diff options
| -rw-r--r-- | psp/mips_stub.S | 36 |
1 files changed, 16 insertions, 20 deletions
diff --git a/psp/mips_stub.S b/psp/mips_stub.S index 031e4b5..420f602 100644 --- a/psp/mips_stub.S +++ b/psp/mips_stub.S @@ -277,19 +277,17 @@ mips_indirect_branch_dual: lui $2, %hi(\ftable) addu $2, $2, $1 lw $2, %lo(\ftable)($2) # new function handler is in $2 - srl $2, $2, 2 # remove lower two bits + sll $1, $2, 4 # shift left by 4 (6 LSB are zero) + ori $1, $1, 3 # Insert the opcode in the LSB + ror $1, $1, 6 # Rotate to the opcode is now in the MSB - lui $1, %hi(3 << 26) # $1 = 3 (JAL opcode) - ins $1, $2, 0, 26 # insert offset into jal + sw $1, -8($ra) # Overwrite jal instruction w/ new handler - addiu $ra, $ra, -8 # rewind return address to function call - sw $1, ($ra) # modify to call new handler - - cache 0x1a, ($ra) # hit writeback dcache line - cache 0x08, ($ra) # hit invalidate icache line + cache 0x1a, -8($ra) # hit writeback dcache line + cache 0x08, -8($ra) # hit invalidate icache line + jr $2 # Jump to new handler directly + nop - jr $ra # return - nop # wary of putting cache here .endm @@ -311,19 +309,17 @@ mips_indirect_branch_dual: addu $2, $2, $1 lw $2, %lo(\ftable)($2) # new function handler is in $2 - srl $2, $2, 2 # remove lower two bits + sll $1, $2, 4 # Build the new JAL instruction + ori $1, $1, 3 # same as above. + ror $1, $1, 6 - lui $1, %hi(3 << 26) # $1 = 3 (JAL opcode) - ins $1, $2, 0, 26 # insert offset into jal + sw $1, -8($ra) # modify to call new handler - addiu $ra, $ra, -8 # rewind return address to function call - sw $1, ($ra) # modify to call new handler - - cache 0x1a, ($ra) # hit writeback dcache line - cache 0x08, ($ra) # hit invalidate icache line + cache 0x1a, -8($ra) # hit writeback dcache line + cache 0x08, -8($ra) # hit invalidate icache line + jr $2 # Jump to new handler + nop - jr $ra # return - nop # wary of putting cache here .endm |