fw_cfg: add API for file transfer.

This patch adds a file transfer interface to fw_cfg.  Intended to be
used for passing non-pci option roms and vgabios to seabios.  Namespace
is modeled after the existing cbfs filesystem support in seabios.

Reading the new FW_CFG_FILE_DIR entry returns a file list.
Fields there are in network byte order (aka bigendian).

aliguori: fix fw_cfg.h for multiboot.bin, add proper fw_cfg.h declarations,
          quiet fprintf() in fw_cfg.c

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

hw/fw_cfg.c

@@ -47,6 +47,7 @@ typedef struct _FWCfgEntry {
 
 struct _FWCfgState {
     FWCfgEntry entries[2][FW_CFG_MAX_ENTRY];
+    FWCfgFiles *files;
     uint16_t cur_entry;
     uint32_t cur_offset;
 };
@@ -273,6 +274,48 @@ int fw_cfg_add_callback(FWCfgState *s, uint16_t key, FWCfgCallback callback,
     return 1;
 }
 
+int fw_cfg_add_file(FWCfgState *s,  const char *dir, const char *filename,
+                    uint8_t *data, uint32_t len)
+{
+    const char *basename;
+    int index;
+
+    if (!s->files) {
+        int dsize = sizeof(uint32_t) + sizeof(FWCfgFile) * FW_CFG_FILE_SLOTS;
+        s->files = qemu_mallocz(dsize);
+        fw_cfg_add_bytes(s, FW_CFG_FILE_DIR, (uint8_t*)s->files, dsize);
+    }
+
+    index = be32_to_cpu(s->files->count);
+    if (index == FW_CFG_FILE_SLOTS) {
+        fprintf(stderr, "fw_cfg: out of file slots\n");
+        return 0;
+    }
+
+    fw_cfg_add_bytes(s, FW_CFG_FILE_FIRST + index, data, len);
+
+    basename = strrchr(filename, '/');
+    if (basename) {
+        basename++;
+    } else {
+        basename = filename;
+    }
+    if (dir) {
+        snprintf(s->files->f[index].name, sizeof(s->files->f[index].name),
+                 "%s/%s", dir, basename);
+    } else {
+        snprintf(s->files->f[index].name, sizeof(s->files->f[index].name),
+                 "%s", basename);
+    }
+    s->files->f[index].size   = cpu_to_be32(len);
+    s->files->f[index].select = cpu_to_be16(FW_CFG_FILE_FIRST + index);
+    FW_CFG_DPRINTF("%s: #%d: %s (%d bytes)\n", __FUNCTION__,
+                   index, s->files->f[index].name, len);
+
+    s->files->count = cpu_to_be32(index+1);
+    return 1;
+}
+
 FWCfgState *fw_cfg_init(uint32_t ctl_port, uint32_t data_port,
                         target_phys_addr_t ctl_addr, target_phys_addr_t data_addr)
 {

hw/fw_cfg.h

@@ -26,7 +26,11 @@
 #define FW_CFG_SETUP_ADDR       0x16
 #define FW_CFG_SETUP_SIZE       0x17
 #define FW_CFG_SETUP_DATA       0x18
-#define FW_CFG_MAX_ENTRY        0x19
+#define FW_CFG_FILE_DIR         0x19
+
+#define FW_CFG_FILE_FIRST       0x20
+#define FW_CFG_FILE_SLOTS       0x10
+#define FW_CFG_MAX_ENTRY        (FW_CFG_FILE_FIRST+FW_CFG_FILE_SLOTS)
 
 #define FW_CFG_WRITE_CHANNEL    0x4000
 #define FW_CFG_ARCH_LOCAL       0x8000
@@ -35,6 +39,18 @@
 #define FW_CFG_INVALID          0xffff
 
 #ifndef NO_QEMU_PROTOS
+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;
+
 typedef void (*FWCfgCallback)(void *opaque, uint8_t *data);
 
 typedef struct _FWCfgState FWCfgState;
@@ -44,7 +60,8 @@ int fw_cfg_add_i32(FWCfgState *s, uint16_t key, uint32_t value);
 int fw_cfg_add_i64(FWCfgState *s, uint16_t key, uint64_t value);
 int fw_cfg_add_callback(FWCfgState *s, uint16_t key, FWCfgCallback callback,
                         void *callback_opaque, uint8_t *data, size_t len);
-int fw_cfg_add_file(FWCfgState *s, uint8_t type, uint8_t *data, uint32_t len);
+int fw_cfg_add_file(FWCfgState *s, const char *dir, const char *filename,
+                    uint8_t *data, uint32_t len);
 FWCfgState *fw_cfg_init(uint32_t ctl_port, uint32_t data_port,
                         target_phys_addr_t crl_addr, target_phys_addr_t data_addr);