target/xtensa: add linux-user support

Import list of syscalls from the kernel source. Conditionalize code/data
that is only used with softmmu. Implement exception handlers. Implement
signal hander (only the core registers for now, no coprocessors or TIE).

Cc: Riku Voipio <riku.voipio@iki.fi>
Cc: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

1 files changed, 58 insertions, 0 deletions

diff --git a/linux-user/elfload.c b/linux-user/elfload.c
index 5fc130cc20..fe7a5bc566 100644
--- a/linux-user/elfload.c
+++ b/linux-user/elfload.c
@@ -1341,6 +1341,64 @@ static inline void init_thread(struct target_pt_regs *regs,
 
 #endif /* TARGET_HPPA */
 
+#ifdef TARGET_XTENSA
+
+#define ELF_START_MMAP 0x20000000
+
+#define ELF_CLASS       ELFCLASS32
+#define ELF_ARCH        EM_XTENSA
+
+static inline void init_thread(struct target_pt_regs *regs,
+                               struct image_info *infop)
+{
+    regs->windowbase = 0;
+    regs->windowstart = 1;
+    regs->areg[1] = infop->start_stack;
+    regs->pc = infop->entry;
+}
+
+/* See linux kernel: arch/xtensa/include/asm/elf.h.  */
+#define ELF_NREG 128
+typedef target_elf_greg_t target_elf_gregset_t[ELF_NREG];
+
+enum {
+    TARGET_REG_PC,
+    TARGET_REG_PS,
+    TARGET_REG_LBEG,
+    TARGET_REG_LEND,
+    TARGET_REG_LCOUNT,
+    TARGET_REG_SAR,
+    TARGET_REG_WINDOWSTART,
+    TARGET_REG_WINDOWBASE,
+    TARGET_REG_THREADPTR,
+    TARGET_REG_AR0 = 64,
+};
+
+static void elf_core_copy_regs(target_elf_gregset_t *regs,
+                               const CPUXtensaState *env)
+{
+    unsigned i;
+
+    (*regs)[TARGET_REG_PC] = tswapreg(env->pc);
+    (*regs)[TARGET_REG_PS] = tswapreg(env->sregs[PS] & ~PS_EXCM);
+    (*regs)[TARGET_REG_LBEG] = tswapreg(env->sregs[LBEG]);
+    (*regs)[TARGET_REG_LEND] = tswapreg(env->sregs[LEND]);
+    (*regs)[TARGET_REG_LCOUNT] = tswapreg(env->sregs[LCOUNT]);
+    (*regs)[TARGET_REG_SAR] = tswapreg(env->sregs[SAR]);
+    (*regs)[TARGET_REG_WINDOWSTART] = tswapreg(env->sregs[WINDOW_START]);
+    (*regs)[TARGET_REG_WINDOWBASE] = tswapreg(env->sregs[WINDOW_BASE]);
+    (*regs)[TARGET_REG_THREADPTR] = tswapreg(env->uregs[THREADPTR]);
+    xtensa_sync_phys_from_window((CPUXtensaState *)env);
+    for (i = 0; i < env->config->nareg; ++i) {
+        (*regs)[TARGET_REG_AR0 + i] = tswapreg(env->phys_regs[i]);
+    }
+}
+
+#define USE_ELF_CORE_DUMP
+#define ELF_EXEC_PAGESIZE       4096
+
+#endif /* TARGET_XTENSA */
+
 #ifndef ELF_PLATFORM
 #define ELF_PLATFORM (NULL)
 #endif