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authordzwdz2022-03-27 17:49:54 +0200
committerdzwdz2022-03-27 17:49:54 +0200
commitf1cefa851c3bc8aa6a8c2e6b86d23d87db342a2d (patch)
treeba5a67cbf7a60f19bbe6a2ca83dedf2132b991ba
parent2cd4a60b2f8dd3fc5196fe97c6f1882e2e8ebe0d (diff)
init: userland tty emulator ; also workaround a fork() bug
-rw-r--r--src/init/ansiterm.c95
-rw-r--r--src/init/main.c10
-rw-r--r--src/kernel/syscalls.c8
3 files changed, 106 insertions, 7 deletions
diff --git a/src/init/ansiterm.c b/src/init/ansiterm.c
new file mode 100644
index 0000000..c66d39b
--- /dev/null
+++ b/src/init/ansiterm.c
@@ -0,0 +1,95 @@
+#include <shared/syscalls.h>
+
+struct vga_cell {
+ unsigned char c;
+ unsigned char style;
+} __attribute__((__packed__));
+static struct vga_cell vga[80 * 25];
+
+static handle_t tty_fd;
+static handle_t vga_fd;
+
+static struct {int x, y;} cursor = {0};
+
+
+static void flush(void) {
+ _syscall_write(vga_fd, vga, sizeof vga, 0);
+}
+
+static void scroll(void) {
+ for (size_t i = 0; i < 80 * 24; i++)
+ vga[i] = vga[i + 80];
+ for (size_t i = 80 * 24; i < 80 * 25; i++)
+ vga[i].c = ' ';
+ cursor.y--;
+}
+
+static void in_char(char c) {
+ switch (c) {
+ case '\n':
+ cursor.x = 0;
+ cursor.y++;
+ break;
+ case '\b':
+ if (--cursor.x < 0) cursor.x = 0;
+ break;
+ default:
+ vga[cursor.y * 80 + cursor.x++].c = c;
+ }
+
+ if (cursor.x >= 80) {
+ cursor.x = 0;
+ cursor.y++;
+ }
+ while (cursor.y >= 25) scroll();
+}
+
+void ansiterm_drv(void) {
+ tty_fd = _syscall_open("/tty", 4);
+ _syscall_write(tty_fd, "ansiterm...\n", 12, 0);
+
+ vga_fd = _syscall_open("/vga", 4);
+ _syscall_read(vga_fd, vga, sizeof vga, 0);
+
+ // find first empty line
+ for (cursor.y = 0; cursor.y < 25; cursor.y++) {
+ for (cursor.x = 0; cursor.x < 80; cursor.x++) {
+ char c = vga[cursor.y * 80 + cursor.x].c;
+ if (c != ' ' && c != '\0') break;
+ }
+ if (cursor.x == 80) break;
+ }
+ cursor.x = 0;
+
+ static char buf[512];
+ struct fs_wait_response res;
+ while (!_syscall_fs_wait(buf, sizeof buf, &res)) {
+ switch (res.op) {
+ case VFSOP_OPEN:
+ // TODO check path
+ _syscall_fs_respond(NULL, 1);
+ break;
+
+ case VFSOP_WRITE:
+ _syscall_write(tty_fd, buf, res.len, 0);
+ for (int i = 0; i < res.len; i++)
+ in_char(buf[i]);
+ flush();
+ _syscall_fs_respond(NULL, res.len);
+ break;
+
+ case VFSOP_READ:
+ if (res.capacity > sizeof buf)
+ res.capacity = sizeof buf;
+ size_t len = _syscall_read(tty_fd, buf, res.capacity, 0);
+ _syscall_fs_respond(buf, len);
+ break;
+
+ default:
+ _syscall_fs_respond(NULL, -1);
+ break;
+ }
+ }
+
+ _syscall_exit(1);
+}
diff --git a/src/init/main.c b/src/init/main.c
index ba5fdcd..1b9c7ed 100644
--- a/src/init/main.c
+++ b/src/init/main.c
@@ -17,21 +17,19 @@ extern char _initrd;
void read_file(const char *path, size_t len);
void fs_prep(void);
+void ansiterm_drv(void); // TODO header file
+
__attribute__((section(".text.startup")))
int main(void) {
// allocate bss
_syscall_memflag(&_bss_start, &_bss_end - &_bss_start, MEMFLAG_PRESENT);
+ if (!fork2_n_mount("/tty")) ansiterm_drv();
+
__tty_fd = _syscall_open("/tty", sizeof("/tty") - 1);
if (__tty_fd < 0)
_syscall_exit(1);
- // change screen color
- handle_t vga = _syscall_open(argify("/vga"));
- for (int i = 1; i < 80*25*2; i += 2)
- _syscall_write(vga, "\x4f", 1, i);
- _syscall_close(vga);
-
fs_prep();
shell_loop();
diff --git a/src/kernel/syscalls.c b/src/kernel/syscalls.c
index f41aabf..faa7ccc 100644
--- a/src/kernel/syscalls.c
+++ b/src/kernel/syscalls.c
@@ -179,7 +179,13 @@ handle_t _syscall_fs_fork2(void) {
* also there's this whole thing with handling errors here properly and
* errno
* TODO figure this out */
- if (front == 0) panic_unimplemented();
+ if (front == 0) {
+ // dumb hack
+ front = process_find_handle(process_current);
+ if (front < 0) return -1;
+ process_current->handles[front].type = HANDLE_FS_FRONT;
+ process_current->handles[0].type = HANDLE_EMPTY;
+ }
backend = kmalloc(sizeof *backend); // TODO never freed
backend->type = VFS_BACK_USER;