improved elf loading

2 files changed, 51 insertions, 15 deletions

diff --git a/source/elf_load.cpp b/source/elf_load.cpp
index 8149e8a..161bd7e 100644
--- a/source/elf_load.cpp
+++ b/source/elf_load.cpp
@@ -54,29 +54,25 @@ entry_t load(void *elf_data, void *elf_load_offset)
     //                  [elf_load_offset](auto func) { (func + elf_load_offset)(); });
     //}
 
-    // Find filter code start
-    if (auto filter = find_section(ehdr, ".process_data"); filter)
-        return ptr_from_offset<entry_t>(elf_load_offset, filter->sh_addr | 1); // OR 1 to enable thumb
-    else
-        return nullptr;
+    return ptr_from_offset<entry_t>(elf_load_offset, ehdr->e_entry);
 }
 
 } // namespace elf
 
 Elf32_Shdr *find_section(Elf32_Ehdr *ehdr, const char *name)
 {
-	auto shdr = ptr_from_offset<Elf32_Shdr *>(ehdr, ehdr->e_shoff);
-	auto shdr_str = ptr_from_offset<Elf32_Shdr *>(ehdr,
+    auto shdr = ptr_from_offset<Elf32_Shdr *>(ehdr, ehdr->e_shoff);
+    auto shdr_str = ptr_from_offset<Elf32_Shdr *>(ehdr,
         ehdr->e_shoff + ehdr->e_shstrndx * ehdr->e_shentsize);
 
-	for (Elf32_Half i = 0; i < ehdr->e_shnum; i++) {
-		char *section = ptr_from_offset<char *>(ehdr, shdr_str->sh_offset) + shdr->sh_name;
-		if (!strcmp(section, name))
-			return shdr;
+    for (Elf32_Half i = 0; i < ehdr->e_shnum; i++) {
+        char *section = ptr_from_offset<char *>(ehdr, shdr_str->sh_offset) + shdr->sh_name;
+        if (!strcmp(section, name))
+            return shdr;
 
-		shdr = ptr_from_offset<Elf32_Shdr *>(shdr, ehdr->e_shentsize);
-	}
+        shdr = ptr_from_offset<Elf32_Shdr *>(shdr, ehdr->e_shentsize);
+    }
 
-	return 0;
+    return 0;
 }
 
diff --git a/source/main.cpp b/source/main.cpp
index 6c418ce..4bdd5a2 100644
--- a/source/main.cpp
+++ b/source/main.cpp
@@ -111,12 +111,52 @@ int main()
 	}
 }
 
+void quick_freeall();
+
 void signal_operate(adcsample_t *buffer, size_t count)
 {
-    if (elf_entry)
+    if (elf_entry) {
         elf_entry(buffer, count);
+        quick_freeall();
+    }
+
     auto dac_buffer = &dac_samples[buffer == &adc_samples[0] ? 0 : 1024];
     std::copy(buffer, buffer + count, dac_buffer);
     signal_operate_done = buffer == &adc_samples[1024];
 }
 
+// Dynamic memory allocation below
+
+uint8_t quick_malloc_heap[8192];
+uint8_t *quick_malloc_next = quick_malloc_heap;
+
+void *quick_malloc(unsigned int size)
+{
+    if (auto free = std::distance(quick_malloc_next, quick_malloc_heap + 8192); free < 0 || size > static_cast<unsigned int>(free))
+        return nullptr;
+
+    auto ptr = quick_malloc_next;
+    quick_malloc_next += size;
+    return ptr;
+}
+
+void quick_freeall()
+{
+    if (quick_malloc_next != quick_malloc_heap)
+        quick_malloc_next = quick_malloc_heap;
+}
+
+void port_syscall(struct port_extctx *ctxp, uint32_t n)
+{
+    switch (n) {
+    case 0:
+        *reinterpret_cast<void **>(ctxp->r0) = quick_malloc(ctxp->r1);
+        break;
+    case 1:
+        quick_freeall();
+        break;
+    }
+
+    chSysHalt("svc");
+}
+