Changeset dc41772 in mainline

Timestamp:

2018-11-18T01:00:49Z (5 years ago)

Author:

Jiri Svoboda <jiri@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

ec18e454

Parents:

e131833c

Message:

Revert "Remove dead code" - needs more work

This reverts commit 9a791eb9411b32c4c733f382971ad899794149b1.

File:

• kernel/arch/ia32/src/boot/multiboot.S (modified) (2 diffs)

kernel/arch/ia32/src/boot/multiboot.S

@@ -49 +49 @@
 
 .code32
+
+.macro pm_error msg
+        movl \msg, %esi
+        jmp pm_error_halt
+.endm
 
 .macro pm_status msg
@@ -365 +370 @@
 
                         ret
+
+/** Print string to EGA display (in light red) and halt.
+ *
+ * Should be executed from 32 bit protected mode with paging
+ * turned off. Stack is not required. This routine is used even
+ * if CONFIG_EGA is not enabled. Since we are going to halt the
+ * CPU anyway, it is always better to at least try to print
+ * some hints.
+ *
+ * @param %esi NULL-terminated string to print.
+ *
+ */
+pm_error_halt:
+        movl $0xb8000, %edi  /* base of EGA text mode memory */
+        xorl %eax, %eax
+
+        /* Read bits 8 - 15 of the cursor address */
+        movw $0x3d4, %dx
+        movb $0xe, %al
+        outb %al, %dx
+
+        movw $0x3d5, %dx
+        inb %dx, %al
+        shl $8, %ax
+
+        /* Read bits 0 - 7 of the cursor address */
+        movw $0x3d4, %dx
+        movb $0xf, %al
+        outb %al, %dx
+
+        movw $0x3d5, %dx
+        inb %dx, %al
+
+        /* Sanity check for the cursor on screen */
+        cmp $2000, %ax
+        jb err_cursor_ok
+
+                movw $1998, %ax
+
+        err_cursor_ok:
+
+        movw %ax, %bx
+        shl $1, %eax
+        addl %eax, %edi
+
+        err_ploop:
+                lodsb
+
+                cmp $0, %al
+                je err_ploop_end
+
+                movb $0x0c, %ah  /* black background, light red foreground */
+                stosw
+
+                /* Sanity check for the cursor on the last line */
+                inc %bx
+                cmp $2000, %bx
+                jb err_ploop
+
+                /* Scroll the screen (24 rows) */
+                movl %esi, %edx
+                movl $0xb80a0, %esi
+                movl $0xb8000, %edi
+                movl $960, %ecx
+                rep movsl
+
+                /* Clear the 24th row */
+                xorl %eax, %eax
+                movl $40, %ecx
+                rep stosl
+
+                /* Go to row 24 */
+                movl %edx, %esi
+                movl $0xb8f00, %edi
+                movw $1920, %bx
+
+                jmp err_ploop
+        err_ploop_end:
+
+        /* Write bits 8 - 15 of the cursor address */
+        movw $0x3d4, %dx
+        movb $0xe, %al
+        outb %al, %dx
+
+        movw $0x3d5, %dx
+        movb %bh, %al
+        outb %al, %dx
+
+        /* Write bits 0 - 7 of the cursor address */
+        movw $0x3d4, %dx
+        movb $0xf, %al
+        outb %al, %dx
+
+        movw $0x3d5, %dx
+        movb %bl, %al
+        outb %al, %dx
+
+        cli
+        hlt1:
+                hlt
+                jmp hlt1
 
 /** Print string to EGA display (in light green).