/* SPDX-License-Identifier: GPL-2.0 */
/*
* head.S: The initial boot code for the Sparc port of Linux.
*
* Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
* Copyright (C) 1995,1999 Pete Zaitcev (zaitcev@yahoo.com)
* Copyright (C) 1996 Miguel de Icaza (miguel@nuclecu.unam.mx)
* Copyright (C) 1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
* Copyright (C) 1997 Michael A. Griffith (grif@acm.org)
*
* CompactPCI platform by Eric Brower, 1999.
*/
#include <linux/export.h>
#include <linux/version.h>
#include <linux/init.h>
#include <asm/head.h>
#include <asm/asi.h>
#include <asm/contregs.h>
#include <asm/ptrace.h>
#include <asm/psr.h>
#include <asm/page.h>
#include <asm/kdebug.h>
#include <asm/winmacro.h>
#include <asm/thread_info.h> /* TI_UWINMASK */
#include <asm/errno.h>
#include <asm/pgtable.h> /* PGDIR_SHIFT */
.data
/* The following are used with the prom_vector node-ops to figure out
* the cpu-type
*/
.align 4
.globl cputypval
cputypval:
.asciz "sun4m"
.ascii " "
/* Tested on SS-5, SS-10 */
.align 4
cputypvar:
.asciz "compatible"
.align 4
notsup:
.asciz "Sparc-Linux sun4/sun4c or MMU-less not supported\n\n"
.align 4
sun4e_notsup:
.asciz "Sparc-Linux sun4e support does not exist\n\n"
.align 4
/* The trap-table - located in the __HEAD section */
#include "ttable_32.S"
.align PAGE_SIZE
/* This was the only reasonable way I could think of to properly align
* these page-table data structures.
*/
.globl empty_zero_page
empty_zero_page: .skip PAGE_SIZE
EXPORT_SYMBOL(empty_zero_page)
.global root_flags
.global ram_flags
.global root_dev
.global sparc_ramdisk_image
.global sparc_ramdisk_size
/* This stuff has to be in sync with SILO and other potential boot loaders
* Fields should be kept upward compatible and whenever any change is made,
* HdrS version should be incremented.
*/
.ascii "HdrS"
.word LINUX_VERSION_CODE
.half 0x0203 /* HdrS version */
root_flags:
.half 1
root_dev:
.half 0
ram_flags:
.half 0
sparc_ramdisk_image:
.word 0
sparc_ramdisk_size:
.word 0
.word reboot_command
.word 0, 0, 0
.word _end
/* Cool, here we go. Pick up the romvec pointer in %o0 and stash it in
* %g7 and at prom_vector_p. And also quickly check whether we are on
* a v0, v2, or v3 prom.
*/
gokernel:
/* Ok, it's nice to know, as early as possible, if we
* are already mapped where we expect to be in virtual
* memory. The Solaris /boot elf format bootloader
* will peek into our elf header and load us where
* we want to be, otherwise we have to re-map.
*
* Some boot loaders don't place the jmp'rs address
* in %o7, so we do a pc-relative call to a local
* label, then see what %o7 has.
*/
mov %o7, %g4 ! Save %o7
/* Jump to it, and pray... */
current_pc:
call 1f
nop
1:
mov %o7, %g3
tst %o0
be no_sun4u_here
mov %g4, %o7 /* Previous %o7. */
mov %o0, %l0 ! stash away romvec
mov %o0, %g7 ! put it here too
mov %o1, %l1 ! stash away debug_vec too
/* Ok, let's check out our run time program counter. */
set current_pc, %g5
cmp %g3, %g5
be already_mapped
nop
/* %l6 will hold the offset we have to subtract
* from absolute symbols in order to access areas
* in our own image. If already mapped this is
* just plain zero, else it is KERNBASE.
