Add subprocesses and convert terminal to an app

meson.build

@@ -38,7 +38,15 @@ kernel_entry_o = custom_target(
   command: [nasm, '-f', 'elf64', '@INPUT@', '-o', '@OUTPUT@'],
 )
 
-syscall_o = custom_target('syscall',
+process_o = custom_target(
+  'process',
+  input:  'src/kernel/process.asm',
+  output: 'process.o',
+  command: [nasm, '-f', 'elf64', '@INPUT@', '-o', '@OUTPUT@'],
+)
+
+syscall_o = custom_target(
+  'syscall',
   input:  'src/kernel/syscall.asm',
   output: 'syscall.o',
   command: [nasm, '-f', 'elf64', '@INPUT@', '-o', '@OUTPUT@'],
@@ -46,10 +54,12 @@ syscall_o = custom_target('syscall',
 
 cc = meson.get_compiler('c')
 
-kernel_sources = files(
-  'src/kernel/app/cat.c',
-  'src/kernel/app/ls.c',
-  'src/kernel/app/terminal.c',
+lib_sources = files([
+  'src/lib/memory.c',
+  'src/lib/string.c',
+])
+
+kernel_sources = files([
   'src/kernel/ata.c',
   'src/kernel/fat16.c',
   'src/kernel/fs.c',
@@ -65,13 +75,11 @@ kernel_sources = files(
   'src/kernel/syscall.c',
   'src/kernel/tss.c',
   'src/kernel/vga.c',
-  'src/lib/memory.c',
-  'src/lib/string.c',
-)
+])
 
 kernel_elf = executable(
   'kernel.elf',
-  sources: [kernel_entry_o, syscall_o, kernel_sources],
+  sources: [kernel_entry_o, process_o, syscall_o, lib_sources, kernel_sources],
   c_args: [
     '-ffreestanding',
     '-nostdlib',
@@ -99,28 +107,29 @@ custom_target(
   build_by_default: true,
 )
 
-hello_start = custom_target(
-  'hello_start',
+terminal_start = custom_target(
+  'terminal_start',
   input:  'src/user/start.asm',
-  output: 'hello_start.o',
+  output: 'terminal_start.o',
   command: [nasm, '-f', 'elf64', '-o', '@OUTPUT@', '@INPUT@'],
 )
 
-hello_syscall = custom_target(
-  'hello_syscall',
+terminal_syscall = custom_target(
+  'terminal_syscall',
   input:  'src/user/syscall.asm',
-  output: 'hello_syscall.o',
+  output: 'terminal_syscall.o',
   command: [nasm, '-f', 'elf64', '-o', '@OUTPUT@', '@INPUT@'],
 )
 
-hello_elf = executable(
-  'hello.elf',
-  sources: [hello_start, hello_syscall, 'src/user/app/hello/hello.c'],
+terminal_elf = executable(
+  'terminal.elf',
+  sources: [terminal_start, terminal_syscall, lib_sources, 'src/user/app/terminal/terminal.c'],
   c_args: [
     '-ffreestanding',
     '-nostdlib',
     '-fno-stack-protector',
     '-mcmodel=large',
+    '-DVERSION="' + meson.project_version() + '"',
   ],
   link_args: [
     '-T', meson.project_source_root() / 'src/user/linker.ld',
@@ -130,9 +139,49 @@ hello_elf = executable(
 )
 
 custom_target(
-  'hello_bin',
-  input:  hello_elf,
-  output: 'hello.bin',
+  'terminal',
+  input:  terminal_elf,
+  output: 'terminal',
+  command: ['objcopy', '-O', 'binary', '@INPUT@', '@OUTPUT@'],
+  build_by_default: true,
+)
+
+
+echo_start = custom_target(
+  'echo_start',
+  input:  'src/user/start.asm',
+  output: 'echo_start.o',
+  command: [nasm, '-f', 'elf64', '-o', '@OUTPUT@', '@INPUT@'],
+)
+
+echo_syscall = custom_target(
+  'echo_syscall',
+  input:  'src/user/syscall.asm',
+  output: 'echo_syscall.o',
+  command: [nasm, '-f', 'elf64', '-o', '@OUTPUT@', '@INPUT@'],
+)
+
+echo_elf = executable(
+  'echo.elf',
+  sources: [echo_start, echo_syscall, lib_sources, 'src/user/app/echo/echo.c'],
+  c_args: [
+    '-ffreestanding',
+    '-nostdlib',
+    '-fno-stack-protector',
+    '-mcmodel=large',
+    '-DVERSION="' + meson.project_version() + '"',
+  ],
+  link_args: [
+    '-T', meson.project_source_root() / 'src/user/linker.ld',
+    '-nostdlib',
+  ],
+  link_depends: 'src/user/linker.ld',
+)
+
+custom_target(
+  'echo',
+  input:  echo_elf,
+  output: 'echo',
   command: ['objcopy', '-O', 'binary', '@INPUT@', '@OUTPUT@'],
   build_by_default: true,
 )