simplify XScale debug handler installation
authorDavid Brownell <dbrownell@users.sourceforge.net>
Mon, 12 Oct 2009 09:39:18 +0000 (02:39 -0700)
committerDavid Brownell <dbrownell@users.sourceforge.net>
Mon, 12 Oct 2009 09:39:18 +0000 (02:39 -0700)
Load the XScale debug handler from the read-only data section
instead of from a separate file that can get lost or garbaged.
This eliminates installation and versioning issues, and also
speeds up reset handling a bit.

Plus some minor bits of cleanup related to loading that handler:
comments about just what this handler does, and check fault codes
while writing it into the mini-icache.

The only behavioral changes should be cleaner failure modes after
errors during handler loading, and being a bit faster.

NOTE:  presumes GNU assembly syntax, with ".incbin"; and ELF,
because of the syntax of the ".size" directive.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
TODO
configure.in
src/target/Makefile.am
src/target/xscale.c
src/target/xscale.h
src/target/xscale_debug.S [new file with mode: 0644]

diff --git a/TODO b/TODO
index cf7778b..6521c60 100644 (file)
--- a/TODO
+++ b/TODO
@@ -125,9 +125,6 @@ Once the above are completed:
 
 - general layer cleanup: @par
   https://lists.berlios.de/pipermail/openocd-development/2009-May/006590.html
-- regression: xscale does not place debug_handler.bin into the right spot. workaround:
-  use -s option on command line to place xscale/debug_handler.bin in search path @par
-  https://lists.berlios.de/pipermail/openocd-development/2009-July/009338.html
 - bug: either USBprog is broken with new tms sequence or there is a general
   problem with XScale and the new tms sequence. Workaround: use "tms_sequence long"
   @par
index 8e2881c..84574be 100644 (file)
@@ -16,6 +16,7 @@ AC_LANG_C
 AC_PROG_CC
 AC_PROG_CC_C99
 AM_PROG_CC_C_O
+AM_PROG_AS
 AC_PROG_RANLIB
 
 dnl disable checks for C++, Fortran and GNU Java Compiler
index 9eee2f9..86716dc 100644 (file)
@@ -35,6 +35,7 @@ libtarget_la_SOURCES = \
        feroceon.c \
        etb.c \
        xscale.c \
+       xscale_debug.S \
        arm_simulator.c \
        image.c \
        armv7m.c \
@@ -98,7 +99,6 @@ noinst_HEADERS = \
        avrt.h
 
 nobase_dist_pkglib_DATA =
-nobase_dist_pkglib_DATA += xscale/debug_handler.bin
 nobase_dist_pkglib_DATA += ecos/at91eb40a.elf
 
 MAINTAINERCLEANFILES = $(srcdir)/Makefile.in
index fca578d..82a2c57 100644 (file)
@@ -1559,15 +1559,6 @@ static int xscale_deassert_reset(target_t *target)
 {
        armv4_5_common_t *armv4_5 = target->arch_info;
        xscale_common_t *xscale = armv4_5->arch_info;
-
-       fileio_t debug_handler;
-       uint32_t address;
-       uint32_t binary_size;
-
-       uint32_t buf_cnt;
-       uint32_t i;
-       int retval;
-
        breakpoint_t *breakpoint = target->breakpoints;
 
        LOG_DEBUG("-");
@@ -1592,6 +1583,11 @@ static int xscale_deassert_reset(target_t *target)
 
        if (!xscale->handler_installed)
        {
+               uint32_t address;
+               unsigned buf_cnt;
+               const uint8_t *buffer = xscale_debug_handler;
+               int retval;
+
                /* release SRST */
                jtag_add_reset(0, 0);
 
@@ -1606,36 +1602,26 @@ static int xscale_deassert_reset(target_t *target)
                buf_set_u32(xscale->reg_cache->reg_list[XSCALE_DCSR].value, 16, 1, 0x1);
                xscale_write_dcsr(target, 1, 0);
 
