[08/43] semihosting: Generalize GuestFDFeatureFile

Commit Message

Richard Henderson April 30, 2022, 1:28 p.m. UTC

Rather than hard-coding the buffer from which we deliver data,
pass it in on initialization.  This decouples the feature from
ARM semihosting.

Signed-off-by: Richard Henderson <[e-mail]>
---
 include/semihosting/guestfd.h | 10 ++++++---
 semihosting/arm-compat-semi.c | 39 ++++++++++++++++++-----------------
 semihosting/guestfd.c         |  8 ++++---
 3 files changed, 32 insertions(+), 25 deletions(-)

Patch

diff --git a/include/semihosting/guestfd.h b/include/semihosting/guestfd.h
index 5d6e744305..5aa2722cb2 100644
--- a/include/semihosting/guestfd.h
+++ b/include/semihosting/guestfd.h
@@ -15,7 +15,7 @@  typedef enum GuestFDType {
     GuestFDUnused = 0,
     GuestFDHost = 1,
     GuestFDGDB = 2,
-    GuestFDFeatureFile = 3,
+    GuestFDStatic = 3,
 } GuestFDType;
 
 /*
@@ -26,7 +26,11 @@  typedef struct GuestFD {
     GuestFDType type;
     union {
         int hostfd;
-        unsigned featurefile_offset;
+        struct {
+            const uint8_t *data;
+            size_t len;
+            size_t off;
+        } staticfile;
     };
 } GuestFD;
 
@@ -35,6 +39,6 @@  void dealloc_guestfd(int guestfd);
 GuestFD *get_guestfd(int guestfd);
 
 void associate_guestfd(int guestfd, int hostfd);
-void init_featurefile_guestfd(int guestfd);
+void staticfile_guestfd(int guestfd, const uint8_t *data, size_t len);
 
 #endif /* SEMIHOSTING_GUESTFD_H */
diff --git a/semihosting/arm-compat-semi.c b/semihosting/arm-compat-semi.c
index c092138031..c6bfd4d1ba 100644
--- a/semihosting/arm-compat-semi.c
+++ b/semihosting/arm-compat-semi.c
@@ -553,13 +553,13 @@  static const uint8_t featurefile_data[] = {
     SH_EXT_EXIT_EXTENDED | SH_EXT_STDOUT_STDERR, /* Feature byte 0 */
 };
 
-static uint32_t featurefile_closefn(CPUState *cs, GuestFD *gf)
+static uint32_t staticfile_closefn(CPUState *cs, GuestFD *gf)
 {
     /* Nothing to do */
     return 0;
 }
 
-static uint32_t featurefile_writefn(CPUState *cs, GuestFD *gf,
+static uint32_t staticfile_writefn(CPUState *cs, GuestFD *gf,
                                     target_ulong buf, uint32_t len)
 {
     /* This fd can never be open for writing */
@@ -568,7 +568,7 @@  static uint32_t featurefile_writefn(CPUState *cs, GuestFD *gf,
     return set_swi_errno(cs, -1);
 }
 
-static uint32_t featurefile_readfn(CPUState *cs, GuestFD *gf,
+static uint32_t staticfile_readfn(CPUState *cs, GuestFD *gf,
                                    target_ulong buf, uint32_t len)
 {
     CPUArchState *env = cs->env_ptr;
@@ -582,11 +582,11 @@  static uint32_t featurefile_readfn(CPUState *cs, GuestFD *gf,
     }
 
     for (i = 0; i < len; i++) {
-        if (gf->featurefile_offset >= sizeof(featurefile_data)) {
+        if (gf->staticfile.off >= gf->staticfile.len) {
             break;
         }
-        s[i] = featurefile_data[gf->featurefile_offset];
-        gf->featurefile_offset++;
+        s[i] = gf->staticfile.data[gf->staticfile.off];
+        gf->staticfile.off++;
     }
 
     unlock_user(s, buf, len);
@@ -595,21 +595,21 @@  static uint32_t featurefile_readfn(CPUState *cs, GuestFD *gf,
     return len - i;
 }
 
-static uint32_t featurefile_isattyfn(CPUState *cs, GuestFD *gf)
+static uint32_t staticfile_isattyfn(CPUState *cs, GuestFD *gf)
 {
     return 0;
 }
 
-static uint32_t featurefile_seekfn(CPUState *cs, GuestFD *gf,
+static uint32_t staticfile_seekfn(CPUState *cs, GuestFD *gf,
                                    target_ulong offset)
 {
-    gf->featurefile_offset = offset;
+    gf->staticfile.off = offset;
     return 0;
 }
 
-static uint32_t featurefile_flenfn(CPUState *cs, GuestFD *gf)
+static uint32_t staticfile_flenfn(CPUState *cs, GuestFD *gf)
 {
-    return sizeof(featurefile_data);
+    return gf->staticfile.len;
 }
 
 typedef struct GuestFDFunctions {
@@ -638,13 +638,13 @@  static const GuestFDFunctions guestfd_fns[] = {
         .seekfn = gdb_seekfn,
         .flenfn = gdb_flenfn,
     },
-    [GuestFDFeatureFile] = {
-        .closefn = featurefile_closefn,
-        .writefn = featurefile_writefn,
-        .readfn = featurefile_readfn,
-        .isattyfn = featurefile_isattyfn,
-        .seekfn = featurefile_seekfn,
-        .flenfn = featurefile_flenfn,
+    [GuestFDStatic] = {
+        .closefn = staticfile_closefn,
+        .writefn = staticfile_writefn,
+        .readfn = staticfile_readfn,
+        .isattyfn = staticfile_isattyfn,
+        .seekfn = staticfile_seekfn,
+        .flenfn = staticfile_flenfn,
     },
 };
 
@@ -765,7 +765,8 @@  target_ulong do_common_semihosting(CPUState *cs)
                 errno = EACCES;
                 return set_swi_errno(cs, -1);
             }
-            init_featurefile_guestfd(guestfd);
+            staticfile_guestfd(guestfd, featurefile_data,
+                               sizeof(featurefile_data));
             return guestfd;
         }
 
diff --git a/semihosting/guestfd.c b/semihosting/guestfd.c
index e77265db0f..b6405f5663 100644
--- a/semihosting/guestfd.c
+++ b/semihosting/guestfd.c
@@ -94,13 +94,15 @@  void associate_guestfd(int guestfd, int hostfd)
     gf->hostfd = hostfd;
 }
 
-void init_featurefile_guestfd(int guestfd)
+void staticfile_guestfd(int guestfd, const uint8_t *data, size_t len)
 {
     GuestFD *gf = do_get_guestfd(guestfd);
 
     assert(gf);
-    gf->type = GuestFDFeatureFile;
-    gf->featurefile_offset = 0;
+    gf->type = GuestFDStatic;
+    gf->staticfile.data = data;
+    gf->staticfile.len = len;
+    gf->staticfile.off = 0;
 }
 
 /*