From 8969934d3180d80b4cb5da225e25379a880b5476 Mon Sep 17 00:00:00 2001 From: Nick Clifton Date: Thu, 8 May 2014 08:53:16 +0100 Subject: [PATCH] Add support for emulating the MSP430 hardware multiply feature. * msp430-sim.c (sim_open): Do not allocate memory over the hardware multiply registers. (get_op): Add support for reads from the hardware multiply registers. (put_op): Add support for writes to the hardware multiply registers. (msp430_step_once): Add support for the RETI instruction used by the CPUX architecture. --- sim/msp430/ChangeLog | 11 +++ sim/msp430/msp430-sim.c | 204 ++++++++++++++++++++++++++++++++++++++++++------ 2 files changed, 192 insertions(+), 23 deletions(-) diff --git a/sim/msp430/ChangeLog b/sim/msp430/ChangeLog index 484a5d2..4b76a03 100644 --- a/sim/msp430/ChangeLog +++ b/sim/msp430/ChangeLog @@ -1,3 +1,14 @@ +2014-05-08 Nick Clifton + + * msp430-sim.c (sim_open): Do not allocate memory over the + hardware multiply registers. + (get_op): Add support for reads from the hardware multiply + registers. + (put_op): Add support for writes to the hardware multiply + registers. + (msp430_step_once): Add support for the RETI instruction used by + the CPUX architecture. + 2014-03-10 Mike Frysinger * msp430-sim.c (sim_create_inferior): Set new_pc to the result of diff --git a/sim/msp430/msp430-sim.c b/sim/msp430/msp430-sim.c index 2a648f5..693fdee 100644 --- a/sim/msp430/msp430-sim.c +++ b/sim/msp430/msp430-sim.c @@ -175,8 +175,10 @@ sim_open (SIM_OPEN_KIND kind, CPU_REG_STORE (MSP430_CPU (sd)) = msp430_reg_store; /* Allocate memory if none specified by user. */ + if (sim_core_read_buffer (sd, MSP430_CPU (sd), read_map, &c, 0x130, 1) == 0) + sim_do_commandf (sd, "memory-region 0,0x20"); if (sim_core_read_buffer (sd, MSP430_CPU (sd), read_map, &c, 0x200, 1) == 0) - sim_do_commandf (sd, "memory-region 0,0x10000"); + sim_do_commandf (sd, "memory-region 0x200,0xffe00"); if (sim_core_read_buffer (sd, MSP430_CPU (sd), read_map, &c, 0xfffe, 1) == 0) sim_do_commandf (sd, "memory-region 0xfffe,2"); if (sim_core_read_buffer (sd, MSP430_CPU (sd), read_map, &c, 0x10000, 1) == 0) @@ -314,6 +316,40 @@ trace_reg_get (SIM_DESC sd, int n) #define REG_PUT(N,V) trace_reg_put (sd, N, V) #define REG_GET(N) trace_reg_get (sd, N) +/* Hardware multiply (and accumulate) support. */ +static enum { UNSIGN_32, SIGN_32, UNSIGN_MAC_32, SIGN_MAC_32 } hwmult_type; +static unsigned32 hwmult_op1; +static unsigned32 hwmult_op2; +static unsigned32 hwmult_result; +static signed32 hwmult_signed_result; +static unsigned32 hwmult_accumulator; +static signed32 hwmult_signed_accumulator; + +static enum { UNSIGN_64, SIGN_64 } hw32mult_type; +static unsigned64 hw32mult_op1; +static unsigned64 hw32mult_op2; +static unsigned64 hw32mult_result; + +static unsigned int +zero_ext (unsigned int v, unsigned int bits) +{ + v &= ((1 << bits) - 1); + return v; +} + +static signed int +sign_ext (signed int v, unsigned int bits) +{ + int sb = 1 << (bits-1); /* Sign bit. */ + int mb = (1 << (bits-1)) - 1; /* Mantissa bits. */ + + if (v & sb) + v = v | ~mb; + else + v = v & mb; + return v; +} + static int get_op (SIM_DESC sd, MSP430_Opcode_Decoded *opc, int n) { @@ -372,6 +408,71 @@ get_op (SIM_DESC sd, MSP430_Opcode_Decoded *opc, int n) if (addr == 0x5dd) rv = 2; #endif + if (addr >= 0x130 && addr <= 0x15B) + { + switch (addr) + { + case 0x13A: + rv = zero_ext (hwmult_result, 16); + break; + + case 0x13C: + switch (hwmult_type) + { + case UNSIGN_32: + rv = zero_ext (hwmult_result >> 16, 16); + break; + + case SIGN_32: + rv = sign_ext (hwmult_signed_result >> 16, 16); + break; + } + break; + + case 0x13E: + switch (hwmult_type) + { + case UNSIGN_32: + rv = 0; + break; + case SIGN_32: + rv = hwmult_signed_result < 0 ? -1 : 0; + break; + case UNSIGN_MAC_32: + rv = 0; /* FIXME: Should be carry of last accumulate. */ + break; + case SIGN_MAC_32: + rv = hwmult_signed_accumulator < 0 ? -1 : 0; + break; + } + break; + + case 0x154: + rv = zero_ext (hw32mult_result, 16); + break; + + case 0x156: + rv = zero_ext (hw32mult_result >> 16, 16); + break; + + case 0x158: + rv = zero_ext (hw32mult_result >> 32, 16); + break; + + case 0x15A: + switch (hw32mult_type) + { + case UNSIGN_64: rv = zero_ext (hw32mult_result >> 48, 16); break; + case SIGN_64: rv = sign_ext (hw32mult_result >> 48, 16); break; + } + break; + + default: + fprintf (stderr, "unimplemented HW MULT read!