*/
set KERNBASE, %l6
b copy_prom_lvl14
nop
already_mapped:
mov 0, %l6
/* Copy over the Prom's level 14 clock handler. */
copy_prom_lvl14:
#if 1
/* DJHR
* preserve our linked/calculated instructions
*/
set lvl14_save, %g1
set t_irq14, %g3
sub %g1, %l6, %g1 ! translate to physical
sub %g3, %l6, %g3 ! translate to physical
ldd [%g3], %g4
std %g4, [%g1]
ldd [%g3+8], %g4
std %g4, [%g1+8]
#endif
rd %tbr, %g1
andn %g1, 0xfff, %g1 ! proms trap table base
or %g0, (0x1e<<4), %g2 ! offset to lvl14 intr
or %g1, %g2, %g2
set t_irq14, %g3
sub %g3, %l6, %g3
ldd [%g2], %g4
std %g4, [%g3]
ldd [%g2 + 0x8], %g4
std %g4, [%g3 + 0x8] ! Copy proms handler
/* DON'T TOUCH %l0 thru %l5 in these remapping routines,
* we need their values afterwards!
*/
/* Now check whether we are already mapped, if we
* are we can skip all this garbage coming up.
*/
copy_prom_done:
cmp %l6, 0
be go_to_highmem ! this will be a nop then
nop
/* Validate that we are in fact running on an
* SRMMU based cpu.
*/
set 0x4000, %g6
cmp %g7, %g6
bne not_a_sun4
nop
halt_notsup:
ld [%g7 + 0x68], %o1
set notsup, %o0
sub %o0, %l6, %o0
call %o1
nop
ba halt_me
nop
not_a_sun4:
/* It looks like this is a machine we support.
* Now find out what MMU we are dealing with
* LEON - identified by the psr.impl field
* Viking - identified by the psr.impl field
* In all other cases a sun4m srmmu.
* We check that the MMU is enabled in all cases.
*/
/* Check if this is a LEON CPU */
rd %psr, %g3
srl %g3, PSR_IMPL_SHIFT, %g3
and %g3, PSR_IMPL_SHIFTED_MASK, %g3
cmp %g3, PSR_IMPL_LEON
be leon_remap /* It is a LEON - jump */
nop
/* Sanity-check, is MMU enabled */
lda [%g0] ASI_M_MMUREGS, %g1
andcc %g1, 1, %g0
be halt_notsup
nop
/* Check for a viking (TI) module. */
cmp %g3, PSR_IMPL_TI
bne srmmu_not_viking
nop
/* Figure out what kind of viking we are on.
* We need to know if we have to play with the
* AC bit and disable traps or not.
*/
/* I've only seen MicroSparc's on SparcClassics with this
* bit set.
*/
set 0x800, %g2
lda [%g0] ASI_M_MMUREGS, %g3 ! peek in the control reg
and %g2, %g3, %g3
subcc %g3, 0x0, %g0
bnz srmmu_not_viking ! is in mbus mode
nop
rd %psr, %g3 ! DO NOT TOUCH %g3
andn %g3, PSR_ET, %g2
wr %g2, 0x0, %psr
WRITE_PAUSE
/* Get context table pointer, then convert to
* a physical address, which is 36 bits.
*/
set AC_M_CTPR, %g4
lda [%g4] ASI_M_MMUREGS, %g4
sll %g4, 0x4, %g4 ! We use this below
! DO NOT TOUCH %g4
/* Set the AC bit in the Viking's MMU control reg. */
lda [%g0] ASI_M_MMUREGS, %g5 ! DO NOT TOUCH %g5
set 0x8000, %g6 ! AC bit mask
or %g5, %g6, %g6 ! Or it in...
sta %g6, [%g0] ASI_M_MMUREGS ! Close your eyes...
/* Grrr, why does it seem like every other load/store
* on the sun4m is in some ASI space...
* Fine with me, let's get the pointer to the level 1
* page table directory and fetch its entry.
*/
lda [%g4] ASI_M_BYPASS, %o1 ! This is a level 1 ptr
srl %o1, 0x4, %o1 ! Clear low 4 bits
sll %o1, 0x8, %o1 ! Make physical
/* Ok, pull in the PTD. */
lda [%o1] ASI_M_BYPASS, %o2 ! This is the 0x0 16MB pgd
/* Calculate to KERNBASE entry. */
add %o1, KERNBASE >> (PGDIR_SHIFT - 2), %o3
/* Poke the entry into the calculated address. */
sta %o2, [%o3] ASI_M_BYPASS
/* I don't get it Sun, if you engineered all these
* boot loaders and the PROM (thank you for the debugging
* features btw) why did you not have them load kernel
* images up in high address space, since this is necessary
* for ABI compliance anyways? Does this low-mapping provide
* enhanced interoperability?
