[bios] Do not enable interrupts when printing to the console

There seems to be no reason for the sti/cli pair used around each call
to INT 10.  Remove these instructions, so that printing debug messages
from within an ISR does not temporarily reenable interrupts.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

diff --git a/src/arch/x86/interface/pcbios/bios_console.c b/src/arch/x86/interface/pcbios/bios_console.c
index c081a41e6fb440324cb8887ff758ce06106aa6d7..81e3a7d7e21aa6ae127b1c8db1761df252f52bb3 100644 (file)
--- a/src/arch/x86/interface/pcbios/bios_console.c
+++ b/src/arch/x86/interface/pcbios/bios_console.c
@@ -98,9 +98,7 @@ static void bios_handle_cup ( struct ansiesc_context *ctx __unused,
        if ( cy < 0 )
                cy = 0;
 
-       __asm__ __volatile__ ( REAL_CODE ( "sti\n\t"
-                                          "int $0x10\n\t"
-                                          "cli\n\t" )
+       __asm__ __volatile__ ( REAL_CODE ( "int $0x10\n\t" )
                               : : "a" ( 0x0200 ), "b" ( 1 ),
                                   "d" ( ( cy << 8 ) | cx ) );
 }
@@ -118,9 +116,7 @@ static void bios_handle_ed ( struct ansiesc_context *ctx __unused,
        /* We assume that we always clear the whole screen */
        assert ( params[0] == ANSIESC_ED_ALL );
 
-       __asm__ __volatile__ ( REAL_CODE ( "sti\n\t"
-                                          "int $0x10\n\t"
-                                          "cli\n\t" )
+       __asm__ __volatile__ ( REAL_CODE ( "int $0x10\n\t" )
                               : : "a" ( 0x0600 ), "b" ( bios_attr << 8 ),
                                   "c" ( 0 ),
                                   "d" ( ( ( console_height - 1 ) << 8 ) |
@@ -188,9 +184,7 @@ static void bios_handle_dectcem_set ( struct ansiesc_context *ctx __unused,
        /* Get character height */
        get_real ( height, BDA_SEG, BDA_CHAR_HEIGHT );
 
-       __asm__ __volatile__ ( REAL_CODE ( "sti\n\t"
-                                          "int $0x10\n\t"
-                                          "cli\n\t" )
+       __asm__ __volatile__ ( REAL_CODE ( "int $0x10\n\t" )
                               : : "a" ( 0x0100 ),
                                   "c" ( ( ( height - 2 ) << 8 ) |
                                         ( height - 1 ) ) );
@@ -207,9 +201,7 @@ static void bios_handle_dectcem_reset ( struct ansiesc_context *ctx __unused,
                                        unsigned int count __unused,
                                        int params[] __unused ) {
 
-       __asm__ __volatile__ ( REAL_CODE ( "sti\n\t"
-                                          "int $0x10\n\t"
-                                          "cli\n\t" )
+       __asm__ __volatile__ ( REAL_CODE ( "int $0x10\n\t" )
                               : : "a" ( 0x0100 ), "c" ( 0x2000 ) );
 }
 
@@ -243,7 +235,6 @@ static void bios_putchar ( int character ) {
 
        /* Print character with attribute */
        __asm__ __volatile__ ( REAL_CODE ( "pushl %%ebp\n\t" /* gcc bug */
-                                          "sti\n\t"
                                           /* Skip non-printable characters */
                                           "cmpb $0x20, %%al\n\t"
                                           "jb 1f\n\t"
@@ -264,7 +255,6 @@ static void bios_putchar ( int character ) {
                                           "xorw %%bx, %%bx\n\t"
                                           "movb $0x0e, %%ah\n\t"
                                           "int $0x10\n\t"
-                                          "cli\n\t"
                                           "popl %%ebp\n\t" /* gcc bug */ )
                               : "=a" ( discard_a ), "=b" ( discard_b ),
                                 "=c" ( discard_c )