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authorAnthony Liguori <aliguori@us.ibm.com>2013-07-23 10:57:04 -0500
committerAnthony Liguori <aliguori@us.ibm.com>2013-07-23 10:57:04 -0500
commit3988982c82ad4173dea376fea30e5432d36146db (patch)
treea4f72b53b9db680859ecc16b43dae4f113e1b744 /HACKING
parent931f0adf64261bf7eb3efaafb4430c04a6a3e6f6 (diff)
parent6f152e9bc80aed81ea89aa8ad345cd71326b71fb (diff)
Merge remote-tracking branch 'afaerber/tags/qom-cpu-for-anthony' into staging
QOM CPUState refactorings * Fix NULL pointer dereference in gdbstub * Introduce vaddr type * Introduce CPUClass::set_pc() * Introduce CPUClass::synchronize_from_tb() * Introduce CPUClass::get_phys_page_debug() * Introduce CPUClass::memory_rw_debug() * Move singlestep_enabled and gdb_regs fields out of CPU_COMMON * Adopt CPUState in more APIs * Propagate CPUState in gdbstub # gpg: Signature made Mon 22 Jul 2013 07:50:17 PM CDT using RSA key ID 3E7E013F # gpg: Can't check signature: public key not found # By Andreas Färber (21) and others # Via Andreas Färber * afaerber/tags/qom-cpu-for-anthony: (24 commits) linux-user: Use X86CPU property to retrieve CPUID family gdbstub: Change gdb_register_coprocessor() argument to CPUState cpu: Move gdb_regs field from CPU_COMMON to CPUState gdbstub: Change GDBState::{c,g}_cpu and find_cpu() to CPUState cpu: Introduce CPUClass::memory_rw_debug() for target_memory_rw_debug() exec: Change cpu_memory_rw_debug() argument to CPUState cpu: Turn cpu_get_phys_page_debug() into a CPUClass hook gdbstub: Change gdb_{read,write}_register() argument to CPUState gdbstub: Change gdb_handlesig() argument to CPUState gdbstub: Change syscall callback argument to CPUState kvm: Change kvm_{insert,remove}_breakpoint() argument to CPUState cpu: Change cpu_single_step() argument to CPUState gdbstub: Update gdb_handlesig() and gdb_signalled() Coding Style cpu: Move singlestep_enabled field from CPU_COMMON to CPUState target-alpha: Copy implver to DisasContext target-alpha: Copy singlestep_enabled to DisasContext cpu: Introduce CPUClass::synchronize_from_tb() for cpu_pc_from_tb() target-unicore32: Implement CPUClass::set_pc() target-moxie: Implement CPUClass::set_pc() target-m68k: Implement CPUClass::set_pc() ...
Diffstat (limited to 'HACKING')
-rw-r--r--HACKING19
1 files changed, 17 insertions, 2 deletions
diff --git a/HACKING b/HACKING
index e73ac79fe9..12fbc8afe4 100644
--- a/HACKING
+++ b/HACKING
@@ -40,8 +40,23 @@ speaking, the size of guest memory can always fit into ram_addr_t but
it would not be correct to store an actual guest physical address in a
ram_addr_t.
-Use target_ulong (or abi_ulong) for CPU virtual addresses, however
-devices should not need to use target_ulong.
+For CPU virtual addresses there are several possible types.
+vaddr is the best type to use to hold a CPU virtual address in
+target-independent code. It is guaranteed to be large enough to hold a
+virtual address for any target, and it does not change size from target
+to target. It is always unsigned.
+target_ulong is a type the size of a virtual address on the CPU; this means
+it may be 32 or 64 bits depending on which target is being built. It should
+therefore be used only in target-specific code, and in some
+performance-critical built-per-target core code such as the TLB code.
+There is also a signed version, target_long.
+abi_ulong is for the *-user targets, and represents a type the size of
+'void *' in that target's ABI. (This may not be the same as the size of a
+full CPU virtual address in the case of target ABIs which use 32 bit pointers
+on 64 bit CPUs, like sparc32plus.) Definitions of structures that must match
+the target's ABI must use this type for anything that on the target is defined
+to be an 'unsigned long' or a pointer type.
+There is also a signed version, abi_long.
Of course, take all of the above with a grain of salt. If you're about
to use some system interface that requires a type like size_t, pid_t or