*
* "The PROM is the computer."
*/
/* Ok, restore the MMU control register we saved in %g5 */
sta %g5, [%g0] ASI_M_MMUREGS ! POW... ouch
/* Turn traps back on. We saved it in %g3 earlier. */
wr %g3, 0x0, %psr ! tick tock, tick tock
/* Now we burn precious CPU cycles due to bad engineering. */
WRITE_PAUSE
/* Wow, all that just to move a 32-bit value from one
* place to another... Jump to high memory.
*/
b go_to_highmem
nop
srmmu_not_viking:
/* This works on viking's in Mbus mode and all
* other MBUS modules. It is virtually the same as
* the above madness sans turning traps off and flipping
* the AC bit.
*/
set AC_M_CTPR, %g1
lda [%g1] ASI_M_MMUREGS, %g1 ! get ctx table ptr
sll %g1, 0x4, %g1 ! make physical addr
lda [%g1] ASI_M_BYPASS, %g1 ! ptr to level 1 pg_table
srl %g1, 0x4, %g1
sll %g1, 0x8, %g1 ! make phys addr for l1 tbl
lda [%g1] ASI_M_BYPASS, %g2 ! get level1 entry for 0x0
add %g1, KERNBASE >> (PGDIR_SHIFT - 2), %g3
sta %g2, [%g3] ASI_M_BYPASS ! place at KERNBASE entry
b go_to_highmem
nop ! wheee....
leon_remap:
/* Sanity-check, is MMU enabled */
lda [%g0] ASI_LEON_MMUREGS, %g1
andcc %g1, 1, %g0
be halt_notsup
nop
/* Same code as in the srmmu_not_viking case,
* with the LEON ASI for mmuregs
*/
set AC_M_CTPR, %g1
lda [%g1] ASI_LEON_MMUREGS, %g1 ! get ctx table ptr
sll %g1, 0x4, %g1 ! make physical addr
lda [%g1] ASI_M_BYPASS, %g1 ! ptr to level 1 pg_table
srl %g1, 0x4, %g1
sll %g1, 0x8, %g1 ! make phys addr for l1 tbl
lda [%g1] ASI_M_BYPASS, %g2 ! get level1 entry for 0x0
add %g1, KERNBASE >> (PGDIR_SHIFT - 2), %g3
sta %g2, [%g3] ASI_M_BYPASS ! place at KERNBASE entry
b go_to_highmem
nop ! wheee....
/* Now do a non-relative jump so that PC is in high-memory */
go_to_highmem:
set execute_in_high_mem, %g1
jmpl %g1, %g0
nop
/* The code above should be at beginning and we have to take care about
* short jumps, as branching to .init.text section from .text is usually
* impossible */
__INIT
/* Acquire boot time privileged register values, this will help debugging.
* I figure out and store nwindows and nwindowsm1 later on.
*/
execute_in_high_mem:
mov %l0, %o0 ! put back romvec
mov %l1, %o1 ! and debug_vec
sethi %hi(prom_vector_p), %g1
st %o0, [%g1 + %lo(prom_vector_p)]
sethi %hi(linux_dbvec), %g1
st %o1, [%g1 + %lo(linux_dbvec)]
/* Get the machine type via the romvec
* getprops node operation
*/
add %g7, 0x1c, %l1
ld [%l1], %l0
ld [%l0], %l0
call %l0
or %g0, %g0, %o0 ! next_node(0) = first_node
or %o0, %g0, %g6
sethi %hi(cputypvar), %o1 ! First node has cpu-arch
or %o1, %lo(cputypvar), %o1
sethi %hi(cputypval), %o2 ! information, the string
or %o2, %lo(cputypval), %o2
ld [%l1], %l0 ! 'compatible' tells
ld [%l0 + 0xc], %l0 ! that we want 'sun4x' where
call %l0 ! x is one of 'm', 'd' or 'e'.
nop ! %o2 holds pointer
! to a buf where above string
! will get stored by the prom.
/* Check value of "compatible" property.
