diff --git a/plat/pc86/README b/plat/pc86/README index 689c70844..dcbe0ba27 100644 --- a/plat/pc86/README +++ b/plat/pc86/README @@ -23,6 +23,9 @@ are stubs required to make the demo apps link. File descriptors 0, 1 and 2 represent the console. All reads block. There's enough TTY emulation to allow \n conversion and local echo (but it can't be turned off). +Console output is echoed to the serial port (without any setup). This is used +by qemu for running tests. + Example command line ==================== diff --git a/plat/pc86/libsys/_sys_rawwrite.s b/plat/pc86/libsys/_sys_rawwrite.s index 75f75aae1..ae477c6d2 100644 --- a/plat/pc86/libsys/_sys_rawwrite.s +++ b/plat/pc86/libsys/_sys_rawwrite.s @@ -21,9 +21,18 @@ __sys_rawwrite: push bp mov bp, sp + ! Write to the BIOS console. + movb al, 4(bp) movb ah, 0x0E mov bx, 0x0007 int 0x10 + + ! Also write to the serial port (used by the test suite). + + movb ah, 0x01 + xor dx, dx + int 0x14 + jmp .cret \ No newline at end of file