   /* Software Trap                 */
 412         TRAP_ENTRY(0xaf, my_trap_handler)   /* Software Trap                 */
 413         TRAP_ENTRY(0xb0, my_trap_handler)   /* Software Trap                 */
 414         TRAP_ENTRY(0xb1, my_trap_handler)   /* Software Trap                 */
 415         TRAP_ENTRY(0xb2, my_trap_handler)   /* Software Trap                 */
 416         TRAP_ENTRY(0xb3, my_trap_handler)   /* Software Trap                 */
 417         TRAP_ENTRY(0xb4, my_trap_handler)   /* Software Trap                 */
 418         TRAP_ENTRY(0xb5, my_trap_handler)   /* Software Trap                 */
 419         TRAP_ENTRY(0xb6, my_trap_handler)   /* Software Trap                 */
 420         TRAP_ENTRY(0xb7, my_trap_handler)   /* Software Trap                 */
 421         TRAP_ENTRY(0xb8, my_trap_handler)   /* Software Trap                 */
 422         TRAP_ENTRY(0xb9, my_trap_handler)   /* Software Trap                 */
 423         TRAP_ENTRY(0xba, my_trap_handler)   /* Software Trap                 */
 424         TRAP_ENTRY(0xbb, my_trap_handler)   /* Software Trap                 */
 425         TRAP_ENTRY(0xbc, my_trap_handler)   /* Software Trap                 */
 426         TRAP_ENTRY(0xbd, my_trap_handler)   /* Software Trap                 */
 427         TRAP_ENTRY(0xbe, my_trap_handler)   /* Software Trap                 */
 428         TRAP_ENTRY(0xbf, my_trap_handler)   /* Software Trap                 */
 429         TRAP_ENTRY(0xc0, my_trap_handler)   /* Software Trap                 */
 430         TRAP_ENTRY(0xc1, my_trap_handler)   /* Software Trap                 */
 431         TRAP_ENTRY(0xc2, my_trap_handler)   /* Software Trap                 */
 432         TRAP_ENTRY(0xc3, my_trap_handler)   /* Software Trap                 */
 433         TRAP_ENTRY(0xc4, my_trap_handler)   /* Software Trap                 */
 434         TRAP_ENTRY(0xc5, my_trap_handler)   /* Software Trap                 */
 435         TRAP_ENTRY(0xc6, my_trap_handler)   /* Software Trap                 */
 436         TRAP_ENTRY(0xc7, my_trap_handler)   /* Software Trap                 */
 437         TRAP_ENTRY(0xc8, my_trap_handler)   /* Software Trap                 */
 438         TRAP_ENTRY(0xc9, my_trap_handler)   /* Software Trap                 */
 439         TRAP_ENTRY(0xca, my_trap_handler)   /* Software Trap                 */
 440         TRAP_ENTRY(0xcb, my_trap_handler)   /* Software Trap                 */
 441         TRAP_ENTRY(0xcc, my_trap_handler)   /* Software Trap                 */
 442         TRAP_ENTRY(0xcd, my_trap_handler)   /* Software Trap                 */
 443         TRAP_ENTRY(0xce, my_trap_handler)   /* Software Trap                 */
 444         TRAP_ENTRY(0xcf, my_trap_handler)   /* Software Trap                 */
 445         TRAP_ENTRY(0xd0, my_trap_handler)   /* Software Trap                 */
 446         TRAP_ENTRY(0xd1, my_trap_handler)   /* Software Trap                 */
 447         TRAP_ENTRY(0xd2, my_trap_handler)   /* Software Trap                 */
 448         TRAP_ENTRY(0xd3, my_trap_handler)   /* Software Trap                 */
 449         TRAP_ENTRY(0xd4, my_trap_handler)   /* Software Trap                 */
 450         TRAP_ENTRY(0xd5, my_trap_handler)   /* Software Trap                 */
 451         TRAP_ENTRY(0xd6, my_trap_handler)   /* Software Trap                 */
 452         TRAP_ENTRY(0xd7, my_trap_handler)   /* Software Trap                 */
 453         TRAP_ENTRY(0xd8, my_trap_handler)   /* Software Trap                 */
