ELF: allow using program headers and physical addresses to build the image

src/bif.c

@@ -332,6 +332,7 @@ static error bif_parse_file(lexer_t *lex, bif_cfg_t *cfg, bif_node_t *node) {
   node->load = 0;
   node->offset = 0;
   node->bootloader = 0;
+  node->elf_use_ph = 0;
   node->fsbl_config = 0;
   node->pmufw_image = 0;
   node->exception_level = BOOTROM_PART_ATTR_EXC_LVL_EL0;
@@ -462,6 +463,11 @@ error bif_node_set_attr(
     return SUCCESS;
   }
 
+  if (strcmp(attr_name, "elf_use_ph") == 0) {
+    node->elf_use_ph = 0xFF;
+    return SUCCESS;
+  }
+
   if (strcmp(attr_name, "partition_owner") == 0) {
     if (!value) {
       perrorf(lex, "the \"%s\" attribute requires an argument\n", attr_name);

src/bif.h

@@ -40,6 +40,7 @@ typedef struct bif_node_t {
   uint32_t load;
   uint32_t offset;
   uint32_t partition_owner;
+  uint8_t elf_use_ph;  /* boolean */
 
   /* supported zynqmp attributes */
   uint8_t fsbl_config; /* boolean */

src/bootrom.c

@@ -187,7 +187,8 @@ error append_file_to_image(uint32_t *addr,
                      img_size,
                      &elf_nbits,
                      &elf_load,
-                     &elf_entry);
+                     &elf_entry,
+                     node.elf_use_ph);
     if (err) {
       errorf("ELF file reading failed\n");
 
@@ -372,7 +373,8 @@ error create_boot_image(uint32_t *img_ptr,
                        &pmufw_img_size,
                        &pmufw_img_nbits,
                        &pmufw_img_load,
-                       &pmufw_img_entry);
+                       &pmufw_img_entry,
+                       bif_cfg->nodes[i].elf_use_ph);
       if (err) {
         errorf("failed to parse ELF file: %s\n", bif_cfg->nodes[i].fname);
         return ERROR_BOOTROM_ELF;

src/file/elf.c

@@ -34,11 +34,73 @@
 #include <gelf.h>
 #include <unistd.h>
 
+static error elf_create_image_from_ph(Elf *elf, uint32_t start_addr, uint8_t *out_buf) {
+  size_t n_phdrs;
+
+  if(elf_getphdrnum(elf, &n_phdrs) != 0) {
+    printf("elf_getphdrnum failed\n");
+    return ERROR_BOOTROM_ELF;
+  }
+  size_t file_size;
+  uint8_t *raw_data = elf_rawfile(elf, &file_size);
+  if (raw_data == NULL) {
+    return ERROR_BOOTROM_ELF;
+  }
+  for (size_t i = 0; i < n_phdrs; ++i) {
+    GElf_Phdr phdr;
+    if (gelf_getphdr(elf, i, &phdr) == NULL) {
+      printf("gelf_getphdr returned no address\n");
+      continue;
+    }
+    if (phdr.p_type == PT_LOAD) {
+      if (phdr.p_offset + phdr.p_filesz > file_size) {
+        return ERROR_BOOTROM_ELF;
+      }
+      if (phdr.p_filesz > 0) {
+        uint8_t *segment_data = raw_data + phdr.p_offset;
+        size_t segment_size = phdr.p_filesz;
+
+        memcpy(out_buf + phdr.p_paddr - start_addr,
+             segment_data,
+             segment_size);
+      }
+    }
+  }
+  return SUCCESS;
+}
+
 static bool elf_is_loadable_section(const GElf_Shdr *elf_shdr) {
   return elf_shdr->sh_type != SHT_NOBITS && (elf_shdr->sh_flags & SHF_ALLOC) &&
          elf_shdr->sh_size != 0;
 }
 
+static error elf_get_startaddr_endaddr_from_ph(Elf *elf, uint32_t *start_addr, uint32_t *end_addr) {
+  size_t n_phdrs;
+  *start_addr = -1;
+  *end_addr = 0;
+
+  if (elf_getphdrnum(elf, &n_phdrs) != 0) {
+      return ERROR_BOOTROM_ELF;
+  }
+
+  for (size_t i = 0; i < n_phdrs; ++i) {
+    GElf_Phdr phdr;
+    if (gelf_getphdr(elf, i, &phdr) == NULL) {
+      continue;
+    }
+    if (phdr.p_type == PT_LOAD) {
+      if (*start_addr > phdr.p_paddr) {
+        *start_addr = phdr.p_paddr;
+      }
+
+      if (phdr.p_paddr + phdr.p_filesz > *end_addr) {
+        *end_addr = phdr.p_paddr + phdr.p_filesz;
+      }
+    }
+  }
+  return SUCCESS;
+}
+
 static error elf_get_startaddr_endaddr(Elf *elf, uint32_t *start_addr, uint32_t *end_addr) {
   Elf_Scn *elf_scn = NULL;
   GElf_Shdr elf_shdr;
@@ -95,7 +157,8 @@ error elf_append(void *addr,
                  uint32_t *img_size,
                  uint8_t *elf_nbits,
                  uint32_t *elf_load,
-                 uint32_t *elf_entry) {
+                 uint32_t *elf_entry,
+                 uint8_t elf_use_ph) {
   error err;
   int fd_elf;
   Elf *elf;
@@ -124,10 +187,18 @@ error elf_append(void *addr,
     return ERROR_BOOTROM_ELF;
   }
 
-  if ((err = elf_get_startaddr_endaddr(elf, &start_addr, &end_addr))) {
-    elf_end(elf);
-    close(fd_elf);
-    return err;
+  if (elf_use_ph) {
+    if ((err = elf_get_startaddr_endaddr_from_ph(elf, &start_addr, &end_addr))) {
+      elf_end(elf);
+      close(fd_elf);
+      return err;
+    }
+  } else {
+    if ((err = elf_get_startaddr_endaddr(elf, &start_addr, &end_addr))) {
+      elf_end(elf);
+      close(fd_elf);
+      return err;
+    }
   }
 
   if (end_addr - start_addr > img_max_size) {
@@ -138,10 +209,18 @@ error elf_append(void *addr,
 
   memset(addr, 0, end_addr - start_addr);
 
-  if ((err = elf_create_image(elf, start_addr, addr))) {
-    elf_end(elf);
-    close(fd_elf);
-    return err;
+  if (elf_use_ph) {
+    if ((err = elf_create_image_from_ph(elf, start_addr, addr))) {
+      elf_end(elf);
+      close(fd_elf);
+      return err;
+    }
+  } else {
+    if ((err = elf_create_image(elf, start_addr, addr))) {
+      elf_end(elf);
+      close(fd_elf);
+      return err;
+    }
   }
 
   if (gelf_getehdr(elf, &elf_ehdr) != &elf_ehdr) {
@@ -159,4 +238,4 @@ error elf_append(void *addr,
   close(fd_elf);
 
   return SUCCESS;
-}
+}

src/file/elf.h

@@ -9,6 +9,7 @@ error elf_append(void *addr,
                  uint32_t *img_size,
                  uint8_t *elf_nbits,
                  uint32_t *elf_load,
-                 uint32_t *elf_entry);
+                 uint32_t *elf_entry,
+                 uint8_t elf_use_ph);
 
 #endif