New patch to review for coreboot: 8c20643 libpayload: allow for pointers in cbfs ram media

[Stefan Reinauer]

Stefan Reinauer ([e-mail]) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/4193

-gerrit

commit 8c20643d47864d9e5c2013d5f236ec6f22e7734e
Author: Aaron Durbin 
Date:   Fri May 24 13:34:38 2013 -0500

libpayload: allow for pointers in cbfs ram media

The ram_map() handled offsets from 0->size as well as
    negative offsets from the top of the region. However,
    the cbfs core tries to map a offset that is actually a
    pointer within the region itself. Allow for such instances.
    This fixes an issue when using ram_media with tthe ebmedded
    SeaBIOS cbfs.

Change-Id: I15b0b3b643390d3784ae5887c0f17d420d59c5b6
    Signed-off-by: Aaron Durbin 
    Reviewed-on: https://gerrit.chromium.org/gerrit/56641
    Reviewed-by: Duncan Laurie 
    Reviewed-by: Stefan Reinauer 
---
 payloads/libpayload/libcbfs/ram_media.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/payloads/libpayload/libcbfs/ram_media.c b/payloads/libpayload/libcbfs/ram_media.c
index 859555c..9f11a31 100644
--- a/payloads/libpayload/libcbfs/ram_media.c
+++ b/payloads/libpayload/libcbfs/ram_media.c
@@ -43,6 +43,12 @@ static int ram_open(struct cbfs_media *media) {

static void *ram_map(struct cbfs_media *media, size_t offset, size_t count) {
    struct ram_media *m = (struct ram_media*)media->context;
+
+	/* Special case an absolute pointer within the region. */
+	if (offset >= (uintptr_t)m->start &&
+	    offset < ((uintptr_t)m->start + m->size))
+		return (void *)offset;
+
    /* assume addressing from top of image in this case */
    if (offset > 0xf0000000) {
    	offset = m->size + offset;