 454         TRAP_ENTRY(0xd9, my_trap_handler)   /* Software Trap                 */
 455         TRAP_ENTRY(0xda, my_trap_handler)   /* Software Trap                 */
 456         TRAP_ENTRY(0xdb, my_trap_handler)   /* Software Trap                 */
 457         TRAP_ENTRY(0xdc, my_trap_handler)   /* Software Trap                 */
 458         TRAP_ENTRY(0xdd, my_trap_handler)   /* Software Trap                 */
 459         TRAP_ENTRY(0xde, my_trap_handler)   /* Software Trap                 */
 460         TRAP_ENTRY(0xdf, my_trap_handler)   /* Software Trap                 */
 461         TRAP_ENTRY(0xe0, my_trap_handler)   /* Software Trap                 */
 462         TRAP_ENTRY(0xe1, my_trap_handler)   /* Software Trap                 */
 463         TRAP_ENTRY(0xe2, my_trap_handler)   /* Software Trap                 */
 464         TRAP_ENTRY(0xe3, my_trap_handler)   /* Software Trap                 */
 465         TRAP_ENTRY(0xe4, my_trap_handler)   /* Software Trap                 */
 466         TRAP_ENTRY(0xe5, my_trap_handler)   /* Software Trap                 */
 467         TRAP_ENTRY(0xe6, my_trap_handler)   /* Software Trap                 */
 468         TRAP_ENTRY(0xe7, my_trap_handler)   /* Software Trap                 */
 469         TRAP_ENTRY(0xe8, my_trap_handler)   /* Software Trap                 */
 470         TRAP_ENTRY(0xe9, my_trap_handler)   /* Software Trap                 */
 471         TRAP_ENTRY(0xea, my_trap_handler)   /* Software Trap                 */
 472         TRAP_ENTRY(0xeb, my_trap_handler)   /* Software Trap                 */
 473         TRAP_ENTRY(0xec, my_trap_handler)   /* Software Trap                 */
 474         TRAP_ENTRY(0xed, my_trap_handler)   /* Software Trap                 */
 475         TRAP_ENTRY(0xee, my_trap_handler)   /* Software Trap                 */
 476         TRAP_ENTRY(0xef, my_trap_handler)   /* Software Trap                 */
 477         TRAP_ENTRY(0xf0, my_trap_handler)   /* Software Trap                 */
 478         TRAP_ENTRY(0xf1, my_trap_handler)   /* Software Trap                 */
 479         TRAP_ENTRY(0xf2, my_trap_handler)   /* Software Trap                 */
 480         TRAP_ENTRY(0xf3, my_trap_handler)   /* Software Trap                 */
 481         TRAP_ENTRY(0xf4, my_trap_handler)   /* Software Trap                 */
 482         TRAP_ENTRY(0xf5, my_trap_handler)   /* Software Trap                 */
 483         TRAP_ENTRY(0xf6, my_trap_handler)   /* Software Trap                 */
 484         TRAP_ENTRY(0xf7, my_trap_handler)   /* Software Trap                 */
 485         TRAP_ENTRY(0xf8, my_trap_handler)   /* Software Trap                 */
 486         TRAP_ENTRY(0xf9, my_trap_handler)   /* Software Trap                 */
 487         TRAP_ENTRY(0xfa, my_trap_handler)   /* Software Trap                 */
 488         TRAP_ENTRY(0xfb, my_trap_handler)   /* Software Trap                 */
 489         TRAP_ENTRY(0xfc, my_trap_handler)   /* Software Trap                 */
 490         TRAP_ENTRY(0xfd, my_trap_handler)   /* Software Trap                 */
 491         TRAP_ENTRY(0xfe, my_trap_handler)   /* Software Trap                 */
 492         TRAP_ENTRY(0xff, my_trap_handler)   /* Software Trap                 */ 
 493 
 494         .skip 4096
 495 
 496 C_LABEL(msgbufmapped):
 497         .word   1
 498 
 499 
 500 
 501 /* Cool, here we go. Pick up the romvec pointer in %o0 and stash it in
 502    %g7 and at _prom_vector_p. And also quickly check whether we are on
 503    a v0 or v2 prom.
