done for tonight. need to read elf bytewise

yeah, I guess it was just a coincidence that the segment was aligned.

turns out that I need to do what I thought in the first place.

fsdir/Programs/src/shell.c

@@ -9,9 +9,7 @@ int main(int argc, char** argv)
 
 	int i;
 	for (i = 0; i < argc; i++) {
-		sys_write(1, "Arg: ", 4);
-		sys_write(1, argv[i], strlen(argv[i]));
-		sys_write(1, "\n", 1);
+		printf("Arg%d: %s\n", i, argv[i]);
 	}
 
 	uint8_t test[64];

kernel/Filesystem/ext2.c

@@ -35,6 +35,34 @@ uint32_t ext2_get_inode(uint32_t inode_num, inode_t* buf)
 	return 0;
 }
 
+uint32_t ext2_read_sectors(uint32_t inode_num, uint32_t start, uint32_t count, uint16_t* buf)
+{
+	if (!buf)
+		return -1;
+
+	inode_t inode;
+	ext2_get_inode(inode_num, &inode);
+
+	uint32_t sectors_read = 0;
+
+	// step 1: determine which block.
+	uint32_t block = start / 2;
+
+	// step 2: which sector in that block do we want?
+	uint32_t sector = start % 2;
+	printf("start %d block %d sector %d\n", start, block, sector);
+
+	// read the first (maybe misaligned) sector(s)
+	int i;
+	for (i = sector; i < 2 && sectors_read < count; i++) {
+		if (!inode.block_pointer[block])
+			break;
+		printf("Reading from inode %x block %x sector %x into %#x\n", inode_num, block, i, buf + sectors_read * 256);
+		ata_read_sectors(ATA_MASTER, ext2_base + inode.block_pointer[block] * 2 + i, 1, buf + sectors_read * 256);
+		sectors_read++;
+	}
+}
+
 uint32_t ext2_read_data(uint32_t inode_num, uint32_t count, uint16_t* buf)
 {
 	if (!buf)

kernel/Filesystem/ext2.h

@@ -122,6 +122,7 @@ typedef struct dir_entry {
 
 uint32_t ext2_init(uint32_t base);
 uint32_t ext2_get_inode(uint32_t inode_num, inode_t* buf);
+uint32_t ext2_read_sectors(uint32_t inode_num, uint32_t start, uint32_t count, uint16_t* buf);
 uint32_t ext2_read_data(uint32_t inode_num, uint32_t count, uint16_t* buf);
 uint32_t ext2_find_inode_num(const int8_t* filename);
 uint32_t ext2_find_inode(const int8_t* filename, inode_t* inode);

kernel/Syscalls/execute.c

@@ -10,6 +10,8 @@
 
 #define PCB_MASK	0xffffe000
 
+#define divhi(x, y) (x/y + (x % y != 0))
+
 // TEMPORARY!!!
 static uint32_t pid = 0;
 
@@ -162,10 +164,34 @@ int32_t _sys_exec(uint8_t* cmd)
 		printf("arg%d: %s\n", i, argv[i]);
 	}
 
-	elf_header_t* header = (elf_header_t*)data.data8;
+	elf_header_t* e_header = (elf_header_t*)data.data8;
+
+	printf("Program header count: %d\n", e_header->e_phnum);
+	printf("Program header size: %x\n", e_header->e_phentsize);
+	printf("Program header offset: %x\n", e_header->e_phoff);
+
+	program_header_t* p_header[e_header->e_phnum]; 
+	
+	for (i = 0; i < e_header->e_phnum; i++) {
+		p_header[i] = (program_header_t*)(data.data8 + e_header->e_phoff + i * e_header->e_phentsize);
+	}
+
 
 	map_large(EXEC_BASE_ADDR, _8MB + pid * _4MB);
 	ext2_read_data(parsed_inode, 0, (uint16_t*)EXEC_LOAD_ADDR);
+
+	// what if you...
+	// read the program header to see how many bytes you needed to allocate and where
+	// wrote an ext2 read where you could specifiy a starting point in the inode and bytes to read
+
+	for (i = 0; i < e_header->e_phnum; i++) {
+		printf("Program header %d type %x flags %x", i, p_header[i]->p_type, p_header[i]->p_flags);
+		printf(" offset %x vaddr %#x paddr %#x size %x\n", 
+			p_header[i]->p_offset, p_header[i]->p_vaddr, p_header[i]->p_paddr, p_header[i]->p_filesz);
+		// so there are the two program segments that we need to load.
+	}
+
+	ext2_read_sectors(parsed_inode, p_header[1]->p_offset/512, divhi(p_header[1]->p_memsz, 512), p_header[1]->p_vaddr);
 	
 
 	*USER_ARGC = argc;
@@ -190,7 +216,7 @@ int32_t _sys_exec(uint8_t* cmd)
 	iret                 \n\
 	pop %2"
 	: "=m"(pcb->parent_ebp), "=m"(pcb->parent_esp), "=m"(status)
-	: "r"(header->e_entry)
+	: "r"(e_header->e_entry)
 	: "%eax"
 	);
 

kernel/Syscalls/execute.h

@@ -71,6 +71,36 @@ typedef struct elf_header{
         uint16_t e_shstrndx;
 } elf_header_t;
 
+#define PT_NULL 0
+#define PT_LOAD 1
+#define PT_DYNAMIC 2
+#define PT_INTERP 3
+#define PT_NOTE 4
+#define PT_SHLIB 5
+#define PT_PHDR 6
+#define PT_TLS 7
+#define PT_LOOS 0x60000000
+#define PT_HIOS 0x6fffffff
+#define PT_LOPROC 0x70000000
+#define PT_HIPROC 0x7fffffff
+
+#define PF_X 1
+#define PF_W 2
+#define PF_R 4
+#define PF_MASKOS 0x0ff00000
+#define PF_MASKPROC 0xf0000000
+
+typedef struct program_header {
+	uint32_t p_type;
+	uint32_t p_offset;
+	uint32_t p_vaddr;
+	uint32_t p_paddr;
+	uint32_t p_filesz;
+	uint32_t p_memsz;
+	uint32_t p_flags;
+	uint32_t p_align;
+} program_header_t;
+
 #define MAX_FD 8
 
 typedef struct pcb {