[OpenOCD-devel] [PATCH]: f81af96 mips32: restore working regs after execption

[<ge...@op...>]

This is an automated email from Gerrit.

Salvador Arroyo (sar...@ya...) just uploaded a new patch set to Gerrit, which you can find at http://openocd.zylin.com/4146

-- gerrit

commit f81af9626bea22297a7b7d6e5f7da30d77a3fe20
Author: Salvador Arroyo <sar...@ya...>
Date:   Mon May 22 20:14:18 2017 +0200

    mips32: restore working regs after execption
    
    If an exception is taken, execution does not complete
    and registers are not restored. Added a new function
    for restoring registers.
    
    Change-Id: Idf7f848777d6adf18dc43ec323ea1a8577aa8cd4
    Signed-off-by: Salvador Arroyo <sar...@ya...>

diff --git a/src/target/mips32_pracc.c b/src/target/mips32_pracc.c
index da2a906..0255063 100644
--- a/src/target/mips32_pracc.c
+++ b/src/target/mips32_pracc.c
@@ -155,7 +155,7 @@ int mips32_pracc_clean_text_jump(struct mips_ejtag *ejtag_info)
 	return ERROR_OK;
 }
 
-static void pracc_log_debug_mode_exception_info(struct mips_ejtag *ejtag_info)
+static void pracc_log_debug_mode_exception_info(struct mips_ejtag *ejtag_info, bool restore_regs)
 {
 	if (ejtag_info->exception_check)	/* avoid recursive calls */
 		return;
@@ -168,11 +168,14 @@ static void pracc_log_debug_mode_exception_info(struct mips_ejtag *ejtag_info)
 	if (retval == ERROR_OK)
 		retval = mips32_cp0_read(ejtag_info, &exc_addr, 24, 0);	/* read Cp0 DEPC register */
 
-	ejtag_info->exception_check = 0;
-
 	if (retval == ERROR_OK && (val & EJTAG_DEBUG_CAUSE_MASK) == 0)
 		LOG_WARNING("Debug mode exception, code: %s, triggered at address: %"PRIx32,
 			excep_code[(val & EJTAG_DEBUG_EXCEPCODE_MASK) >> EJTAG_DEBUG_EXCEPCODE_SHIFT], exc_addr);
+
+	if (restore_regs)	/* current pracc functions only take 3 registers at most */
+		mips32_pracc_restore_working_regs(ejtag_info, 8, 9);	/* restore $8, $9 and $15 */
+
+	ejtag_info->exception_check = 0;
 }
 
 int mips32_pracc_exec(struct mips_ejtag *ejtag_info, struct pracc_queue_info *ctx,
@@ -379,7 +382,7 @@ inline void pracc_queue_free(struct pracc_queue_info *ctx)
 
 	if (ctx->retval == ERROR_PRACC_TEXT_JUMP) {
 		ctx->retval = ERROR_JTAG_DEVICE_ERROR;	/* change to standard error code */
-		pracc_log_debug_mode_exception_info(ctx->ejtag_info);
+		pracc_log_debug_mode_exception_info(ctx->ejtag_info, 1);
 	}
 }
 
@@ -486,6 +489,30 @@ exit:
 	return retval;
 }
 
+int mips32_pracc_restore_working_regs(struct mips_ejtag *ejtag_info, unsigned first, unsigned last)
+{
+	if (last > 15 || first > last)
+		return ERROR_FAIL;
+
+	struct pracc_queue_info ctx = {.ejtag_info = ejtag_info};
+	pracc_queue_init(&ctx);
+
+	for (unsigned i = first; i <= last; i++)
+		pracc_add_li32(&ctx, i, ejtag_info->regs[i], 1);
+
+	pracc_add(&ctx, 0, MIPS32_B(ctx.isa, NEG16((ctx.code_count + 1) << ctx.isa)));
+	/* restore reg 15 from DeSave except if last == 15 */
+	last == 15 ? pracc_add(&ctx, 0, MIPS32_MTC0(ctx.isa, 15, 31, 0)) :	/* load $15 in DeSave */
+		pracc_add(&ctx, 0, MIPS32_MFC0(ctx.isa, 15, 31, 0));		/* restore $15 from DeSave */
+
+	ctx.retval = mips32_pracc_queue_exec(ejtag_info, &ctx, NULL, 1);
+	pracc_queue_free(&ctx);
+
+	if (ctx.retval != ERROR_OK)
+		LOG_ERROR("Failed to restore working registers");
+	return ctx.retval;
+}
+
 int mips32_pracc_read_u32(struct mips_ejtag *ejtag_info, uint32_t addr, uint32_t *buf)
 {
 	struct pracc_queue_info ctx = {.ejtag_info = ejtag_info};
diff --git a/src/target/mips32_pracc.h b/src/target/mips32_pracc.h
index 8181c9b..e4fe04d 100644
--- a/src/target/mips32_pracc.h
+++ b/src/target/mips32_pracc.h
@@ -117,7 +117,7 @@ int mips32_pracc_write_regs(struct mips_ejtag *ejtag_info, uint32_t *regs);
 
 int mips32_pracc_exec(struct mips_ejtag *ejtag_info, struct pracc_queue_info *ctx,
 				uint32_t *param_out, bool check_last);
-
+int mips32_pracc_restore_working_regs(struct mips_ejtag *ejtag_info, unsigned first, unsigned last);
 /**
  * \b mips32_cp0_read
  *

--