[coreboot-gerrit] Change in coreboot[master]: x86 gdb: Extend GDB stub with I/O read and write commands

[Werner Zeh (Code Review)]

Werner Zeh has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/36016 )

Change subject: x86 gdb: Extend GDB stub with I/O read and write commands
......................................................................

x86 gdb: Extend GDB stub with I/O read and write commands

Provide functionality in the GDB stub to read and write I/O ports on x86
CPUs.

NOT FOR MERGE!!!

Change-Id: I8718c576bba149475444947b6cc3d4932547e6eb
Signed-off-by: Werner Zeh 
---
M src/arch/x86/exception.c
1 file changed, 86 insertions(+), 1 deletion(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/16/36016/1

diff --git a/src/arch/x86/exception.c b/src/arch/x86/exception.c
index b88f4a7..c2783d5 100644
--- a/src/arch/x86/exception.c
+++ b/src/arch/x86/exception.c
@@ -21,6 +21,7 @@
 #include <cpu/x86/lapic.h>
 #include <stdint.h>
 #include <string.h>
+#include <arch/io.h>

#if CONFIG(GDB_STUB)

@@ -335,6 +336,8 @@
    	/* now, read until a # or end of buffer is found */
    	while (count < BUFMAX) {
    		ch = stub_getc() & 0x7f;
+			if (!ch)
+				continue;
    		if (ch == '#')
    			break;
    		checksum = checksum + ch;
@@ -412,7 +415,7 @@
    put_packet(out_buffer);

while (1) {
-		unsigned long addr, length;
+		unsigned long addr, length, val;
    	char *ptr;
    	out_buffer[0] = '\0';
    	out_buffer[1] = '\0';
@@ -462,6 +465,88 @@
    		} else
    			memcpy(out_buffer, "E02", 4);
    		break;
+		case 'n':
+			/* nAA..AA,LLLL,w Read I/O port given by AA..AA. */
+			/* Use access width defined with w (b:byte, w:word,
+			 * l:long) and read LLLL number of entries */
+			ptr = &in_buffer[1];
+			if (parse_ulong(&ptr, &addr) &&
+				(*(ptr++) == ',') &&
+				parse_ulong(&ptr, &length) &&
+				(*(ptr++) == ',') &&
+				((*(ptr) == 'b') || (*(ptr) == 'w') ||
+				 (*(ptr) == 'l'))) {
+				char width = *(ptr++), len;
+				char *out_buf_ptr = out_buffer;
+				unsigned long i, tmp;
+				/* Read desired amount of I/O ports */
+				for (i = 0; i < length; i++) {
+					switch (width) {
+					case 'l':
+						tmp = inl(addr);
+						/* Rotate the byte order as */
+						/* copy_to_hex() works on a */
+						/* byte stream. */
+						val = (((tmp >> 24) & 0xff) |
+						(((tmp >> 16) & 0xff) << 8) |
+						(((tmp >> 8) & 0xff) << 16) |
+						((tmp & 0xff) << 24));
+						len = 4;
+						break;
+					case 'w':
+						tmp = inw(addr);
+						/* Rotate the byte order as */
+						/* copy_to_hex() works on a */
+						/* byte stream. */
+						val = (((tmp >> 8) & 0xff) |
+						((tmp & 0xff) << 8));
+						len = 2;
+						break;
+					case 'b':
+					default:
+						val = inb(addr);
+						len = 1;
+						break;
+
+					}
+					copy_to_hex(out_buf_ptr, (void *)&val,
+									len);
+					out_buf_ptr += len << 1;
+					addr += len;
+				}
+			} else
+				memcpy(out_buffer, "E03", 4);
+			break;
+		case 'N':
+			/* nAA..AA,VVVV,w: Write I/O port given by AA..AA. */
+			/* Use access width defined with w (b:byte, w:word,
+			 * l:long) and write value given by VVVV. */
+			ptr = &in_buffer[1];
+			if (parse_ulong(&ptr, &addr) &&
+			 (*(ptr++) == ',') &&
+			 parse_ulong(&ptr, &val) &&
+			 (*(ptr++) == ',') &&
+			 ((*(ptr) == 'b') || (*(ptr) == 'w') ||
+			  (*(ptr) == 'l')) &&
+			 (*(++ptr) == ':')) {
+				char width = *(ptr - 1);
+
+				switch (width) {
+				case 'l':
+					outl(val,  addr);
+					break;
+				case 'w':
+					outw(val,  addr);
+					break;
+				case 'b':
+				default:
+					outb(val,  addr);
+					break;
+				}
+				memcpy(out_buffer, "OK", 3);
+			} else
+				memcpy(out_buffer, "E04", 4);
+			break;
    	case 's':
    	case 'c':
    		/* cAA..AA    Continue at address AA..AA(optional)