Improved mac support

src/os/linux/elf/elf.md

@@ -0,0 +1,30 @@
+# ELF
+
+## Basic structure
+
+1. ELF header (0x00 - 0x40)
+2. Program header (0x40 - 0x78)
+3. Padding (0x78 - 0x80)
+4. Machine code (0x80)
+
+## Entry point
+
+The entry point is defined in the first 64 bytes (ELF header).
+
+## Base address
+
+The minimum base address is controlled by the `mmap` settings:
+
+```shell
+sysctl vm.mmap_min_addr
+```
+
+Usually, this value is 65536 (0x1000).
+
+## Initialization in Linux
+
+ELF loader:
+https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/fs/binfmt_elf.c
+
+ELF register definitions:
+https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/x86/include/asm/elf.h