target/openrisc: implement shadow registers

Shadow registers are part of the openrisc spec along with sr[cid], as
part of the fast context switching feature.  When exceptions occur,
instead of having to save registers to the stack if enabled the CID will
increment and a new set of registers will be available.

This patch only implements shadow registers which can be used as extra
scratch registers via the mfspr and mtspr if required.  This is
implemented in a way where it would be easy to add on the fast context
switching, currently cid is hardcoded to 0.

This is need for openrisc linux smp kernels to boot correctly.

Signed-off-by: Stafford Horne <shorne@gmail.com>
11 files changed
tree: 1aa8a808dd445d9f57a65affc72a3b03d3e93cbe
  1. audio/
  2. backends/
  3. block/
  4. bsd-user/
  5. chardev/
  6. contrib/
  7. crypto/
  8. default-configs/
  9. disas/
  10. docs/
  11. fpu/
  12. fsdev/
  13. gdb-xml/
  14. hw/
  15. include/
  16. io/
  17. libdecnumber/
  18. linux-headers/
  19. linux-user/
  20. migration/
  21. nbd/
  22. net/
  23. pc-bios/
  24. po/
  25. qapi/
  26. qga/
  27. qobject/
  28. qom/
  29. replay/
  30. roms/
  31. scripts/
  32. slirp/
  33. stubs/
  34. target/
  35. tcg/
  36. tests/
  37. trace/
  38. ui/
  39. util/
  40. .dir-locals.el
  41. .exrc
  42. .gitignore
  43. .gitmodules
  44. .mailmap
  45. .shippable.yml
  46. .travis.yml
  47. accel.c
  48. arch_init.c
  49. atomic_template.h
  50. balloon.c
  51. block.c
  52. blockdev-nbd.c
  53. blockdev.c
  54. blockjob.c
  55. bootdevice.c
  56. bt-host.c
  57. bt-vhci.c
  58. Changelog
  59. CODING_STYLE
  60. configure
  61. COPYING
  62. COPYING.LIB
  63. cpu-exec-common.c
  64. cpu-exec.c
  65. cpus-common.c
  66. cpus.c
  67. cputlb.c
  68. device-hotplug.c
  69. device_tree.c
  70. disas.c
  71. dma-helpers.c
  72. dump.c
  73. exec.c
  74. gdbstub.c
  75. HACKING
  76. hax-stub.c
  77. hmp-commands-info.hx
  78. hmp-commands.hx
  79. hmp.c
  80. hmp.h
  81. ioport.c
  82. iothread.c
  83. kvm-all.c
  84. kvm-stub.c
  85. LICENSE
  86. MAINTAINERS
  87. Makefile
  88. Makefile.objs
  89. Makefile.target
  90. memory.c
  91. memory_ldst.inc.c
  92. memory_mapping.c
  93. module-common.c
  94. monitor.c
  95. numa.c
  96. os-posix.c
  97. os-win32.c
  98. page_cache.c
  99. qapi-schema.json
  100. qdev-monitor.c
  101. qdict-test-data.txt
  102. qemu-bridge-helper.c
  103. qemu-doc.texi
  104. qemu-ga.texi
  105. qemu-img-cmds.hx
  106. qemu-img.c
  107. qemu-img.texi
  108. qemu-io-cmds.c
  109. qemu-io.c
  110. qemu-nbd.c
  111. qemu-nbd.texi
  112. qemu-option-trace.texi
  113. qemu-options-wrapper.h
  114. qemu-options.h
  115. qemu-options.hx
  116. qemu-seccomp.c
  117. qemu-tech.texi
  118. qemu.nsi
  119. qemu.sasl
  120. qmp.c
  121. qtest.c
  122. README
  123. replication.c
  124. replication.h
  125. rules.mak
  126. softmmu_template.h
  127. spice-qemu-char.c
  128. tcg-runtime.c
  129. tci.c
  130. thunk.c
  131. tpm.c
  132. trace-events
  133. translate-all.c
  134. translate-all.h
  135. translate-common.c
  136. user-exec-stub.c
  137. user-exec.c
  138. VERSION
  139. version.rc
  140. vl.c
  141. xen-common-stub.c
  142. xen-common.c
  143. xen-hvm-stub.c
  144. xen-hvm.c
  145. xen-mapcache.c