* "value" => "model"
* leon => sparc_leon
* sun4m => sun4m
* sun4s => sun4m
* sun4d => sun4d
* sun4e => "no_sun4e_here"
* '*' => "no_sun4u_here"
* Check single letters only
*/
set cputypval, %o2
/* If cputypval[0] == 'l' (lower case letter L) this is leon */
ldub [%o2], %l1
cmp %l1, 'l'
be leon_init
nop
/* Check cputypval[4] to find the sun model */
ldub [%o2 + 0x4], %l1
cmp %l1, 'm'
be sun4m_init
cmp %l1, 's'
be sun4m_init
cmp %l1, 'd'
be sun4d_init
cmp %l1, 'e'
be no_sun4e_here ! Could be a sun4e.
nop
b no_sun4u_here ! AIEEE, a V9 sun4u... Get our BIG BROTHER kernel :))
nop
leon_init:
/* LEON CPU - set boot_cpu_id */
sethi %hi(boot_cpu_id), %g2 ! boot-cpu index
#ifdef CONFIG_SMP
ldub [%g2 + %lo(boot_cpu_id)], %g1
cmp %g1, 0xff ! unset means first CPU
bne leon_smp_cpu_startup ! continue only with master
nop
#endif
/* Get CPU-ID from most significant 4-bit of ASR17 */
rd %asr17, %g1
srl %g1, 28, %g1
/* Update boot_cpu_id only on boot cpu */
stub %g1, [%g2 + %lo(boot_cpu_id)]
ba continue_boot
nop
/* CPUID in bootbus can be found at PA 0xff0140000 */
#define SUN4D_BOOTBUS_CPUID 0xf0140000
sun4d_init:
/* Need to patch call to handler_irq */
set patch_handler_irq, %g4
set sun4d_handler_irq, %g5
sethi %hi(0x40000000), %g3 ! call
sub %g5, %g4, %g5
srl %g5, 2, %g5
or %g5, %g3, %g5
st %g5, [%g4]
#ifdef CONFIG_SMP
/* Get our CPU id out of bootbus */
set SUN4D_BOOTBUS_CPUID, %g3
lduba [%g3] ASI_M_CTL, %g3
and %g3, 0xf8, %g3
srl %g3, 3, %g4
sta %g4, [%g0] ASI_M_VIKING_TMP1
sethi %hi(boot_cpu_id), %g5
stb %g4, [%g5 + %lo(boot_cpu_id)]
#endif
/* Fall through to sun4m_init */
sun4m_init:
/* Ok, the PROM could have done funny things and apple cider could still
* be sitting in the fault status/address registers. Read them all to
* clear them so we don't get magic faults later on.
*/
/* This sucks, apparently this makes Vikings call prom panic, will fix later */
2:
rd %psr, %o1
srl %o1, PSR_IMPL_SHIFT, %o1 ! Get a type of the CPU
subcc %o1, PSR_IMPL_TI, %g0 ! TI: Viking or MicroSPARC
be continue_boot
nop
set AC_M_SFSR, %o0
lda [%o0] ASI_M_MMUREGS, %g0
set AC_M_SFAR, %o0
lda [%o0] ASI_M_MMUREGS, %g0
/* Fujitsu MicroSPARC-II has no asynchronous flavors of FARs */
subcc %o1, 0, %g0
be continue_boot
nop
set AC_M_AFSR, %o0
lda [%o0] ASI_M_MMUREGS, %g0
set AC_M_AFAR, %o0
lda [%o0] ASI_M_MMUREGS, %g0
nop
continue_boot:
/* Aieee, now set PC and nPC, enable traps, give ourselves a stack and it's
* show-time!
*/
/* Turn on Supervisor, EnableFloating, and all the PIL bits.
* Also puts us in register window zero with traps off.
*/
set (PSR_PS | PSR_S | PSR_PIL | PSR_EF), %g2
wr %g2, 0x0, %psr
WRITE_PAUSE
/* I want a kernel stack NOW! */
set init_thread_union, %g1
set (THREAD_SIZE - STACKFRAME_SZ - TRACEREG_SZ), %g2
add %g1, %g2, %sp
mov 0, %fp /* And for good luck */
/* Zero out our BSS section. */
set __bss_start , %o0 ! First address of BSS
set _end , %o1 ! Last address of BSS
add %o0, 0x1, %o0
1:
stb %g0, [%o0]
subcc %o0, %o1, %g0
bl 1b
add %o0, 0x1, %o0
/* If boot_cpu_id has not been setup by machine specific
* init-code above we default it to zero.
