Ticket #5163: boot_keys3.patch

src/system/boot/platform/bios_ia32/bios.S

@@ -22 +22 @@
 #define SAVED_EAX       0x10008
 #define SAVED_ES        0x1000c
 #define SAVED_FLAGS     0x10010
+#define SAVED_EBP       0x10014
     // we're overwriting the start of our boot loader to hold some
     // temporary values - the first 1024 bytes of it are used at
     // startup only, and we avoid some linking issues this way
@@ -74 +75 @@
     // setup protected stack frame again
     movl    SAVED_ESP, %eax
     movl    %eax, %esp
-    movl    %eax, %ebp
+    movl    SAVED_EBP, %ebp
 
     // copy the return address to the current stack
     movl    REAL_MODE_STACK, %eax
@@ -96 +97 @@
     movl    %esp, %eax
     movl    %eax, SAVED_ESP
 
+    movl    %ebp, SAVED_EBP
+
     // put the return address on the real mode stack
     movl    (%esp), %eax
     movl    %eax, REAL_MODE_STACK
@@ -232 +235 @@
 
 //--------------------------------------------------------------
 
+/** uint32  search_keyboard_buffer()
+ *  Search in keyboard buffer keycodes for F8, F12 or Space 
+ *  if not found - search ESC keycode.
+ */
+
+FUNCTION(search_keyboard_buffer)
+    pushal
+    pushfl
+
+    // make sure the correct IDT is in place
+    lidt    idt_descriptor
+
+    call    switch_to_real_mode
+    .code16
+
+    cld
+    push    %ds
+    xorl    %eax, %eax
+    mov %ax, %ds
+    mov $0x41E, %si // BIOS kbd buffer
+search_cycle1:
+    lodsw
+    cmp $0x4200, %ax    // test F8 key
+    jz  to_ret
+    cmp $0x8600, %ax    // test F12 key
+    jz  to_ret
+    cmp $0x3920, %ax    // test Space key
+    jz  to_ret
+    cmp $0x440, %si
+    jnz search_cycle1
+
+    movw    $0x41E, %si // BIOS kbd buffer
+search_cycle2:
+    lodsw
+    cmp $0x011B, %ax    // test ESC key
+    jz  to_ret
+    cmp $0x440, %si
+    jnz search_cycle2
+to_ret:
+    pop %ds
+
+    // save %eax
+    movl    %eax, (SAVED_EAX - 0x10000)
+
+    call    switch_to_protected_mode
+    .code32
+
+    popfl
+    popal
+
+    // restore %eax
+    movl    SAVED_EAX, %eax
+
+    ret
+
+//--------------------------------------------------------------
+
 .globl idt_descriptor
 idt_descriptor:
     .short  0x7ff               // IDT at 0x0, default real mode location

src/system/boot/platform/bios_ia32/keyboard.cpp

@@ -58 +58 @@
 extern "C" uint32
 check_for_boot_keys(void)
 {
-    union key key;
+    bios_regs regs;
     uint32 options = 0;
-
-    while ((key.ax = check_for_key()) != 0) {
-        switch (key.code.ascii) {
-            case ' ':
-                options |= BOOT_OPTION_MENU;
-                break;
-            case 0x1b:  // escape
-                options |= BOOT_OPTION_DEBUG_OUTPUT;
-                break;
-            case 0:
-                // evaluate BIOS scan codes
-                // ...
-                break;
-        }
+    uint32 keycode = 0;
+    regs.eax = 0x0200;
+    call_bios(0x16, &regs);
+        // Read Keyboard flags. bit 0 LShift, bit 1 RShift
+    if ((regs.eax & 0x03) != 0) {
+        // LShift or RShift - option menu
+        options |= BOOT_OPTION_MENU;
+    } else {
+        keycode = search_keyboard_buffer();
+        if (keycode == 0x4200 || keycode == 0x8600 || keycode == 0x3920) {
+            // F8 or F12 or Space - option menu
+            options |= BOOT_OPTION_MENU;
+        } else if (keycode == 0x011B) {
+            // ESC - debug output
+            options |= BOOT_OPTION_DEBUG_OUTPUT;
+        }
     }
 
     dprintf("options = %ld\n", options);

src/system/boot/platform/bios_ia32/bios.h

@@ -41 +41 @@
 "C"
 #endif
 void call_bios(uint8 num, struct bios_regs *regs);
+extern
+#ifdef __cplusplus
+"C"
+#endif
+uint32 search_keyboard_buffer();
 
 #endif  /* BIOS_H */

src/system/boot/platform/bios_ia32/start.c

@@ -129 +129 @@
     mmu_init();
     parse_multiboot_commandline(&args);
 
-    // wait a bit to give the user the opportunity to press a key
-    spin(750000);
-
     // reading the keyboard doesn't seem to work in graphics mode
     // (maybe a bochs problem)
     sBootOptions = check_for_boot_keys();