bios: Move terminal entirely to stage 3

stage23/drivers/vga_textmode.c

@@ -15,7 +15,7 @@
 #define VD_COLS (80 * 2)
 #define VD_ROWS 25
 
-static uint8_t *video_mem = (uint8_t *)0xb8000;
+static volatile uint8_t *video_mem = (uint8_t *)0xb8000;
 
 static uint8_t *back_buffer = NULL;
 static uint8_t *front_buffer = NULL;

stage23/entry.s2.c

@@ -49,7 +49,6 @@ static bool stage3_init(struct volume *part) {
     stage3_found = true;
 
     if (stage3->size != (size_t)limine_sys_size) {
-        term_textmode();
         print("limine.sys size incorrect.\n");
         return false;
     }
@@ -61,7 +60,6 @@ static bool stage3_init(struct volume *part) {
     fclose(stage3);
 
     if (memcmp(build_id_s2 + 16, build_id_s3 + 16, 20) != 0) {
-        term_textmode();
         print("limine.sys build ID mismatch.\n");
         return false;
     }
@@ -82,8 +80,6 @@ noreturn void entry(uint8_t boot_drive, int boot_from) {
     if (!a20_enable())
         panic(false, "Could not enable A20 line");
 
-    term_notready();
-
     struct rm_regs r = {0};
     r.eax = 0x0003;
     rm_int(0x10, &r, &r);
@@ -112,7 +108,6 @@ noreturn void entry(uint8_t boot_drive, int boot_from) {
     );
 
     if (!stage3_found) {
-        term_textmode();
         print("\n"
               "!! Stage 3 file not found!\n"
               "!! Have you copied limine.sys to the root or /boot directories of\n"

stage23/entry.s3.c

@@ -127,6 +127,8 @@ noreturn void uefi_entry(EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE *SystemTable)
 #endif
 
 noreturn void stage3_common(void) {
+    term_notready();
+
     init_flush_irqs();
     init_io_apics();
 

stage23/lib/panic.s2.c

@@ -21,7 +21,11 @@ noreturn void panic(bool allow_menu, const char *fmt, ...) {
 
     quiet = false;
 
-    if (term_backend == NOT_READY) {
+    if (
+#if bios == 1
+      stage3_loaded == true &&
+#endif
+      term_backend == NOT_READY) {
 #if bios == 1
         term_textmode();
 #elif uefi == 1
@@ -29,11 +33,19 @@ noreturn void panic(bool allow_menu, const char *fmt, ...) {
 #endif
     }
 
-    if (term_backend == NOT_READY) {
+    if (
+#if bios == 1
+      stage3_loaded == true &&
+#endif
+      term_backend == NOT_READY) {
         term_fallback();
     }
 
-    print("\033[31mPANIC\033[37;1m\033[0m: ");
+    if (stage3_loaded) {
+        print("\033[31mPANIC\033[37;1m\033[0m: ");
+    } else {
+        print("PANIC: ");
+    }
     vprint(fmt, args);
 
     va_end(args);

stage23/lib/print.s2.c

@@ -5,8 +5,34 @@
 #include <lib/blib.h>
 #include <lib/term.h>
 #include <lib/libc.h>
+#if bios == 1
+#include <lib/real.h>
+#endif
 #include <sys/cpu.h>
 
+#if bios == 1
+static void s2_print(const char *s, size_t len) {
+    for (size_t i = 0; i < len; i++) {
+        struct rm_regs r = {0};
+        char c = s[i];
+
+        switch (c) {
+            case '\n':
+                r.eax = 0x0e00 | '\r';
+                rm_int(0x10, &r, &r);
+                r = (struct rm_regs){0};
+                r.eax = 0x0e00 | '\n';
+                rm_int(0x10, &r, &r);
+                break;
+            default:
+                r.eax = 0x0e00 | s[i];
+                rm_int(0x10, &r, &r);
+                break;
+        }
+    }
+}
+#endif
+
 static const char *base_digits = "0123456789abcdef";
 
 #define PRINT_BUF_MAX 4096
@@ -187,7 +213,15 @@ void vprint(const char *fmt, va_list args) {
     }
 
 out:
-    term_write((uint64_t)(uintptr_t)print_buf, print_buf_i);
+#if bios == 1
+    if (stage3_loaded) {
+#endif
+        term_write((uint64_t)(uintptr_t)print_buf, print_buf_i);
+#if bios == 1
+    } else {
+        s2_print(print_buf, print_buf_i);
+    }
+#endif
 
     for (size_t i = 0; i < print_buf_i; i++) {
         if (E9_OUTPUT) {

stage23/linker_stage2only.ld

@@ -36,6 +36,9 @@ SECTIONS
         getchar_internal = .;
         getchar = .;
         menu = .;
+        term_write = .;
+        term_textmode = .;
+        term_fallback = .;
         stage3_addr = .;
         data_begin = .;
     }