*/
sethi %hi(boot_cpu_id), %g2
ldub [%g2 + %lo(boot_cpu_id)], %g3
cmp %g3, 0xff
bne 1f
nop
mov %g0, %g3
stub %g3, [%g2 + %lo(boot_cpu_id)]
1: sll %g3, 2, %g3
/* Initialize the uwinmask value for init task just in case.
* But first make current_set[boot_cpu_id] point to something useful.
*/
set init_thread_union, %g6
set current_set, %g2
#ifdef CONFIG_SMP
st %g6, [%g2]
add %g2, %g3, %g2
#endif
st %g6, [%g2]
st %g0, [%g6 + TI_UWINMASK]
/* Compute NWINDOWS and stash it away. Now uses %wim trick explained
* in the V8 manual. Ok, this method seems to work, Sparc is cool...
* No, it doesn't work, have to play the save/readCWP/restore trick.
*/
wr %g0, 0x0, %wim ! so we do not get a trap
WRITE_PAUSE
save
rd %psr, %g3
restore
and %g3, 0x1f, %g3
add %g3, 0x1, %g3
mov 2, %g1
wr %g1, 0x0, %wim ! make window 1 invalid
WRITE_PAUSE
cmp %g3, 0x7
bne 2f
nop
/* Adjust our window handling routines to
* do things correctly on 7 window Sparcs.
*/
#define PATCH_INSN(src, dest) \
set src, %g5; \
set dest, %g2; \
ld [%g5], %g4; \
st %g4, [%g2];
/* Patch for window spills... */
PATCH_INSN(spnwin_patch1_7win, spnwin_patch1)
PATCH_INSN(spnwin_patch2_7win, spnwin_patch2)
PATCH_INSN(spnwin_patch3_7win, spnwin_patch3)
/* Patch for window fills... */
PATCH_INSN(fnwin_patch1_7win, fnwin_patch1)
PATCH_INSN(fnwin_patch2_7win, fnwin_patch2)
/* Patch for trap entry setup... */
PATCH_INSN(tsetup_7win_patch1, tsetup_patch1)
PATCH_INSN(tsetup_7win_patch2, tsetup_patch2)
PATCH_INSN(tsetup_7win_patch3, tsetup_patch3)
PATCH_INSN(tsetup_7win_patch4, tsetup_patch4)
PATCH_INSN(tsetup_7win_patch5, tsetup_patch5)
PATCH_INSN(tsetup_7win_patch6, tsetup_patch6)
/* Patch for returning from traps... */
PATCH_INSN(rtrap_7win_patch1, rtrap_patch1)
PATCH_INSN(rtrap_7win_patch2, rtrap_patch2)
PATCH_INSN(rtrap_7win_patch3, rtrap_patch3)
PATCH_INSN(rtrap_7win_patch4, rtrap_patch4)
PATCH_INSN(rtrap_7win_patch5, rtrap_patch5)
/* Patch for killing user windows from the register file. */
PATCH_INSN(kuw_patch1_7win, kuw_patch1)
/* Now patch the kernel window flush sequences.
* This saves 2 traps on every switch and fork.
