Re: [SeaBIOS] [RFC][PATCH] coreboot: Add support for a "links" file to have aliases in CBFS.

[Kevin O'Connor]

On Thu, Jan 30, 2014 at 12:30:11PM -0500, Kevin O'Connor wrote:
> The "links" file is a newline separated list where each line is a
> "link name" followed by a "destination name" separated by a space
> character.  For each line, SeaBIOS will consider each "link name" to
> be a CBFS file that has the contents found in the CBFS file with
> "destination name".
> Signed-off-by: Kevin O'Connor
>
> This patch may be useful for those using intel option roms where the
> same rom is used on a number of VGA devices with different
> vendor/device ids.  With this patch, one can make a "links" file with
> the list of devices (eg, "pci8086,0a06.rom") that all point to the
> same physical rom (eg, "pci8086,0406.rom").
>
> It's possible to implement this aliasing approach in a number of
> different ways.  The approach taken in this patch is a single file
> with all the link names.  This was done based on feedback that there
> could be 20 or more aliases for a single rom and creating individual
> CBFS files for each link would be unwieldy.
>
> That said, I'm not sure this is the best approach.  I'm circulating it
> for comments.

FYI, below is a version of the patch with a more resilent parser.
Same comments as above.

-Kevin
> From 1e44227576fc76d81bfd3ee5ccb32bca827f17b1 Mon Sep 17 00:00:00 2001

Message-Id: 
From: Kevin O'Connor 
Date: Fri, 17 Jan 2014 12:11:49 -0500
Subject: [PATCH] coreboot: Add support for a "links" file to have aliases in
 CBFS.
To: [e-mail]

The "links" file is a newline separated list where each line is a
"link name" followed by a "destination name" separated by a space
character.  For each line, SeaBIOS will consider each "link name" to
be a CBFS file that has the contents found in the CBFS file with
"destination name".

Signed-off-by: Kevin O'Connor 
---
 src/fw/coreboot.c | 39 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/src/fw/coreboot.c b/src/fw/coreboot.c
index df8fca8..cfb7a70 100644
--- a/src/fw/coreboot.c
+++ b/src/fw/coreboot.c
@@ -408,6 +408,45 @@ coreboot_cbfs_init(void)
         fhdr = (void*)ALIGN((u32)cfile->data + cfile->rawsize
                             , be32_to_cpu(hdr->align));
     }
+
+    // Process CBFS links file.  The links file is a newline separated
+    // file where each line has a "link name" and a "destination name"
+    // separated by a space character.
+    char *links = romfile_loadfile("links", NULL), *next = links;
+    while (next) {
+        // Parse out linkname and destname
+        char *linkname = next;
+        next = strchr(linkname, '\n');
+        if (next)
+            *next++ = '\0';
+        while (*linkname && *linkname <= ' ')
+            linkname++;
+        char *comment = strchr(linkname, '#');
+        if (comment)
+            *comment = '\0';
+        nullTrailingSpace(linkname);
+        char *destname = strchr(linkname, ' ');
+        if (!destname)
+            continue;
+        *destname++ = '\0';
+        while (*destname && *destname <= ' ')
+            destname++;
+        // Lookup destname and create new romfile entry for linkname
+        struct romfile_s *ufile = romfile_find(destname);
+        if (!ufile)
+            continue;
+        struct cbfs_romfile_s *cufile
+            = container_of(ufile, struct cbfs_romfile_s, file);
+        struct cbfs_romfile_s *cfile = malloc_tmp(sizeof(*cfile));
+        if (!cfile) {
+            warn_noalloc();
+            break;
+        }
+        memcpy(cfile, cufile, sizeof(*cfile));
+        strtcpy(cfile->file.name, linkname, sizeof(cfile->file.name));
+        romfile_add(&cfile->file);
+    }
+    free(links);
 }

struct cbfs_payload_segment {