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

[Werner Zeh (Code Review)]

Werner Zeh has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/36017 )

Change subject: x86 gdb: Extend GDB stub with MSR read and write commands
......................................................................

x86 gdb: Extend GDB stub with MSR read and write commands

Add commands to read and write MSRs on x86.

NOT FOR MERGE!!!

Change-Id: I4addf44305dbcfb06c7573dc30541038356f2c33
Signed-off-by: Werner Zeh 
---
M src/arch/x86/exception.c
1 file changed, 33 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/17/36017/1

diff --git a/src/arch/x86/exception.c b/src/arch/x86/exception.c
index c2783d5..7d10c3e 100644
--- a/src/arch/x86/exception.c
+++ b/src/arch/x86/exception.c
@@ -22,6 +22,7 @@
 #include <stdint.h>
 #include <string.h>
 #include <arch/io.h>
+#include <cpu/x86/msr.h>

#if CONFIG(GDB_STUB)

@@ -417,6 +418,7 @@
    while (1) {
    	unsigned long addr, length, val;
    	char *ptr;
+		msr_t msr;
    	out_buffer[0] = '\0';
    	out_buffer[1] = '\0';
    	if (!get_packet(in_buffer))
@@ -428,6 +430,37 @@
    		out_buffer[2] = hexchars[signo & 0xf];
    		out_buffer[3] = '\0';
    		break;
+		case 'e':
+			/* eAA..AA: Read MSR given by AA..AA. */
+			ptr = &in_buffer[1];
+			if (parse_ulong(&ptr, &addr) &&
+			    (*(ptr++) == ':')) {
+				char *out_buf_ptr = out_buffer;
+
+				msr = rdmsr(addr);
+				copy_to_hex(out_buf_ptr, (void *)&(msr.hi), 4);
+				out_buf_ptr += (4 << 1);
+				copy_to_hex(out_buf_ptr, (void *)&(msr.lo), 4);
+			} else
+				memcpy(out_buffer, "E05", 4);
+			break;
+		case 'E':
+			/* EAA..AA,HHHH,LLLL: Write MSR given by AA..AA. */
+			/* Put HHHH into high portion of the 64 bit */
+			/* and LLLL into the low portion. */
+			ptr = &in_buffer[1];
+			if (parse_ulong(&ptr, &addr) &&
+				(*(ptr++) == ',') &&
+				parse_ulong(&ptr, (unsigned long *) &msr.hi) &&
+				(*(ptr++) == ',') &&
+				parse_ulong(&ptr, (unsigned long *) &msr.lo) &&
+				(*(ptr++) == ':')) {
+				wrmsr(addr, msr);
+				memcpy(out_buffer, "OK", 3);
+			} else
+				memcpy(out_buffer, "E06", 4);
+			break;
+
    	case 'g': /* return the value of the CPU registers */
    		copy_to_hex(out_buffer, &gdb_stub_registers,
    			sizeof(gdb_stub_registers));