+/*
+ * Copyright © 2013 Keith Packard <keithp@keithp.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ */
+
+#include "ao-elf.h"
+#include <err.h>
+#include <gelf.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include "ccdbg.h"
+#include "ao-stmload.h"
+
+/*
+ * Look through the Elf file for the AltOS symbols
+ * that can be adjusted before the image is written
+ * to the device
+ */
+static int
+find_symbols (Elf *e)
+{
+ Elf_Scn *scn;
+ Elf_Data *symbol_data = NULL;
+ GElf_Shdr shdr;
+ GElf_Sym sym;
+ int i, symbol_count, s;
+ int required = 0;
+ char *symbol_name;
+ char *section_name;
+ size_t shstrndx;
+
+ if (elf_getshdrstrndx(e, &shstrndx) < 0)
+ return 0;
+
+ /*
+ * Find the symbols
+ */
+
+ scn = NULL;
+ while ((scn = elf_nextscn(e, scn)) != NULL) {
+
+ if (gelf_getshdr(scn, &shdr) != &shdr)
+ return 0;
+
+ if (shdr.sh_type == SHT_SYMTAB) {
+ symbol_data = elf_getdata(scn, NULL);
+ symbol_count = shdr.sh_size / shdr.sh_entsize;
+ break;
+ }
+ }
+
+ if (!symbol_data)
+ return 0;
+
+ for (i = 0; i < symbol_count; i++) {
+ gelf_getsym(symbol_data, i, &sym);
+
+ symbol_name = elf_strptr(e, shdr.sh_link, sym.st_name);
+
+ for (s = 0; s < ao_num_symbols; s++)
+ if (!strcmp (ao_symbols[s].name, symbol_name)) {
+ int t;
+ ao_symbols[s].addr = sym.st_value;
+ if (ao_symbols[s].required)
+ ++required;
+ }
+ }
+
+ return required >= ao_num_required_symbols;
+}
+
+uint32_t round4(uint32_t a) {
+ return (a + 3) & ~3;
+}
+
+struct hex_image *
+new_load (uint32_t addr, uint32_t len)
+{
+ struct hex_image *new;
+
+ len = round4(len);
+ new = calloc (1, sizeof (struct hex_image) + len);
+ if (!new)
+ abort();
+
+ new->address = addr;
+ new->length = len;
+ return new;
+}
+
+void
+load_paste(struct hex_image *into, struct hex_image *from)
+{
+ if (from->address < into->address || into->address + into->length < from->address + from->length)
+ abort();
+
+ memcpy(into->data + from->address - into->address, from->data, from->length);
+}
+
+/*
+ * Make a new load structure large enough to hold the old one and
+ * the new data
+ */
+struct hex_image *
+expand_load(struct hex_image *from, uint32_t address, uint32_t length)
+{
+ struct hex_image *new;
+
+ if (from) {
+ uint32_t from_last = from->address + from->length;
+ uint32_t last = address + length;
+
+ if (address > from->address)
+ address = from->address;
+ if (last < from_last)
+ last = from_last;
+
+ length = last - address;
+
+ if (address == from->address && length == from->length)
+ return from;
+ }
+ new = new_load(address, length);
+ if (from) {
+ load_paste(new, from);
+ free (from);
+ }
+ return new;
+}
+
+/*
+ * Create a new load structure with data from the existing one
+ * and the new data
+ */
+struct hex_image *
+load_write(struct hex_image *from, uint32_t address, uint32_t length, void *data)
+{
+ struct hex_image *new;
+
+ new = expand_load(from, address, length);