\n"); + break; + } + } + if (TRACE_MEMORY_P (MSP430_CPU (sd))) trace_generic (sd, MSP430_CPU (sd), TRACE_MEMORY_IDX, "GET: [%#x].%d -> %#x", addr, opc->size, rv); @@ -464,6 +565,77 @@ put_op (SIM_DESC sd, MSP430_Opcode_Decoded *opc, int n, int val) if (addr == 0x5ce) putchar (val); #endif + if (addr >= 0x130 && addr <= 0x15B) + { + signed int a,b; + + /* Hardware Multiply emulation. */ + assert (opc->size == 16); + + switch (addr) + { + case 0x130: hwmult_op1 = val; hwmult_type = UNSIGN_32; break; + case 0x132: hwmult_op1 = val; hwmult_type = SIGN_32; break; + case 0x134: hwmult_op1 = val; hwmult_type = UNSIGN_MAC_32; break; + case 0x136: hwmult_op1 = val; hwmult_type = SIGN_MAC_32; break; + + case 0x138: hwmult_op2 = val; + switch (hwmult_type) + { + case UNSIGN_32: + hwmult_result = hwmult_op1 * hwmult_op2; + hwmult_signed_result = (signed) hwmult_result; + hwmult_accumulator = hwmult_signed_accumulator = 0; + break; + + case SIGN_32: + a = sign_ext (hwmult_op1, 16); + b = sign_ext (hwmult_op2, 16); + hwmult_signed_result = a * b; + hwmult_result = (unsigned) hwmult_signed_result; + hwmult_accumulator = hwmult_signed_accumulator = 0; + break; + + case UNSIGN_MAC_32: + hwmult_accumulator += hwmult_op1 * hwmult_op2; + hwmult_signed_accumulator += hwmult_op1 * hwmult_op2; + hwmult_result = hwmult_signed_result = 0; + break; + + case SIGN_MAC_32: + a = sign_ext (hwmult_op1, 16); + b = sign_ext (hwmult_op2, 16); + hwmult_accumulator += a * b; + hwmult_signed_accumulator += a * b; + hwmult_result = hwmult_signed_result = 0; + break; + } + break; + + case 0x140: hw32mult_op1 = val; hw32mult_type = UNSIGN_64; break; + case 0x142: hw32mult_op1 = (hw32mult_op1 & 0xFFFF) | (val << 16); break; + case 0x144: hw32mult_op1 = val; hw32mult_type = SIGN_64; break; + case 0x146: hw32mult_op1 = (hw32mult_op1 & 0xFFFF) | (val << 16); break; + case 0x150: hw32mult_op2 = val; break; + + case 0x152: hw32mult_op2 = (hw32mult_op2 & 0xFFFF) | (val << 16); + switch (hw32mult_type) + { + case UNSIGN_64: + hw32mult_result = hw32mult_op1 * hw32mult_op2; + break; + case SIGN_64: + hw32mult_result = sign_ext (hw32mult_op1, 32) * sign_ext (hw32mult_op2, 32); + break; + } + break; + + default: + fprintf (stderr, "unimplemented HW MULT write to %x!\n", addr); + break; + } + } + switch (opc->size) { case 8: @@ -640,26 +812,6 @@ msp430_dis_read (bfd_vma memaddr, #define POS(x) (((x) & SIGN) ? 0 : 1) #define NEG(x) (((x) & SIGN) ? 1 : 0) -static int -zero_ext (int v, int bits) -{ - v &= ((1 << bits) - 1); - return v; -} - -static int -sign_ext (int v, int bits) -{ - int sb = 1 << (bits-1); /* Sign bit. */ - int mb = (1 << (bits-1)) - 1; /* Mantissa bits. */ - - if (v & sb) - v = v | ~mb; - else - v = v & mb; - return v; -} - #define SX(v) sign_ext (v, opcode->size) #define ZX(v) zero_ext (v, opcode->size) @@ -1350,10 +1502,16 @@ msp430_step_once (SIM_DESC sd) break; case MSO_reti: - SR = mem_get_val (sd, SP, op_bits); + u1 = mem_get_val (sd, SP, 16); + SR = u1 & 0xFF; SP += 2; - PC = mem_get_val (sd, SP, op_bits); + PC = mem_get_val (sd, SP, 16); SP += 2; + /* Emulate the RETI action of the 20-bit CPUX architecure. + This is safe for 16-bit CPU architectures as well, since the top + 8-bits of SR will have been written to the stack here, and will + have been read as 0. */ + PC |= (u1 & 0xF000) << 4; if (TRACE_ALU_P (MSP430_CPU (sd))) trace_generic (sd, MSP430_CPU (sd), TRACE_ALU_IDX, "RETI: pc %#x sr %#x", -- 2.7.4