 504 */
 505 
 506 gokernel:       or      %g0, %o0, %g7
 507                 sethi   %hi( C_LABEL(prom_vector_p) ), %g1
 508                 st      %o0, [%g1 + %lo( C_LABEL(prom_vector_p) )]   ! we will need it later
 509                 rd      %psr, %l2
 510                 rd      %wim, %l3
 511                 rd      %tbr, %l4
 512                 or      %g0, %o2, %l5           ! could be prom magic value...
 513         
 514 #if 0 /* You think I'm nutz? */
 515                 subcc   %l5, 0x0, %g0           ! check for magic SMP pointer
 516                 bne     nosmp   
 517                 nop
 518                 call    %o2                     ! call smp prom setup 
 519                 nop
 520 #endif /* I will be soon... */
 521 
 522 /* Acquire boot time privileged register values, this will help debugging.
 523  * I figure out and store nwindows later on.
 524  */
 525 
 526 nosmp:          sethi   %hi( C_LABEL(boot_psr) ), %l1
 527                 st      %l2, [%l1 + %lo( C_LABEL(boot_psr) )]
 528                 sethi   %hi( C_LABEL(boot_wim) ), %l1
 529                 st      %l3, [%l1 + %lo( C_LABEL(boot_wim) )]
 530                 sethi   %hi( C_LABEL(boot_tbr) ), %l1
 531                 st      %l4, [%l1 + %lo( C_LABEL(boot_tbr) )]
 532                 sethi   %hi( C_LABEL(boot_smp_ptr) ), %l1
 533                 st      %l5, [%l1 + %lo( C_LABEL(boot_smp_ptr) )]
 534 
 535                 or      %g0, %o0, %g7
 536                 sethi   %hi( C_LABEL(prom_vector_p) ), %g5
 537                 st      %o0, [%g5 + %lo( C_LABEL(prom_vector_p) )]   ! we will need it later
 538 
 539                 ld      [%g7 + 0x4], %o3
 540                 subcc   %o3, 0x2, %g0                   ! a v2 prom?
 541                 be      found_v2
 542                 nop
 543 
 544 /* Old sun4's pass our load address into %o0 instead of the prom
 545    pointer. On sun4's you have to hard code the romvec pointer into
 546    your code. Sun probably still does that because they don't even
 547    trust their own "OpenBoot" specifications.
 548 */
 549 
 550                 sethi   %hi(LOAD_ADDR), %g6
 551                 subcc   %o0, %g6, %g0           ! an old sun4?
 552                 be      no_sun4_here
 553                 nop
 554 
 555                 sethi   %hi( C_LABEL(prom_iface_vers) ), %g1
 556                 st      %g0, [%g1 + %lo( C_LABEL(prom_iface_vers) )]
 557                 b       not_v2
 558                 nop
 559 
 560 found_v2:
 561                 or      %g0, 0x2, %o5
 562                 sethi   %hi( C_LABEL(prom_iface_vers) ), %g1
 563                 st      %o5, [%g1 + %lo( C_LABEL(prom_iface_vers) )]
 564 
 565 not_v2:
 566 
 567 /* Get the machine type via the mysterious romvec node operations.
