ibmpc: PC implementation of the fast page copy and clear

diff --git a/Kernel/platform-ibmpc/ibmpc.S b/Kernel/platform-ibmpc/ibmpc.S
index 56aa953..8c1c09a 100644 (file)
--- a/Kernel/platform-ibmpc/ibmpc.S
+++ b/Kernel/platform-ibmpc/ibmpc.S
@@ -31,6 +31,8 @@ istack_top:
        .global biosdata_read
        .global equipment_word
 
+       .global do_copy_page
+       .global do_zero_page
 
 init_early:
        /* Dig useful information out of the BIOS */
@@ -418,6 +420,47 @@ biosdata_read:
        popw    %bp
        ret
 
+do_copy_page:
+       pushw   %bp
+       movw    %sp,%bp
+       pushw   %es
+       pushw   %ds
+       pushw   %si
+       pushw   %di
+       movw    4(%bp),%ax
+       movw    %ax,%es
+       movw    6(%bp),%ax
+       movw    %ax,%ds
+       xorw    %si,%si
+       movw    %si,%di
+       movw    $0x0800,%cx     /* Change me if not using 4K pages */
+       rep     movsw
+       popw    %di
+       popw    %si
+       popw    %ds
+       popw    %es
+       popw    %bp
+       ret
+
+do_zero_page:
+       pushw   %bp
+       movw    %sp,%bp
+       pushw   %es
+       pushw   %di
+       movw    4(%bp),%ax
+       movw    %ax,%es
+       movw    6(%bp),%ax
+       movw    %ax,%ds
+       xorw    %ax,%ax
+       xorw    %ax,%si
+       movw    %ax,%di
+       movw    $0x0800,%cx     /* Change me if not using 4K pages */
+       rep     stosw
+       popw    %si
+       popw    %es
+       popw    %bp
+       ret
+       
 kernel_ds:
        .word 0