From 6ee18643770b360da0c8ee44aa07708caa516fa9 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Mon, 16 Sep 2019 15:15:44 +0100 Subject: [PATCH] target/arm/arm-semi: Implement SH_EXT_STDOUT_STDERR extension MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit SH_EXT_STDOUT_STDERR is a v2.0 semihosting extension: the guest can open ":tt" with a file mode requesting append access in order to open stderr, in addition to the existing "open for read for stdin or write for stdout". Implement this and report it via the :semihosting-features data. Signed-off-by: Peter Maydell Reviewed-by: Alex Bennée Message-id: 20190916141544.17540-16-peter.maydell@linaro.org --- target/arm/arm-semi.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) diff --git a/target/arm/arm-semi.c b/target/arm/arm-semi.c index f65d8c907e..6f7b6d801b 100644 --- a/target/arm/arm-semi.c +++ b/target/arm/arm-semi.c @@ -516,13 +516,14 @@ static uint32_t gdb_flenfn(ARMCPU *cpu, GuestFD *gf) /* Feature bits reportable in feature byte 0 */ #define SH_EXT_EXIT_EXTENDED (1 << 0) +#define SH_EXT_STDOUT_STDERR (1 << 1) static const uint8_t featurefile_data[] = { SHFB_MAGIC_0, SHFB_MAGIC_1, SHFB_MAGIC_2, SHFB_MAGIC_3, - SH_EXT_EXIT_EXTENDED, /* Feature byte 0 */ + SH_EXT_EXIT_EXTENDED | SH_EXT_STDOUT_STDERR, /* Feature byte 0 */ }; static void init_featurefile_guestfd(int guestfd) @@ -710,7 +711,21 @@ target_ulong do_arm_semihosting(CPUARMState *env) } if (strcmp(s, ":tt") == 0) { - int result_fileno = arg1 < 4 ? STDIN_FILENO : STDOUT_FILENO; + int result_fileno; + + /* + * We implement SH_EXT_STDOUT_STDERR, so: + * open for read == stdin + * open for write == stdout + * open for append == stderr + */ + if (arg1 < 4) { + result_fileno = STDIN_FILENO; + } else if (arg1 < 8) { + result_fileno = STDOUT_FILENO; + } else { + result_fileno = STDERR_FILENO; + } associate_guestfd(guestfd, result_fileno); unlock_user(s, arg0, 0); return guestfd;