 568  * Here we can find out whether we are on a sun4 sun4c, sun4m, or
 569  * a sun4m. The "nodes" are set up as a bunch of n-ary trees which
 570  * you can traverse to get information about devices and such. The
 571  * information acquisition happens via the node-ops which are defined
 572  * in the linux_openprom.h header file. Of particular interest is the
 573  * 'nextnode(int node)' function as it does the smart thing when
 574  * presented with a value of '0', it gives you the first node in the
 575  * tree. These node integers probably offset into some internal prom
 576  * pointer table the openboot has. It's completely undocumented, so
 577  * I'm not about to go sifting through the prom address space, but may
 578  * do so if I get suspicious enough. :-)
 579  */
 580 
 581                 or      %g0, %g7, %l1
 582                 add     %l1, 0x1c, %l1          
 583                 ld      [%l1], %l0
 584                 ld      [%l0], %l0
 585                 call    %l0
 586                 or      %g0, %g0, %o0           ! next_node(0) = first_node
 587 
 588                 sethi   %hi( C_LABEL(cputypvar) ), %o1  ! first node has cpu-arch
 589                 or      %o1, %lo( C_LABEL(cputypvar) ), %o1
 590                 sethi   %hi( C_LABEL(cputypval) ), %o2  ! information, the string
 591                 or      %o2, %lo( C_LABEL(cputypval) ), %o2
 592                 ld      [%l1], %l0              ! 'compatibility' tells
 593                 ld      [%l0 + 0xc], %l0        ! that we want 'sun4x' where
 594                 call    %l0                     ! x is one of '', 'c', 'm',
 595                 nop                             ! 'd' or 'e'. %o2 holds pointer
 596                                                 ! to a buf where above string
 597                                                 ! will get stored by the prom.
 598 
 599                 sethi   %hi( C_LABEL(cputypval) ), %o2  ! better safe than sorry
 600                 or      %o2, %lo( C_LABEL(cputypval) ), %o2
 601                 ldub    [%o2 + 0x4], %o0
 602                 subcc   %o0, 'c', %g0           ! we already know we are not
 603                 be      is_sun4c                ! on a plain sun4 because of
 604                 nop                             ! the check for 0x4000 in %o0
 605                 subcc   %o0, 'm', %g0           ! at start:
 606                 be      is_sun4m
 607                 nop
 608                 b       no_sun4d_here           ! god bless the person who
 609                 nop                             ! tried to run this on sun4d
 610 
 611 is_sun4m:
 612 is_sun4c:                                       ! OK, this is a sun4c, yippie
 613                 or      %g0, %g7, %g6           ! load up the promvec offsets
 614                 sethi   %hi(prom_magic), %g5    ! magic mushroom :>
 615                 st      %g6, [%g5 + %lo(prom_magic)]
 616                 add     %g7, 0x4, %g6
 617                 sethi   %hi(prom_rom_vers), %g5
 618                 st      %g6, [%g5 + %lo(prom_rom_vers)]
 619                 add     %g7, 0x8, %g6
 620                 sethi   %hi(prom_pluginvers), %g5
 621                 st      %g6, [%g5 + %lo(prom_pluginvers)]
 622                 add     %g7, 0xc, %g6
 623                 sethi   %hi(prom_revision), %g5
 624                 st      %g6, [%g5 + %lo(prom_revision)]
 625                 add     %g7, 0x10, %g6
 626                 sethi   %hi(prom_v0mem_desc), %g5
 627                 st      %g6, [%g5 + %lo(prom_v0mem_desc)]
 628                 add     %g7, 0x1c, %g6
 629                 sethi   %hi(prom_nodefuncs), %g5
 630                 st      %g6, [%g5 + %lo(prom_nodefuncs)]
 631                 add     %g7, 0x68, %g6
 632                 sethi   %hi(prom_printf), %g5
 633                 st      %g6, [%g5 + %lo(prom_printf)]
 634                 add     %g7, 0x6c, %g6
 635                 sethi   %hi(prom_abort), %g5
 636                 st      %g6, [%g5 + %lo(prom_abort)]
 637                 add     %g7, 0x74, %g6
 638                 sethi   %hi(prom_halt), %g5
 639                 st      %g6, [%g5 + %lo(prom_halt)]
 640                 add     %g7, 0x78, %g6
 641                 sethi   %hi(prom_sync), %g5
 642                 st      %g6, [%g5 + %lo(prom_sync)]
 643                 add     %g7, 0x7c, %g6
 644                 sethi   %hi(prom_eval), %g5
 645                 st      %g6, [%g5 + %lo(prom_eval)]
 646                 add     %g7, 0x80, %g6
 647                 sethi   %hi(prom_v0bootline), %g6
 648                 st      %g6, [%g5 + %lo(prom_v0bootline)]
 649 
 650 
 651 /* That was easy, now lets try to print some message on the screen.
