[OpenBIOS] [PATCH v2 2/3] fw_cfg: add fw_cfg_find_file() and fw_cfg_read_file() functions

[Mark Cave-Ayland]

These allow OpenBIOS to locate fw_cfg files by name and then read
them via the fw_cfg interface.

Signed-off-by: Mark Cave-Ayland 
---
 drivers/fw_cfg.c             |   42 ++++++++++++++++++++++++++++++++++++++++++
 include/arch/common/fw_cfg.h |   15 +++++++++++++++
 2 files changed, 57 insertions(+)

diff --git a/drivers/fw_cfg.c b/drivers/fw_cfg.c
index 7086873..a95538a 100644
--- a/drivers/fw_cfg.c
+++ b/drivers/fw_cfg.c
@@ -73,6 +73,48 @@ fw_cfg_read_i16(uint16_t cmd)
     return __le16_to_cpu(buf);
 }

+uint32_t
+fw_cfg_find_file(const char *filename, uint16_t *select, uint32_t *size)
+{
+    FWCfgFile f;
+    unsigned int i;
+    uint32_t buf, count;
+
+    /* Unusually all FW_CFG_FILE_DIR fields are BE */
+    fw_cfg_read(FW_CFG_FILE_DIR, (char *)&buf, sizeof(uint32_t));
+    count = __be32_to_cpu(buf);
+
+    for (i = 0; i < count; i++) {
+        fw_cfg_read_bytes((char *)&f, sizeof(f));
+
+        if (!strcmp(f.name, filename)) {
+            *select = __be16_to_cpu(f.select);
+            *size = __be32_to_cpu(f.size);
+
+            return -1;
+        }
+    }
+
+    return 0;
+}
+
+char *
+fw_cfg_read_file(const char *filename, uint32_t *size)
+{
+    uint16_t cmd;
+    uint32_t nbytes;
+    char *buf;
+
+    if (fw_cfg_find_file(filename, &cmd, &nbytes)) {
+        buf = malloc(nbytes);
+        fw_cfg_read(cmd, buf, nbytes);
+        *size = nbytes;
+        return buf;
+    }
+
+    return NULL;
+}
+
 void
 fw_cfg_init(void)
 {
diff --git a/include/arch/common/fw_cfg.h b/include/arch/common/fw_cfg.h
index df44c2e..1c43a9d 100644
--- a/include/arch/common/fw_cfg.h
+++ b/include/arch/common/fw_cfg.h
@@ -85,6 +85,21 @@ uint64_t fw_cfg_read_i64(uint16_t cmd);
 uint32_t fw_cfg_read_i32(uint16_t cmd);
 uint16_t fw_cfg_read_i16(uint16_t cmd);
 void fw_cfg_init(void);
+
+typedef struct FWCfgFile {
+    uint32_t  size;        /* file size */
+    uint16_t  select;      /* write this to 0x510 to read it */
+    uint16_t  reserved;
+    char      name[56];
+} FWCfgFile;
+
+typedef struct FWCfgFiles {
+    uint32_t  count;
+    FWCfgFile f[];
+} FWCfgFiles;
+
+unsigned int fw_cfg_find_file(const char *filename, uint16_t *select, uint32_t *size);
+char *fw_cfg_read_file(const char *filename, uint32_t *size);
 #endif /* NO_OPENBIOS_PROTOS */

#endif