diff options
Diffstat (limited to 'qemu/roms/openbios/arch/sparc32/switch.S')
| -rw-r--r-- | qemu/roms/openbios/arch/sparc32/switch.S | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/qemu/roms/openbios/arch/sparc32/switch.S b/qemu/roms/openbios/arch/sparc32/switch.S new file mode 100644 index 000000000..d5b1b659d --- /dev/null +++ b/qemu/roms/openbios/arch/sparc32/switch.S @@ -0,0 +1,154 @@ +#define __ASSEMBLY +#include "psr.h" +#include "asm/asi.h" +#define ASI_BP ASI_M_BYPASS +#define REGWIN_SZ 0x40 + + .globl __switch_context, __switch_context_nosave, __exit_context, halt + + .text + .align 4 + +#define STACKFRAME_SZ 0x60 + +/* These are just handy. */ +#define _SV save %sp, -STACKFRAME_SZ, %sp +#define _RS restore + +#define FLUSH_ALL_KERNEL_WINDOWS \ + _SV; _SV; _SV; _SV; _SV; _SV; _SV; \ + _RS; _RS; _RS; _RS; _RS; _RS; _RS; + +/* + * Switch execution context + * This saves registers in the stack, then + * switches the stack, and restores everything from the new stack. + * This function takes no argument. New stack pointer is + * taken from global variable __context, and old stack pointer + * is also saved to __context. This way we can just jump to + * this routine to get back to the original context. + */ + +__switch_context: + FLUSH_ALL_KERNEL_WINDOWS + /* Save everything in stack */ + st %fp, [%fp + 120 -144] + add %fp, -144, %fp + st %g1, [%fp + 4] + st %g2, [%fp + 8] + st %g3, [%fp + 12] + st %g4, [%fp + 16] + st %g5, [%fp + 20] + st %g6, [%fp + 24] + st %g7, [%fp + 28] + + st %o0, [%fp + 32] + st %o1, [%fp + 36] + st %o2, [%fp + 40] + st %o3, [%fp + 44] + st %o4, [%fp + 48] + st %o5, [%fp + 52] + st %sp, [%fp + 56] + st %o7, [%fp + 60] + + st %l0, [%fp + 64] + st %l1, [%fp + 68] + st %l2, [%fp + 72] + st %l3, [%fp + 76] + st %l4, [%fp + 80] + st %l5, [%fp + 84] + st %l6, [%fp + 88] + st %l7, [%fp + 92] + + st %i0, [%fp + 96] + st %i1, [%fp + 100] + st %i2, [%fp + 104] + st %i3, [%fp + 108] + st %i4, [%fp + 112] + st %i5, [%fp + 116] + st %i7, [%fp + 124] + + /* ctx->return_address: Return to caller */ + st %o7, [%fp + 128] + + /* Interrupts are not allowed... */ + + /* Turn on Supervisor, EnableFloating, and all the PIL bits. + * Also puts us in register window zero with traps off. + */ +#if 0 + set (PSR_PS | PSR_S | PSR_PIL | PSR_EF), %g2 + wr %g2, 0x0, %psr +#endif + set __context, %g1 + /* Swap ctx pointer with %fp and jump*/ + ba __set_context + swap [%g1], %fp +__switch_context_nosave: + set __context, %g1 + /* load %fp from ctx pointer */ + ld [%g1], %fp +__set_context: + /* Load all registers */ + /* offset 0: %g0, no need to load */ + ld [%fp + 4], %g1 + ld [%fp + 8], %g2 + ld [%fp + 12], %g3 + ld [%fp + 16], %g4 + ld [%fp + 20], %g5 + ld [%fp + 24], %g6 + ld [%fp + 28], %g7 + + /* offset 32: %o0, loaded from ctx->param */ + ld [%fp + 36], %o1 + ld [%fp + 40], %o2 + ld [%fp + 44], %o3 + ld [%fp + 48], %o4 + ld [%fp + 52], %o5 + ld [%fp + 56], %sp + /* offset 60: %o7, loaded from ctx->return_addr */ + + ld [%fp + 64], %l0 + ld [%fp + 68], %l1 + ld [%fp + 72], %l2 + ld [%fp + 76], %l3 + ld [%fp + 80], %l4 + ld [%fp + 84], %l5 + ld [%fp + 88], %l6 + ld [%fp + 92], %l7 + + ld [%fp + 96], %i0 + ld [%fp + 100], %i1 + ld [%fp + 104], %i2 + ld [%fp + 108], %i3 + ld [%fp + 112], %i4 + ld [%fp + 116], %i5 + ld [%fp + 124], %i7 + + /* ctx->return_addr */ + ld [%fp + 136], %o7 + + /* ctx->param */ + ld [%fp + 140], %o0 + + /* ctx->pc, save %g1 to %y and load to %g1 */ + mov %g1, %y + ld [%fp + 128], %g1 + /* %fp last */ + ld [%fp + 120], %fp + /* Finally, get the new %pc from %g1 and restore %g1*/ + jmp %g1 + mov %y, %g1 + + FLUSH_ALL_KERNEL_WINDOWS +__exit_context: + /* Get back to the original context */ + call __switch_context + nop + + /* We get here if the other context attempt to switch to this + * dead context. This should not happen. */ + +halt: + b halt + nop |