 652  * We don't have to worry about bad address translations when the prom
 653  * addresses our pointers because our pointers are at 0x0-kern_size
 654  * as the prom expects.
 655  */
 656 
 657                 sethi   %hi(boot_msg), %o0      
 658                 or      %o0, %lo(boot_msg), %o0
 659                 sethi   %hi(prom_printf), %o1
 660                 ld      [%o1 + %lo(prom_printf)], %o1
 661                 ld      [%o1], %o1
 662                 call    %o1                     ! print boot message #1
 663                 nop
 664 
 665                 sethi   %hi(pstring1), %o0
 666                 or      %o0, %lo(pstring1), %o0
 667                 sethi   %hi(prom_printf), %o2
 668                 ld      [%o2 + %lo(prom_printf)], %o2
 669                 ld      [%o2], %o2
 670                 sethi   %hi(prom_magic), %o1
 671                 ld      [%o1 + %lo(prom_magic)], %o1
 672                 ld      [%o1], %o1
 673                 call    %o2
 674                 nop
 675 
 676                 sethi   %hi(pstring2), %o0
 677                 or      %o0, %lo(pstring2), %o0
 678                 sethi   %hi(prom_printf), %o2
 679                 ld      [%o2 + %lo(prom_printf)], %o2
 680                 ld      [%o2], %o2
 681                 sethi   %hi( C_LABEL(prom_iface_vers) ), %o1
 682                 ld      [%o1 + %lo( C_LABEL(prom_iface_vers) )], %o1
 683                 ld      [%o1], %o1
 684                 call    %o2
 685                 nop
 686 
 687                 b       rest_of_boot
 688                 nop
 689 
 690 no_sun4_here:
 691                 ld      [%g7 + 0x68], %o1
 692                 set     sun4_notsup, %o0
 693                 call    %o1
 694                 nop
 695 
 696 rest_of_boot:
 697                 or      %g0, PAGE_SHIFT, %g5
 698 
 699                 sethi   %hi(AC_CONTEXT), %g1    ! kernel context, safe now
 700                                                 ! the only valid context
 701                                                 ! until we call paging_init()
 702                 stba    %g0, [%g1] ASI_CONTROL
 703 
 704 
 705 /* I make the kernel image sit in memory relative to 0x0 with the text 
 706  * starting at 0x4000. Now it looks like the way memory is set in Linux
 707  * on an ix86.
 708  */
 709 
 710 /* Uh, oh, interrupt time. This crap is real confusing. What I want to do is
 711  * clear all interrupts, map the interrupt enable register which in effect
 712  * enables non-maskable interrupts (or NMI's). Actually we take no interrupts
 713  * until we frob with the %tbr (trap base register) which the prom has set 
 714  * to all its routines which allows some sanity during bootup.
 715  */
 716 
 717                 sethi   %hi(IE_reg_addr), %l0
 718                 or      %l0, %lo(IE_reg_addr), %l0
 719 
 720                 set     0xf4000000, %l3
 721                 sethi   %hi(INT_ENABLE_REG_PHYSADR), %l2
 722                 or      %l2, %lo(INT_ENABLE_REG_PHYSADR), %l2
 723                 srl     %l2, %g5, %l2
 724                 or      %l2, %l3, %l1           
 725 
 726                 sta     %l1, [%l0] ASI_PTE
 727         
 728                 or      %g0, INTS_ENAB, %l1
 729                 nop
 730                 nop
 731 
 732                 stb     %l1, [%l0]
 733         
 734 
 735 /* Aieee, now set PC and nPC, enable traps, give ourselves a stack and it's
 736  * show-time!
