feat(user): add user-space build system and init process to test fork/wait

1 files changed, 215 insertions, 0 deletions

diff --git a/build/user/initcode.asm b/build/user/initcode.asm
new file mode 100644
index 0000000..e3a1185
--- /dev/null
+++ b/build/user/initcode.asm
@@ -0,0 +1,215 @@
+
+build/user/initcode.out:     file format elf64-littleriscv
+
+
+Disassembly of section .text:
+
+0000000000000000 <_start>:
+#include "user/user.h"
+
+int main();
+
+extern "C" void _start()
+{
+   0:	1141                	addi	sp,sp,-16
+   2:	e406                	sd	ra,8(sp)
+    exit(main());
+   4:	004000ef          	jal	8 <main>
+
+0000000000000008 <main>:
+}
+
+int main()
+{
+   8:	1141                	addi	sp,sp,-16
+   a:	e406                	sd	ra,8(sp)
+    int pid = fork();
+   c:	060000ef          	jal	6c <fork>
+
+    if (pid < 0)
+  10:	00054f63          	bltz	a0,2e <main+0x26>
+    {
+        write(1, "Fork failed\n", 12);
+        exit(1);
+    }
+
+    if (pid == 0)
+  14:	e905                	bnez	a0,44 <main+0x3c>
+    {
+        write(1, "Hello from Child!\n", 18);
+  16:	4649                	li	a2,18
+  18:	00000597          	auipc	a1,0x0
+  1c:	12058593          	addi	a1,a1,288 # 138 <putc+0x24>
+  20:	4505                	li	a0,1
+  22:	072000ef          	jal	94 <write>
+        exit(0);
+  26:	4501                	li	a0,0
+  28:	04c000ef          	jal	74 <exit>
+        write(1, "Parent waiting...\n", 18);
+        wait(0);
+        write(1, "Parent: Child exited.\n", 22);
+    }
+
+    while (1);
+  2c:	a001                	j	2c <main+0x24>
+        write(1, "Fork failed\n", 12);
+  2e:	4631                	li	a2,12
+  30:	00000597          	auipc	a1,0x0
+  34:	0f058593          	addi	a1,a1,240 # 120 <putc+0xc>
+  38:	4505                	li	a0,1
+  3a:	05a000ef          	jal	94 <write>
+        exit(1);
+  3e:	4505                	li	a0,1
+  40:	034000ef          	jal	74 <exit>
+        write(1, "Parent waiting...\n", 18);
+  44:	4649                	li	a2,18
+  46:	00000597          	auipc	a1,0x0
+  4a:	10a58593          	addi	a1,a1,266 # 150 <putc+0x3c>
+  4e:	4505                	li	a0,1
+  50:	044000ef          	jal	94 <write>
+        wait(0);
+  54:	4501                	li	a0,0
+  56:	026000ef          	jal	7c <wait>
+        write(1, "Parent: Child exited.\n", 22);
+  5a:	4659                	li	a2,22
+  5c:	00000597          	auipc	a1,0x0
+  60:	10c58593          	addi	a1,a1,268 # 168 <putc+0x54>
+  64:	4505                	li	a0,1
+  66:	02e000ef          	jal	94 <write>
+  6a:	b7c9                	j	2c <main+0x24>
+
+000000000000006c <fork>:
+    name: \
+        li a7, SYS_ ## name; \
+        ecall; \
+        ret
+
+SYSCALL(fork)
+  6c:	4889                	li	a7,2
+  6e:	00000073          	ecall
+  72:	8082                	ret
+
+0000000000000074 <exit>:
+SYSCALL(exit)
+  74:	488d                	li	a7,3
+  76:	00000073          	ecall
+  7a:	8082                	ret
+
+000000000000007c <wait>:
+SYSCALL(wait)
+  7c:	4891                	li	a7,4
+  7e:	00000073          	ecall
+  82:	8082                	ret
+
+0000000000000084 <pipe>:
+SYSCALL(pipe)
+  84:	4895                	li	a7,5
+  86:	00000073          	ecall
+  8a:	8082                	ret
+
+000000000000008c <read>:
+SYSCALL(read)
+  8c:	4899                	li	a7,6
+  8e:	00000073          	ecall
+  92:	8082                	ret
+
+0000000000000094 <write>:
+SYSCALL(write)
+  94:	48c5                	li	a7,17
+  96:	00000073          	ecall
+  9a:	8082                	ret
+
+000000000000009c <close>:
+SYSCALL(close)
+  9c:	48d9                	li	a7,22
+  9e:	00000073          	ecall
+  a2:	8082                	ret
+
+00000000000000a4 <kill>:
+SYSCALL(kill)
+  a4:	489d                	li	a7,7
+  a6:	00000073          	ecall
+  aa:	8082                	ret
+
+00000000000000ac <exec>:
+SYSCALL(exec)
+  ac:	48a1                	li	a7,8
+  ae:	00000073          	ecall
+  b2:	8082                	ret
+
+00000000000000b4 <open>:
+SYSCALL(open)
+  b4:	48c1                	li	a7,16
+  b6:	00000073          	ecall
+  ba:	8082                	ret
+
+00000000000000bc <mknod>:
+SYSCALL(mknod)
+  bc:	48c9                	li	a7,18
+  be:	00000073          	ecall
+  c2:	8082                	ret
+
+00000000000000c4 <unlink>:
+SYSCALL(unlink)
+  c4:	48cd                	li	a7,19
+  c6:	00000073          	ecall
+  ca:	8082                	ret
+
+00000000000000cc <fstat>:
+SYSCALL(fstat)
+  cc:	48a5                	li	a7,9
+  ce:	00000073          	ecall
+  d2:	8082                	ret
+
+00000000000000d4 <link>:
+SYSCALL(link)
+  d4:	48d1                	li	a7,20
+  d6:	00000073          	ecall
+  da:	8082                	ret
+
+00000000000000dc <mkdir>:
+SYSCALL(mkdir)
+  dc:	48d5                	li	a7,21
+  de:	00000073          	ecall
+  e2:	8082                	ret
+
+00000000000000e4 <chdir>:
+SYSCALL(chdir)
+  e4:	48a9                	li	a7,10
+  e6:	00000073          	ecall
+  ea:	8082                	ret
+
+00000000000000ec <dup>:
+SYSCALL(dup)
+  ec:	48ad                	li	a7,11
+  ee:	00000073          	ecall
+  f2:	8082                	ret
+
+00000000000000f4 <getpid>:
+SYSCALL(getpid)
+  f4:	48b1                	li	a7,12
+  f6:	00000073          	ecall
+  fa:	8082                	ret
+
+00000000000000fc <sbrk>:
+SYSCALL(sbrk)
+  fc:	48b5                	li	a7,13
+  fe:	00000073          	ecall
+ 102:	8082                	ret
+
+0000000000000104 <sleep>:
+SYSCALL(sleep)
+ 104:	48b9                	li	a7,14
+ 106:	00000073          	ecall
+ 10a:	8082                	ret
+
+000000000000010c <uptime>:
+SYSCALL(uptime)
+ 10c:	48bd                	li	a7,15
+ 10e:	00000073          	ecall
+ 112:	8082                	ret
+
+0000000000000114 <putc>:
+ 114:	4885                	li	a7,1
+ 116:	00000073          	ecall
+ 11a:	8082                	ret