-               /* Load debug handler */
-               if (fileio_open(&debug_handler, "xscale/debug_handler.bin", FILEIO_READ, FILEIO_BINARY) != ERROR_OK)
-               {
-                       return ERROR_OK;
-               }
-
-               if ((binary_size = debug_handler.size) % 4)
-               {
-                       LOG_ERROR("debug_handler.bin: size not a multiple of 4");
-                       exit(-1);
-               }
-
-               if (binary_size > 0x800)
-               {
-                       LOG_ERROR("debug_handler.bin: larger than 2kb");
-                       exit(-1);
-               }
-
-               binary_size = CEIL(binary_size, 32) * 32;
-
+               /* Load the debug handler into the mini-icache.  Since
+                * it's using halt mode (not monitor mode), it runs in
+                * "Special Debug State" for access to registers, memory,
+                * coprocessors, trace data, etc.
+                *
+                * REVISIT:  *assumes* we've had a SRST+TRST reset so the
+                * mini-icache contents have been invalidated.  Safest to
+                * force that, so writing new contents is reliable...
+                */
                address = xscale->handler_address;
-               while (binary_size > 0)
+               for (unsigned binary_size = xscale_debug_handler_size;
+                               binary_size > 0;
+                               binary_size -= buf_cnt, buffer += buf_cnt)
                {
                        uint32_t cache_line[8];
-                       uint8_t buffer[32];
-
-                       if ((retval = fileio_read(&debug_handler, 32, buffer, &buf_cnt)) != ERROR_OK)
-                       {
+                       unsigned i;
 
-                       }
+                       buf_cnt = binary_size;
+                       if (buf_cnt > 32)
+                               buf_cnt = 32;
 
                        for (i = 0; i < buf_cnt; i += 4)
                        {
@@ -1651,15 +1637,23 @@ static int xscale_deassert_reset(target_t *target)
                        /* only load addresses other than the reset vectors */
                        if ((address % 0x400) != 0x0)
                        {
-                               xscale_load_ic(target, address, cache_line);
+                               retval = xscale_load_ic(target, address,
+                                               cache_line);
+                               if (retval != ERROR_OK)
+                                       return retval;
                        }
 
                        address += buf_cnt;
-                       binary_size -= buf_cnt;
                };
 
-               xscale_load_ic(target, 0x0, xscale->low_vectors);
-               xscale_load_ic(target, 0xffff0000, xscale->high_vectors);
+               retval = xscale_load_ic(target, 0x0,
+                                       xscale->low_vectors);
+               if (retval != ERROR_OK)
+                       return retval;
+               retval = xscale_load_ic(target, 0xffff0000,
+                                       xscale->high_vectors);
+               if (retval != ERROR_OK)
+                       return retval;
 
                jtag_add_runtest(30, jtag_set_end_state(TAP_IDLE));
 
@@ -1685,8 +1679,6 @@ static int xscale_deassert_reset(target_t *target)
                        /* resume the target */
                        xscale_resume(target, 1, 0x0, 1, 0);
                }
-
-               fileio_close(&debug_handler);
        }
        else
        {
@@ -3056,6 +3048,11 @@ static int xscale_target_create(struct target_s *target, Jim_Interp *interp)
 {
        xscale_common_t *xscale;
 
+       if (xscale_debug_handler_size > 0x800) {
+               LOG_ERROR("debug_handler.bin: larger than 2kb");
+               return ERROR_FAIL;
+       }
+
        xscale = calloc(1, sizeof(*xscale));
        if (!xscale)
                return ERROR_FAIL;
index a5d83ee..9d92550 100644 (file)
@@ -170,4 +170,10 @@ enum
 
 #define ERROR_XSCALE_NO_TRACE_DATA     (-1500)
 
+/* This XScale "debug handler" is loaded into the processor's
+ * mini-ICache, which is 2K of code writable only via JTAG.
+ */
+extern const uint8_t xscale_debug_handler[];
+extern const uint32_t xscale_debug_handler_size;
+
 #endif /* XSCALE_H */
diff --git a/src/target/xscale_debug.S b/src/target/xscale_debug.S
new file mode 100644 (file)
index 0000000..0a7b87d
--- /dev/null
@@ -0,0 +1,13 @@
+       .section        .rodata
+
+       .align          4
+       .global          xscale_debug_handler
+xscale_debug_handler:
+       .incbin         "xscale/debug_handler.bin"
+       .size           xscale_debug_handler, . - xscale_debug_handler
+
+       .align          4
+       .global          xscale_debug_handler_size
+xscale_debug_handler_size:
+       .word           . - xscale_debug_handler
+       .size           xscale_debug_handler_size, 4