*/
set 0x01000000, %g4
set flush_patch_one, %g5
st %g4, [%g5 + 0x18]
st %g4, [%g5 + 0x1c]
set flush_patch_two, %g5
st %g4, [%g5 + 0x18]
st %g4, [%g5 + 0x1c]
set flush_patch_three, %g5
st %g4, [%g5 + 0x18]
st %g4, [%g5 + 0x1c]
set flush_patch_four, %g5
st %g4, [%g5 + 0x18]
st %g4, [%g5 + 0x1c]
set flush_patch_exception, %g5
st %g4, [%g5 + 0x18]
st %g4, [%g5 + 0x1c]
set flush_patch_switch, %g5
st %g4, [%g5 + 0x18]
st %g4, [%g5 + 0x1c]
2:
sethi %hi(nwindows), %g4
st %g3, [%g4 + %lo(nwindows)] ! store final value
sub %g3, 0x1, %g3
sethi %hi(nwindowsm1), %g4
st %g3, [%g4 + %lo(nwindowsm1)]
/* Here we go, start using Linux's trap table... */
set trapbase, %g3
wr %g3, 0x0, %tbr
WRITE_PAUSE
/* Finally, turn on traps so that we can call c-code. */
rd %psr, %g3
wr %g3, 0x0, %psr
WRITE_PAUSE
wr %g3, PSR_ET, %psr
WRITE_PAUSE
/* Call sparc32_start_kernel(struct linux_romvec *rp) */
sethi %hi(prom_vector_p), %g5
ld [%g5 + %lo(prom_vector_p)], %o0
call sparc32_start_kernel
nop
/* We should not get here. */
call halt_me
nop
no_sun4e_here:
ld [%g7 + 0x68], %o1
set sun4e_notsup, %o0
call %o1
nop
b halt_me
nop
__INITDATA
sun4u_1:
.asciz "finddevice"
.align 4
sun4u_2:
.asciz "/chosen"
.align 4
sun4u_3:
.asciz "getprop"
.align 4
sun4u_4:
.asciz "stdout"
.align 4
sun4u_5:
.asciz "write"
.align 4
sun4u_6:
.asciz "\n\rOn sun4u you have to use sparc64 kernel\n\rand not a sparc32 version\n\r\n\r"
sun4u_6e:
.align 4
sun4u_7:
.asciz "exit"
.align 8
sun4u_a1:
.word 0, sun4u_1, 0, 1, 0, 1, 0, sun4u_2, 0
sun4u_r1:
.word 0
sun4u_a2:
.word 0, sun4u_3, 0, 4, 0, 1, 0
sun4u_i2:
.word 0, 0, sun4u_4, 0, sun4u_1, 0, 8, 0
sun4u_r2:
.word 0
sun4u_a3:
.word 0, sun4u_5, 0, 3, 0, 1, 0
sun4u_i3:
.word 0, 0, sun4u_6, 0, sun4u_6e - sun4u_6 - 1, 0
sun4u_r3:
.word 0
sun4u_a4:
.word 0, sun4u_7, 0, 0, 0, 0
sun4u_r4:
__INIT
no_sun4u_here:
set sun4u_a1, %o0
set current_pc, %l2
cmp %l2, %g3
be 1f
mov %o4, %l0
sub %g3, %l2, %l6
add %o0, %l6, %o0
mov %o0, %l4
mov sun4u_r4 - sun4u_a1, %l3
ld [%l4], %l5
2:
add %l4, 4, %l4
cmp %l5, %l2
add %l5, %l6, %l5
bgeu,a 3f
st %l5, [%l4 - 4]
3:
subcc %l3, 4, %l3
bne 2b
ld [%l4], %l5
1:
call %l0
mov %o0, %l1
ld [%l1 + (sun4u_r1 - sun4u_a1)], %o1
add %l1, (sun4u_a2 - sun4u_a1), %o0
call %l0
st %o1, [%o0 + (sun4u_i2 - sun4u_a2)]
ld [%l1 + (sun4u_1 - sun4u_a1)], %o1
add %l1, (sun4u_a3 - sun4u_a1), %o0
call %l0
st %o1, [%o0 + (sun4u_i3 - sun4u_a3)]
call %l0
add %l1, (sun4u_a4 - sun4u_a1), %o0
/* Not reached */
halt_me:
ld [%g7 + 0x74], %o0
call %o0 ! Get us out of here...
nop ! Apparently Solaris is better.
/* Ok, now we continue in the .data/.text sections */
.data
.align 4
/*
* Fill up the prom vector, note in particular the kind first element,
* no joke. I don't need all of them in here as the entire prom vector
* gets initialized in c-code so all routines can use it.
*/
prom_vector_p:
.word 0
/* We calculate the following at boot time, window fills/spills and trap entry
* code uses these to keep track of the register windows.
*/
.align 4
.globl nwindows
.globl nwindowsm1
nwindows:
.word 8
nwindowsm1:
.word 7
/* Boot time debugger vector value. We need this later on. */
.align 4
.globl linux_dbvec
linux_dbvec:
.word 0
.word 0
.align 8
.globl lvl14_save
lvl14_save:
.word 0
.word 0
.word 0
.word 0
.word t_irq14