+ memcpy(new->data + address - new->address, data, length);
+ return new;
+}
+
+/*
+ * Construct a large in-memory block for all
+ * of the loaded sections of the program
+ */
+static struct hex_image *
+get_load(Elf *e)
+{
+ Elf_Scn *scn;
+ size_t shstrndx;
+ GElf_Shdr shdr;
+ Elf_Data *data;
+ char *got_name;
+ size_t nphdr;
+ size_t p;
+ GElf_Phdr phdr;
+ GElf_Addr p_paddr;
+ GElf_Off p_offset;
+ GElf_Addr sh_paddr;
+ struct hex_image *load = NULL;
+ char *section_name;
+ size_t nshdr;
+ size_t s;
+
+ if (elf_getshdrstrndx(e, &shstrndx) < 0)
+ return 0;
+
+ if (elf_getphdrnum(e, &nphdr) < 0)
+ return 0;
+
+ if (elf_getshdrnum(e, &nshdr) < 0)
+ return 0;
+
+ /*
+ * As far as I can tell, all of the phdr sections should
+ * be flashed to memory
+ */
+ for (p = 0; p < nphdr; p++) {
+
+ /* Find this phdr */
+ gelf_getphdr(e, p, &phdr);
+
+ if (phdr.p_type != PT_LOAD)
+ continue;
+
+ p_offset = phdr.p_offset;
+ /* Get the associated file section */
+
+#if 0
+ printf ("offset %08x vaddr %08x paddr %08x filesz %08x memsz %08x\n",
+ (uint32_t) phdr.p_offset,
+ (uint32_t) phdr.p_vaddr,
+ (uint32_t) phdr.p_paddr,
+ (uint32_t) phdr.p_filesz,
+ (uint32_t) phdr.p_memsz);
+#endif
+
+ for (s = 0; s < nshdr; s++) {
+ scn = elf_getscn(e, s);
+
+ if (!scn) {
+ printf ("getscn failed\n");
+ abort();
+ }
+ if (gelf_getshdr(scn, &shdr) != &shdr) {
+ printf ("gelf_getshdr failed\n");
+ abort();
+ }
+
+ section_name = elf_strptr(e, shstrndx, shdr.sh_name);
+
+ if (phdr.p_offset <= shdr.sh_offset && shdr.sh_offset < phdr.p_offset + phdr.p_filesz) {
+
+ if (shdr.sh_size == 0)
+ continue;
+
+ sh_paddr = phdr.p_paddr + shdr.sh_offset - phdr.p_offset;
+
+ printf ("\tsize %08x rom %08x exec %08x %s\n",
+ (uint32_t) shdr.sh_size,
+ (uint32_t) sh_paddr,
+ (uint32_t) shdr.sh_addr,
+ section_name);
+
+ data = elf_getdata(scn, NULL);
+
+ /* Write the section data into the memory block */
+ load = load_write(load, sh_paddr, shdr.sh_size, data->d_buf);
+ }
+ }
+ }
+ return load;
+}
+
+/*
+ * Open the specified ELF file and
+ * check for the symbols we need
+ */
+
+struct hex_image *
+ao_load_elf(char *name)
+{
+ int fd;
+ Elf *e;
+ Elf_Scn *scn;
+ Elf_Data *symbol_data = NULL;
+ GElf_Shdr shdr;
+ GElf_Sym sym;
+ size_t n, shstrndx, sz;
+ int i, symbol_count, s;
+ int required = 0;
+ struct hex_image *image;
+
+ if (elf_version(EV_CURRENT) == EV_NONE)
+ return NULL;
+
+ fd = open(name, O_RDONLY, 0);
+
+ if (fd < 0)
+ return NULL;
+
+ e = elf_begin(fd, ELF_C_READ, NULL);
+
+ if (!e)
+ return NULL;
+
+ if (elf_kind(e) != ELF_K_ELF)
+ return NULL;
+
+ if (elf_getshdrstrndx(e, &shstrndx) != 0)
+ return NULL;
+
+ if (!find_symbols(e)) {
+ fprintf (stderr, "Cannot find required symbols\n");
+ return NULL;
+ }
+
+ image = get_load(e);
+ if (!image) {
+ fprintf (stderr, "Cannot create memory image from file\n");
+ return NULL;
+ }
+
+ return image;
+}