 737  */
 738 
 739                 sethi   %hi(1f), %g1
 740                 or      %g1, %lo(1f), %g1
 741                 jmp     %g1
 742                 nop
 743 
 744                 .align 4
 745 1:              sethi   %hi( C_LABEL(cputyp) ), %o0
 746                 st      %g4, [%o0 + %lo( C_LABEL(cputyp) )]
 747 
 748                 sethi   %hi( C_LABEL(pgshift) ), %o0
 749                 st      %g5, [%o0 + %lo( C_LABEL(pgshift) )]
 750 
 751                 mov     1, %o0
 752                 sll     %o0, %g5, %g5
 753                 sethi   %hi( C_LABEL(nbpg) ), %o0
 754                 st      %g5, [%o0 + %lo( C_LABEL(nbpg) )]
 755 
 756                 sub     %g5, 1, %g5
 757                 sethi   %hi( C_LABEL(pgofset) ), %o0
 758                 st      %g5, [%o0 + %lo( C_LABEL(pgofset) )]
 759 
 760 
 761                 rd      %psr, %g3
 762                 andn    %g3, PSR_ET, %g3
 763                 wr      %g3, 0x0, %psr          ! make sure traps are off
 764                                                 ! before we play around
 765                 WRITE_PAUSE                     ! no guarantees until 3 insns
 766 
 767 
 768                 wr      %g0, 0x0, %wim          ! magical invalid window reg
 769                 WRITE_PAUSE                     ! see above
 770 
 771 /* I keep the timer interrupt on so that BogoMIPS works and the prom
 772  * keeps updating it's "jiffies" counter. 100HZ clock on sparcstations.
 773  */     
 774 
 775 /* If gas wasn't so dumb, I could use or'd macros in this next
 776  * write. ;-( like this (PSR_PS | PSR_S | PSR_PIL)...
 777  */
 778 
 779                 sethi   %hi(PSR_PS | PSR_S | PSR_PIL | PSR_EF), %g2
 780                 or      %g2, %lo(PSR_PS | PSR_S | PSR_PIL | PSR_EF), %g2
 781                 wr      %g2, 0x0, %psr
 782                 WRITE_PAUSE
 783 
 784                 wr      %g0, 0x2, %wim          ! window 1 invalid
 785                 WRITE_PAUSE
 786 
 787                 or      %g0, 0x1, %g1
 788                 sethi   %hi( C_LABEL(current) + THREAD_WIM), %g2
 789                 st      %g1, [%g2 + %lo( C_LABEL(current) + THREAD_WIM)]
 790 
 791 /* I want a kernel stack NOW! */
 792 
 793                 set     ( C_LABEL(init_user_stack) + 4092 - 96 - 80), %fp       
 794                 set     ( C_LABEL(init_user_stack) + 4092), %sp
 795 
 796 /* now out stack is set up similarly to the way it is on the i386 */
 797 
 798                 rd      %psr, %l0
 799                 wr      %l0, PSR_ET, %psr
 800                 WRITE_PAUSE
 801 
 802 /*
 803  * Maybe the prom zeroes out our BSS section, maybe it doesn't. I certainly 
 804  * don't know, do you?
 805  */
 806 
 807                 set     C_LABEL(edata) , %o0
 808                 set     C_LABEL(end) , %o1
 809                 sub     %o1, %o0, %g2
 810                 sethi   %hi( C_LABEL(kernel_bss_len) ), %g3
 811                 st      %g2, [%g3 + %lo( C_LABEL(kernel_bss_len) )]
 812                 sethi   %hi( C_LABEL(trapbase) ), %g3
 813                 or      %g3, %lo( C_LABEL(trapbase) ), %g3
 814                 sethi   %hi( C_LABEL(etext) ), %g4
 815                 or      %g4, %lo( C_LABEL(etext) ), %g4                 
 816                 sub     %g4, %g3, %g2
 817                 sethi   %hi( C_LABEL(kernel_text_len) ), %g3
 818                 st      %g2, [%g3 + %lo( C_LABEL(kernel_text_len) )]
 819                 sethi   %hi( C_LABEL(etext) ), %g4
 820                 or      %g4, %lo( C_LABEL(etext) ), %g4
 821                 sethi   %hi( C_LABEL(edata) ), %g3
 822                 or      %g3, %lo( C_LABEL(edata) ), %g3
 823                 sub     %g3, %g4, %g2
 824                 sethi   %hi( C_LABEL(kernel_data_len) ), %g3
 825                 st      %g2, [%g3 + %lo( C_LABEL(kernel_data_len) )]
 826                 or      %g0, %g0, %g1
 827 
 828 1:      
 829                 st      %g0, [%o0]
 830                 add     %o0, 0x4, %o0
 831                 subcc   %o0, %o1, %g0
 832                 bl      1b
 833                 nop
 834 
 835 /* Compute NWINDOWS and stash it away. Now uses %wim trick explained
 836  * in the V8 manual. Ok, this method seems to work, sparc is cool...
