Introduce hwpatcher, a tool to patch binaries

This tool is a scriptable (lua) tool to patch binaries, it supports:
- raw binary
- ELF
- SB(v1/v2)
It also contains some basic routines to parse and generate useful arm/thumb code
like jump or register load/store. This is very useful to take a firmware and
patch an interrupt vector or some code to jump to an extra payload added to
the binary. Examples are provided for several STMP based target which the payload
is expected to be hwstub, and also for the Sansa View. A typical patcher usually
requires three elements:
- the lua patcher itself
- the payload (hwstub for example)
- (optional) a small stub either to jump properly to the payload or determine
  under which circumstance to do the jump (hold a key for example)

Change-Id: I6d36020a3bc9e636615ac8221b7591ade5f251e3

1 files changed, 87 insertions, 0 deletions

diff --git a/utils/hwpatcher/patch.S b/utils/hwpatcher/patch.S
new file mode 100644
index 0000000..6c27e29
--- /dev/null
+++ b/utils/hwpatcher/patch.S
@@ -0,0 +1,87 @@
+.text
+.global _start
+_start:
+    b       exec
+branch_addr:
+    .word   kill
+hw_power_sts:
+#if defined(CREATIVE_ZEN)
+    .word   0x800440b0 /* STMP3700 */
+#else
+    .word   0x800440c0 /* IMX233 */
+#endif
+hw_pinctrl_din0:
+    .word   0x80018600
+hw_pinctrl_din1:
+    .word   0x80018610
+hw_pinctrl_din2:
+    .word   0x80018620
+kill:
+    ldr     pc, branch_addr
+exec:
+#if defined(SANSA_FUZEPLUS)
+    /* check PSWITCH=1 (power button pressed) */
+    ldr     r0, hw_power_sts
+    ldr     r0, [r0]
+    mov     r0, r0, lsr #20
+    and     r0, #3
+    cmp     r0, #1
+    bne     ret
+    /* check B1P30=0 (volume down pressed) */
+    ldr     r0, hw_pinctrl_din1
+    ldr     r0, [r0]
+    mov     r0, r0, lsr #30
+    ands    r0, #1
+    beq     kill
+#elif defined(CREATIVE_ZENXFI3)
+    /* check PSWITCH=1 (power button pressed) */
+    ldr     r0, hw_power_sts
+    ldr     r0, [r0]
+    mov     r0, r0, lsr #20
+    and     r0, #3
+    cmp     r0, #1
+    bne     ret
+    /* check B2P07=0 (volume down pressed) */
+    ldr     r0, hw_pinctrl_din2
+    ldr     r0, [r0]
+    mov     r0, r0, lsr #7
+    ands    r0, #1
+    beq     kill
+#elif defined(CREATIVE_ZENXFI2)
+    /* check B0P11=0 (power button pressed) and B0P14 (select button pressed) */
+    ldr     r0, hw_pinctrl_din0
+    ldr     r0, [r0]
+    mov     r0, r0, lsr #11
+    tst     r0, #1
+    bne     ret
+    mov     r0, r0, lsr #3
+    tst     r0, #1
+    beq     kill
+#elif defined(CREATIVE_ZEN)
+    /* check PSWITCH=1 (power button pressed) */
+    ldr     r0, hw_power_sts
+    ldr     r0, [r0]
+    mov     r0, r0, lsr #18
+    and     r0, #3
+    cmp     r0, #0
+    bne     kill
+#elif defined(SONY_NWZ)
+    /* check PSWITCH=3 (power button pressed) */
+    ldr     r0, hw_power_sts
+    ldr     r0, [r0]
+    mov     r0, r0, lsr #20
+    and     r0, #3
+    cmp     r0, #3
+    beq     kill
+#elif defined(CREATIVE_ZENXFISTYLE)
+    /* check PSWITCH=1 (power button pressed) */
+    ldr     r0, hw_power_sts
+    ldr     r0, [r0]
+    mov     r0, r0, lsr #20
+    and     r0, #3
+    cmp     r0, #1
+    beq     kill
+#else
+#error implement me
+#endif
+ret:
\ No newline at end of file