diff options
Diffstat (limited to 'qemu/roms/openbios/arch/sparc32/wof.S')
| -rw-r--r-- | qemu/roms/openbios/arch/sparc32/wof.S | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/qemu/roms/openbios/arch/sparc32/wof.S b/qemu/roms/openbios/arch/sparc32/wof.S new file mode 100644 index 000000000..8d6bb7314 --- /dev/null +++ b/qemu/roms/openbios/arch/sparc32/wof.S @@ -0,0 +1,133 @@ +/* + * Proll takes this from Sparclinux kernel, ruthlessly truncated + * because we have no user windows. + * + * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu) + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * version 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, + * MA 02110-1301, USA. + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License V2 + * as published by the Free Software Foundation + */ + +// #include <asm/winmacro.h> +// #include <asm/asmmacro.h> + +/* Reg_window offsets */ +#define RW_L0 0x00 +#define RW_L1 0x04 +#define RW_L2 0x08 +#define RW_L3 0x0c +#define RW_L4 0x10 +#define RW_L5 0x14 +#define RW_L6 0x18 +#define RW_L7 0x1c +#define RW_I0 0x20 +#define RW_I1 0x24 +#define RW_I2 0x28 +#define RW_I3 0x2c +#define RW_I4 0x30 +#define RW_I5 0x34 +#define RW_I6 0x38 +#define RW_I7 0x3c + +/* Store the register window onto the 8-byte aligned area starting + * at %reg. It might be %sp, it might not, we don't care. + */ +#define STORE_WINDOW(reg) \ + std %l0, [%reg + RW_L0]; \ + std %l2, [%reg + RW_L2]; \ + std %l4, [%reg + RW_L4]; \ + std %l6, [%reg + RW_L6]; \ + std %i0, [%reg + RW_I0]; \ + std %i2, [%reg + RW_I2]; \ + std %i4, [%reg + RW_I4]; \ + std %i6, [%reg + RW_I6]; + +/* We define macro's for registers which have a fixed + * meaning throughout this entire routine. The 'T' in + * the comments mean that the register can only be + * accessed when in the 'trap' window, 'G' means + * accessible in any window. Do not change these registers + * after they have been set, until you are ready to return + * from the trap. + */ +#define t_psr l0 /* %psr at trap time T */ +#define t_pc l1 /* PC for trap return T */ +#define t_npc l2 /* NPC for trap return T */ +#define t_wim l3 /* %wim at trap time T */ +#define saved_g5 l5 /* Global save register T */ +#define saved_g6 l6 /* Global save register T */ + +/* Now registers whose values can change within the handler. */ +#define twin_tmp l4 /* Temp reg, only usable in trap window T */ +#define glob_tmp g5 /* Global temporary reg, usable anywhere G */ + + .text + .align 4 + + /* BEGINNING OF PATCH INSTRUCTIONS */ + /* On a 7-window Sparc the boot code patches spnwin_* + * instructions with the following ones. + */ + .globl spnwin_patch1_7win, spnwin_patch2_7win, spnwin_patch3_7win +spnwin_patch1_7win: sll %t_wim, 6, %glob_tmp +spnwin_patch2_7win: and %glob_tmp, 0x7f, %glob_tmp +spnwin_patch3_7win: and %twin_tmp, 0x7f, %twin_tmp + /* END OF PATCH INSTRUCTIONS */ + + /* The trap entry point has done the following: + * + * rd %psr, %l0 + * rd %wim, %l3 + * b spill_window_entry + * nop + */ + + .globl spill_window_entry + .globl spnwin_patch1, spnwin_patch2 +spill_window_entry: + /* LOCATION: Trap Window */ + + mov %g5, %saved_g5 ! save away global temp register + mov %g6, %saved_g6 ! save away 'current' ptr register + + /* Compute what the new %wim will be if we save the + * window properly in this trap handler. + * + * newwim = ((%wim>>1) | (%wim<<(nwindows - 1))); + */ + srl %t_wim, 0x1, %twin_tmp +spnwin_patch1: sll %t_wim, 7, %glob_tmp + or %glob_tmp, %twin_tmp, %glob_tmp +spnwin_patch2: and %glob_tmp, 0xff, %glob_tmp + + /* Save into the window which must be saved and do it. + */ + save %g0, %g0, %g0 ! save into the window to stash away + wr %glob_tmp, 0x0, %wim ! set new %wim, this is safe now + + /* LOCATION: Window to be saved */ + + STORE_WINDOW(sp) ! stash the window + restore %g0, %g0, %g0 ! go back into trap window + + /* LOCATION: Trap window */ + mov %saved_g5, %g5 ! restore %glob_tmp + mov %saved_g6, %g6 ! restore %curptr + wr %t_psr, 0x0, %psr ! restore condition codes in %psr + nop; nop; nop ! waste some time + jmp %t_pc ! Return from trap + rett %t_npc ! we are done |