 837  */
 838 
 839                 sethi   %hi(0xffffffff), %g1
 840                 rd      %wim, %g2                       ! save current value
 841                 or      %g1, %lo(0xffffffff), %g1
 842                 wr      %g1, 0x0, %wim
 843                 rd      %wim, %g1                       ! get remaining mask
 844                 wr      %g2, 0x0, %wim                  ! restore old value
 845                 WRITE_PAUSE
 846 
 847                 or      %g0, 0x0, %g3
 848 
 849 1:              srl     %g1, 0x1, %g1                   ! shift until highest
 850                 subcc   %g1, 0x0, %g0                   ! bit set
 851                 bne     1b
 852                 add     %g3, 0x1, %g3
 853                 sethi   %hi( C_LABEL(nwindows) ), %g4
 854                 st      %g3, [%g4 + %lo( C_LABEL(nwindows) )]   ! store final value
 855                 sub     %g3, 0x1, %g3
 856                 sethi   %hi( C_LABEL(nwindowsm1) ), %g4
 857                 st      %g3, [%g4 + %lo( C_LABEL(nwindowsm1) )]
 858 
 859 
 860 /* Here we go */
 861 
 862                 set     C_LABEL(trapbase), %g3
 863                 wr      %g3, 0x0, %tbr
 864                 WRITE_PAUSE
 865 
 866 
 867 /* First we call init_prom() to set up romvec, then off to start_kernel() */
 868 /* XXX put this in arch_init() */
 869 
 870                 sethi   %hi( C_LABEL(prom_vector_p) ), %g5
 871                 call    C_LABEL(init_prom)
 872                 ld      [%g5 + %lo( C_LABEL(prom_vector_p) )], %o0   /* delay slot */
 873 
 874                 call    C_LABEL(start_kernel)
 875                 nop
 876         
 877                 call    halt_me
 878                 nop
 879 
 880 /* There, happy now adrian? */
 881 
 882 no_sun4d_here:
 883                 ld      [%g7 + 0x68], %o1
 884                 set     sun4d_notsup, %o0
 885                 call    %o1
 886                 nop
 887                 b       halt_me
 888                 nop
 889 
 890 halt_me:
 891                 ld      [%g7 + 0x74], %o0
 892                 call    %o0                     ! get us out of here...
 893                 nop                             ! apparently solaris is better
 894 
 895         .data
 896         .align 4
 897 
 898 /*
 899  * Fill up the prom vector, note in particular the kind first element,
 900  * no joke. I don't need all of them in here as the entire prom vector
 901  * gets initialized in c-code so all routines can use it.
 902  */
 903 
 904                         .globl C_LABEL(prom_vector_p)
 905 
 906 C_LABEL(prom_vector_p): .skip 4
 907 prom_magic:             .skip 4                 ! magic mushroom, beware...
 908 prom_rom_vers:          .skip 4                 ! interface version (v0 or v2)
 909 prom_pluginvers:        .skip 4                 ! XXX help help help ???
 910 prom_revision:          .skip 4                 ! PROM revision (ie. 1.4)
 911 prom_halt:              .skip 4                 ! void halt(void)  solaris friend
 912 prom_eval:              .skip 4                 ! void eval(int len, char* string)
 913 prom_v0bootline:        .skip 4                 ! boot command line
 914 prom_v0mem_desc:        .skip 4                 ! V0 memory descriptor list ptr.
