David Claffey <dnclaffey@gmail.com>:

This patch helps fix MIPS big endian (elf32-tradbigmips) targets.
If "-endian big" is not set in target create, the endianess defaults to
little.  mw and md commands will still work, but binary file loads will
have the incorrect word order loaded into memory.

The EJTAG processor access data register (PrAcc) is little endian
regardless of the CPU endianness; it is always loaded LSB first. This
is confirmed by the fact that mips_ejtag_drscan_32() uses buf_set_u32()
to load the scan field; buf_set_u32() is a little-endian formatter. For
big endian targets, data buffers have to be modified so the LSB of each
u32 or u16 is at the lower (first) memory location.  If the drscan
out_value word order is set using buf_set_u32() then it makes sense to
also fixup the in_value with buf_get_u32(); a symmetry argument. This
has no affect on little endian hosts.


git-svn-id: svn://svn.berlios.de/openocd/trunk@2219 b42882b7-edfa-0310-969c-e2dbd0fdcd60

1 files changed, 4 insertions, 2 deletions

diff --git a/src/target/mips_ejtag.c b/src/target/mips_ejtag.c
index 2394b00c..4c8010b5 100644
--- a/src/target/mips_ejtag.c
+++ b/src/target/mips_ejtag.c
@@ -118,7 +118,7 @@ int mips_ejtag_drscan_32(mips_ejtag_t *ejtag_info, u32 *data)
 	if (tap==NULL)
 		return ERROR_FAIL;
 	scan_field_t field;
-	u8 t[4];
+	u8 t[4], r[4];
 	int retval;
 
 	field.tap = tap;
@@ -126,7 +126,7 @@ int mips_ejtag_drscan_32(mips_ejtag_t *ejtag_info, u32 *data)
 	field.out_value = t;
 	buf_set_u32(field.out_value, 0, field.num_bits, *data);
 
-	field.in_value = (u8*)data;
+	field.in_value = r;
 	
 	
 	
@@ -139,6 +139,8 @@ int mips_ejtag_drscan_32(mips_ejtag_t *ejtag_info, u32 *data)
 		return retval;
 	}
 
+	*data = buf_get_u32(field.in_value, 0, 32);
+
 	keep_alive();
 
 	return ERROR_OK;