[coreboot-gerrit] Change in em100[master]: Support 4-byte address mode in SPI traces

[Stefan Reinauer (Code Review)]

Stefan Reinauer has uploaded this change for review. ( https://review.coreboot.org/c/em100/+/48553 )

Change subject: Support 4-byte address mode in SPI traces
......................................................................

Support 4-byte address mode in SPI traces

- Track address mode globally, so we can access the user presets when
  reading SPI traces.
- Enable address mode switching based on the SPI opcodes 0xB7 / 0xE9
- Read additional address byte when appropriate and skip it in the data
  stream
- Skip trace packets without valid data

Signed-off-by: Stefan Reinauer 
Change-Id: Iec9f36356eb7e612a909855cda85dc0ce1b5adc0
---
M em100.c
M em100.h
M trace.c
3 files changed, 23 insertions(+), 5 deletions(-)

git pull ssh://review.coreboot.org:29418/em100 refs/changes/53/48553/1

diff --git a/em100.c b/em100.c
index c4b6c01..ca6e683 100644
--- a/em100.c
+++ b/em100.c
@@ -29,6 +29,7 @@
 TFILE *configs;
 char *database_version;
 int debug = 0;
+int address_mode = 3;

volatile sig_atomic_t exit_requested = 0;
 static struct em100 em100_state;
@@ -835,7 +836,6 @@
    int compatibility = 0;
    int bus = 0, device = 0;
    int firmware_is_dpfw = 0;
-	int address_mode = 0;
    unsigned int serial_number = 0;
    unsigned long address_offset = 0;
    unsigned int spi_start_address = 0;
diff --git a/em100.h b/em100.h
index d49339b..ecb74d2 100644
--- a/em100.h
+++ b/em100.h
@@ -197,6 +197,7 @@
 #define ARRAY_SIZE(a) (sizeof(a) / sizeof((a)[0]))
 char *get_em100_file(const char *name);
 extern int debug;
+extern int address_mode;
 extern volatile sig_atomic_t exit_requested;

/* Chips */
diff --git a/trace.c b/trace.c
index 0c6cdfd..108691b 100644
--- a/trace.c
+++ b/trace.c
@@ -128,6 +128,7 @@
    	{"exit 4-byte address mode",	0xe9,	0,	0},
    	{"enter quad i/o mode",		0x35,	0,	0},
    	{"exit quad i/o mode",		0xf5,	0,	0},
+		{"read SFDP Table",		0x5a,	1,	0},

{"unknown command",		0xff,	0,	0}
 };
@@ -178,6 +179,11 @@
    		unsigned int j = additional_pad_bytes;
    		additional_pad_bytes = 0;
    		unsigned char cmd = data[2 + i*8];
+
+			if (cmd == 0x00) {
+				/* packet without valid data */
+				continue;
+			}
    		if (cmd == 0xff) {
    			/* timestamp */
    			timestamp = data[2 + i*8 + 2];
@@ -201,16 +207,27 @@
    			if (counter == 0)
    				start_timestamp = timestamp;

+                                /* Special commands */
+                                switch (spi_command) {
+                                case 0xb7:
+                                        address_mode = 4;
+                                        break;
+                                case 0xe9:
+                                        address_mode = 3;
+                                        break;
+                                }
+
    			/* set up address if used by this command*/
    			if (!spi_cmd_vals->uses_address) {
    				j = 1; /* skip command byte */
    			} else {
-					address = (data[i * 8 + 5] << 16) +
-							(data[i * 8 + 6] << 8) +
-							data[i * 8 + 7];
+					if (address_mode == 3)
+						address = (data[i * 8 + 5] << 16) + (data[i * 8 + 6] << 8) + data[i * 8 + 7];
+					else
+						address = (data[i * 8 + 5] << 24) + (data[i * 8 + 6] << 16) + (data[i * 8 + 7] << 8) + data[i * 8 + 8];

/* skip command, address bytes, and padding */
-					j = 4 + spi_cmd_vals->pad_bytes;
+					j = 1 + address_mode + spi_cmd_vals->pad_bytes;
    				if (j > MAX_TRACE_BLOCKLENGTH) {
    					additional_pad_bytes = j -
    						MAX_TRACE_BLOCKLENGTH;