making elf loader zero bss sections

makefile

@@ -8,7 +8,7 @@ out/disk.vdi: out/disk.img
 	VBoxManage convertfromraw out/disk.img out/disk.vdi --uuid a61929ed-3bf2-45ff-b98a-44f87c616dba
 
 out/disk.img: out/kernel.bin out/boot.bin out/fs
-  #TODO: have this regenerate after out/fs
+	#TODO: have this regenerate after out/fs
 	mkdir -p obj
 	/sbin/mkfs.fat -C -f 1 -F 16 -n "PORTLAND OS" -R 65 -s 1 -S 512 obj/shadow.img 8192
 	echo -n -e '\xeb\x3c' > obj/jmp.bin

src/kernel/elf.c

@@ -104,6 +104,8 @@ bool try_elf_run(const struct drive *d, const char *path, const char *pass_old_v
       continue;
     void *pma = pd_user_allocate(pd, entry->vma, (entry->vms - 1) / 4096 + 1, entry->flags & PH_WRITABLE);
     fmcpy(pma, d, h, entry->fa, entry->fs);
+    for (uint8_t *pma_i = pma + entry->fs; pma_i < pma + entry->vms; ++pma_i)
+      *pma_i = 0;
   }
 
   free_pages(phtable, phtable_pages);

src/user/include/knob/format.h

@@ -5,8 +5,8 @@
 #include <stdint.h>
 
 bool try_sntoi(const char *s, uint32_t n, uint32_t *out);
-void itosz(uint32_t i, char *out);
+void itosz(uint32_t i, char *out) __attribute__ ((access (write_only, 2)));
-void itosz_h8(uint8_t i, char *out);
+void itosz_h8(uint8_t i, char *out) __attribute__ ((access (write_only, 2)));
-void itosz_h32(uint32_t i, char *out);
+void itosz_h32(uint32_t i, char *out) __attribute__ ((access (write_only, 2)));
 
 #endif

src/user/knob/format.c

@@ -12,6 +12,7 @@ bool try_sntoi(const char *s, uint32_t n, uint32_t *out) {
   return true;
 }
 
+__attribute__ ((access (write_only, 2)))
 void itosz(uint32_t i, char *out) {
   if (!i) {
     *(uint16_t *)out = (uint16_t)'0';
@@ -32,12 +33,14 @@ void itosz(uint32_t i, char *out) {
 
 const char *const hex_digits = "0123456789abcdef";
 
+__attribute__ ((access (write_only, 2)))
 void itosz_h8(uint8_t i, char *out) {
   out[0] = hex_digits[i >> 4];
   out[1] = hex_digits[i & 0xf];
   out[2] = '\0';
 }
 
+__attribute__ ((access (write_only, 2)))
 void itosz_h32(uint32_t i, char *out) {
   for (uint8_t digit = 0; digit < 8; ++digit)
     out[digit] = hex_digits[(i >> (28 - digit * 4)) & 0xf];

src/user/knob/heap.c

@@ -24,9 +24,23 @@ static void add_header(struct block_header *bh) {
 
 __attribute__ ((malloc))
 void *get_block(uint32_t bytes) {
+//char nbuf[11];
+//tell_user_sz("[heap::get_block]\n  first_block = 0x");
+//itosz_h32((uint32_t)first_block, nbuf);
+//tell_user_sz(nbuf);
+//tell_user_sz("\n");
   struct block_header *header = 0;
 
   for (struct block_header *ptr = first_block; ptr; ptr = ptr->next) {
+  //tell_user_sz("  ptr = 0x");
+  //itosz_h32((uint32_t)ptr, nbuf);
+  //tell_user_sz(nbuf);
+  //tell_user_sz("\n  &ptr->allocated = 0x");
+  //itosz_h32((uint32_t)&ptr->allocated, nbuf);
+  //tell_user_sz(nbuf);
+  //tell_user_sz("\n  ptr->allocated = ");
+  //tell_user_sz(ptr->allocated ? "true\n" : "false\n");
+
     if (ptr->allocated)
       continue;
     if (ptr->length == bytes) {
@@ -49,7 +63,14 @@ void *get_block(uint32_t bytes) {
   if (!header) {
     uint32_t size_with_header = bytes + sizeof(struct block_header);
     if (!(size_with_header % 4096)) {
+    //tell_user_sz("  allocate ");
+    //itosz(size_with_header / 4096, nbuf);
+    //tell_user_sz(nbuf);
+    //tell_user_sz(" pages = 0x");
       header = _allocate_ram(size_with_header / 4096);
+    //itosz_h32((uint32_t)header, nbuf);
+    //tell_user_sz(nbuf);
+    //tell_user_sz("\n");
       if (!header)
         return 0;
       header->length = bytes;
@@ -57,7 +78,14 @@ void *get_block(uint32_t bytes) {
     }
     else {
       uint32_t pages = (bytes + sizeof(struct block_header) * 2) / 4096 + 1;
+    //tell_user_sz("  allocate ");
+    //itosz(pages, nbuf);
+    //tell_user_sz(nbuf);
+    //tell_user_sz(" pages = 0x");
       header = _allocate_ram(pages);
+    //itosz_h32((uint32_t)header, nbuf);
+    //tell_user_sz(nbuf);
+    //tell_user_sz("\n");
       if (!header)
         return 0;
       header->length = bytes;