 915 prom_nodefuncs:         .skip 4                 ! Magical Node functions
 916 prom_printf:            .skip 4                 ! minimal printf()
 917 
 918 /* The prom_abort pointer MUST be mapped in all contexts, because if you
 919  * don't then if a user process is running when you press the abort key
 920  * sequence, all sorts of bad things can happen
 921  */
 922 
 923 prom_abort:             .skip 4         ! L1-A magic cookie
 924                                         ! must be mapped in ALL contexts
 925 
 926 /* prom_sync is a place where the kernel should place a pointer to a kernel
 927  * function that when called will sync all pending information to the drives
 928  * and then promptly return. If the kernel gets aborted with 'L1-A' one can
 929  * give the 'sync' command to the boot prompt and this magic cookie gets
 930  * executed. Nice feature eh?
 931  */
 932 
 933 prom_sync:              .skip 4                 ! hook in prom for sync func
 934 
 935         .align 4
 936 
 937 /* We calculate the following at boot time, window fills/spills and trap entry
 938  * code uses these to keep track of the register windows.
 939  */
 940 
 941         .globl C_LABEL(nwindows)
 942         .globl C_LABEL(nwindowsm1)
 943 C_LABEL(nwindows):      .skip 4
 944 C_LABEL(nwindowsm1):    .skip 4
 945 
 946         .align 4
 947 /* Boot time privileged register values, plus magic %o2 value */
 948 
 949         .globl C_LABEL(boot_wim)
 950         .globl C_LABEL(boot_psr)
 951         .globl C_LABEL(boot_tbr)
 952         .globl C_LABEL(boot_smp_ptr)
 953 C_LABEL(boot_wim):              .skip 4
 954 C_LABEL(boot_psr):              .skip 4
 955 C_LABEL(boot_tbr):              .skip 4
 956 C_LABEL(boot_smp_ptr):          .skip 4
 957 
 958 
 959         .align 4
 960 /* Miscellaneous pieces of information saved at kernel startup. */
 961         .globl C_LABEL(kernel_text_len)
 962         .globl C_LABEL(kernel_data_len)
 963         .globl C_LABEL(kernel_bss_len)
 964 C_LABEL(kernel_text_len):       .word 0
 965 C_LABEL(kernel_data_len):       .word 0
 966 C_LABEL(kernel_bss_len):        .word 0
 967 
 968 /* These are for page alignment/offset information as they change from
 969    machine to machine.
 970 */
 971 
 972         .globl  C_LABEL(pgshift)
 973         .globl  C_LABEL(nbpg)
 974         .globl  C_LABEL(pgofset)
 975 
 976         .align 4
 977 C_LABEL(pgshift):
 978         .word   1
 979 C_LABEL(nbpg):
 980         .word   1
 981 C_LABEL(pgofset):
 982         .word   1
 983 
 984 /* Just to get the kernel through the compiler for now */
 985         .globl C_LABEL(swapper_pg_dir), C_LABEL(pg0)
 986         .globl C_LABEL(empty_bad_page)
 987         .globl C_LABEL(empty_bad_page_table)
 988         .globl C_LABEL(empty_zero_page)
 989         .globl C_LABEL(floppy_track_buffer)
 990 C_LABEL(floppy_track_buffer):
 991         .fill 512*2*36,1,0
 992 
 993         .align 4
 994 C_LABEL(swapper_pg_dir):                .skip 0x1000
 995 C_LABEL(pg0):                           .skip 0x1000
 996 C_LABEL(empty_bad_page):                .skip 0x1000
 997 C_LABEL(empty_bad_page_table):          .skip 0x1000
 998 C_LABEL(empty_zero_page):               .skip 0x1000
 999 
1000                 .align 4
1001 diagstr:        .asciz  "DIAG\n"
1002                 .align 4
/* */
root/arch/sparc/kernel/head.S
