From 0d4585b28ffcac1b62ed37cee2c34de0515df468 Mon Sep 17 00:00:00 2001
From: Thomas Martitz <kugel@rockbox.org>
Date: Thu, 9 Sep 2010 16:17:21 +0000
Subject: Extend lc_open() to also being able to load overlay plugins.

For this it needs to look at the plugin header. Since lc_open() doesn't know
it's a plugin, the header needs to be changed slightly to include the new lc_header (which needs to be the first element in plugin_header so it can be casted savely).

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@28054 a1c6a512-1295-4272-9138-f99709370657
---
 firmware/load_code.c | 59 +++++++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 49 insertions(+), 10 deletions(-)

(limited to 'firmware/load_code.c')

diff --git a/firmware/load_code.c b/firmware/load_code.c
index 75bac8b2ac..5b5307e622 100644
--- a/firmware/load_code.c
+++ b/firmware/load_code.c
@@ -26,37 +26,77 @@
 #include "load_code.h"
 
 #if (CONFIG_PLATFORM & PLATFORM_NATIVE)
+
 /* load binary blob from disk to memory, returning a handle */
-void * lc_open(const char *filename, char *buf, size_t buf_size)
+void * lc_open(const char *filename, unsigned char *buf, size_t buf_size)
 {
     int fd = open(filename, O_RDONLY);
     ssize_t read_size;
+    struct lc_header hdr;
+    unsigned char *buf_end = buf+buf_size;
+    off_t copy_size;
 
     if (fd < 0)
     {
         DEBUGF("Could not open file");
-        return NULL;
+        goto error;
     }
 
 #if NUM_CORES > 1
     /* Make sure COP cache is flushed and invalidated before loading */
     {
         int my_core = switch_core(CURRENT_CORE ^ 1);
-        cpucache_invalidate();
+        cpucache_commit_discard();
         switch_core(my_core);
     }
 #endif
 
-    read_size = read(fd, buf, buf_size);
+    /* read the header to obtain the load address */
+    read_size = read(fd, &hdr, sizeof(hdr));
+
+    if (read_size < 0)
+    {
+        DEBUGF("Could not read from file");
+        goto error_fd;
+    }
+
+    /* hdr.end_addr points to the end of the bss section,
+     * but there might be idata/icode behind that so the bytes to copy
+     * can be larger */
+    copy_size = MAX(filesize(fd), hdr.end_addr - hdr.load_addr);
+
+    if (hdr.load_addr < buf || (hdr.load_addr+copy_size) > buf_end)
+    {
+        DEBUGF("Binary doesn't fit into memory");
+        goto error_fd;
+    }
+
+    /* go back to beginning to load the whole thing (incl. header) */
+    if (lseek(fd, 0, SEEK_SET) < 0)
+    {
+        DEBUGF("lseek failed");
+        goto error_fd;
+    }
+
+    /* the header has the addresses where the code is linked at */
+    read_size = read(fd, hdr.load_addr, copy_size);
     close(fd);
-    cpucache_invalidate();
 
     if (read_size < 0)
     {
         DEBUGF("Could not read from file");
-        return NULL;
+        goto error;
     }
-    return buf;
+
+    /* commit dcache and discard icache */
+    cpucache_commit_discard();
+    /* return a pointer the header, reused by lc_get_header() */
+    return hdr.load_addr;
+
+error_fd:
+    close(fd);
+error:
+    return NULL;
 }
 
 #elif (CONFIG_PLATFORM & PLATFORM_HOSTED)
@@ -85,12 +125,11 @@ static inline char *_dlerror(void)
 #include "rbpaths.h"
 #include "general.h"
 
-void * _lc_open(const _lc_open_char *filename, char *buf, size_t buf_size)
+void * _lc_open(const _lc_open_char *filename, unsigned char *buf, size_t buf_size)
 {
     (void)buf;
     (void)buf_size;
-    void* dl_handle = dlopen(filename, RTLD_NOW);
-    return dl_handle;
+    return dlopen(filename, RTLD_NOW);
 }
 
 void *lc_open_from_mem(void *addr, size_t blob_size)
-- 
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