arm-linux stub interfacing for lzma

src/stub/arm-linux.kernel.vmlinux-head.h

@@ -1,5 +1,5 @@
 /* arm-linux.kernel.vmlinux-head.h
-   created from arm-linux.kernel.vmlinux-head.bin, 20 (0x14) bytes
+   created from arm-linux.kernel.vmlinux-head.bin, 68 (0x44) bytes
 
    This file is part of the UPX executable compressor.
 
@@ -28,11 +28,14 @@
  */
 
 
-#define STUB_ARM_LINUX_KERNEL_VMLINUX_HEAD_SIZE    20
-#define STUB_ARM_LINUX_KERNEL_VMLINUX_HEAD_ADLER32 0x621b0b3f
-#define STUB_ARM_LINUX_KERNEL_VMLINUX_HEAD_CRC32   0x87e74167
+#define STUB_ARM_LINUX_KERNEL_VMLINUX_HEAD_SIZE    68
+#define STUB_ARM_LINUX_KERNEL_VMLINUX_HEAD_ADLER32 0xd30518ac
+#define STUB_ARM_LINUX_KERNEL_VMLINUX_HEAD_CRC32   0xa10e8134
 
-unsigned char stub_arm_linux_kernel_vmlinux_head[20] = {
-112,  0, 32,225,  1, 96, 34,233,  2,208,160,225,254,255,255,235,   /* 0x   0 */
-  2,160,157,232                                                    /* 0x  10 */
+unsigned char stub_arm_linux_kernel_vmlinux_head[68] = {
+  9, 96, 34,233,  2,208,160,225,  0, 32,160,225, 36,  0,143,226,   /* 0x   0 */
+ 10, 16,176,232,  4, 48, 45,229, 13, 48,160,225,  4,192, 45,229,   /* 0x  10 */
+254,255,255,235,  0,  0, 80,227,  7,  0,  0, 26, 14,112,157,232,   /* 0x  20 */
+  3,  0,130,224, 14,240,160,225,  0,  0,  0,  0,  0,  0,  0,  0,   /* 0x  30 */
+  0,  0,  0,  0                                                    /* 0x  40 */
 };

src/stub/src/arm-linux.kernel.vmlinux-head.S

@@ -28,12 +28,27 @@
 /* Calling sequence of equivalent code in arch/arm/boot/compressed/misc.c:
 decompress_kernel:  # (char *out, char *tmp, char *end_tmp, int arch_id)
 */
-        bkpt
-        stmdb r2!,{r0,sp,lr}
-        mov sp,r2
-// PackVmlinuxARM::pack knows the format of the next instruction.
-        bl COMPRESSED_LENGTH
-        ldmia sp,{r1,sp,pc}
+        stmdb r2!,{r0,r3,sp,lr}  // &outdata, arch_id, sp_in, retaddr
+        mov sp,r2  // switch stacks to end_tmp area (64KB)
+        mov r2,r0  // &outdata
+        adr r0,.L10
+        ldmia r0!,{r1,r3,ip}  // r0=&indata; r1=insize; r3=outsize; ip=method
+        str r3,[sp,#-4]!  // outsize
+        mov r3,sp  // &outsize
+        str ip,[sp,#-4]!  // method
+// PackVmlinuxARM::pack knows the layout of the following words.
+        bl LINUX000  // (&indata, insize, &outdata, &outsize, method)
+spin:
+        cmp r0,#0  // check for success
+        bne spin
+
+        ldmia sp,{r1,r2,r3,ip,sp,lr}  // method, outsize, &outdata, arch_id, sp_in, retaddr
+        add r0,r2,r3  // rv= &outdata[outsize]
+        mov pc,lr  // return
+.L10:
+        .long   COMPRESSED_LENGTH
+        .long UNCOMPRESSED_LENGTH
+        .long METHOD
 
 // Compressed data appears >here<, then decompressor.
 

src/stub/src/arm-linux.kernel.vmlinux.S

@@ -37,29 +37,18 @@
 ; ============= ENTRY POINT
 ; =============
 
-;  In:
-;    r0= outptr; r1= &tmp; r3= arch_id; lr= retaddr, inptr - N
-
   How to debug: run under qemu (http://fabrice.bellard.free.fr/qemu/)
   after un-commenting the  bkpt  opcode below.  That opcode forces qemu
   to stop in gdb.  You'll have to "set $pc+=4" by hand.
 */
 section         LINUX000
-        bkpt  // qemu breakpoint
-        ldr r1,[lr,#-4]  // 'bl' instruction
-        str r3,[sp,$-4]!  // push arch_id
-        bic r1,r1,#~0<<24  // word count
-        sub sp,sp,#4  // space for outsize
-        mov r1,r1,lsl #2  // byte count
-        mov r3,sp  // &outsize
-        .long 0xe2411000 + BYTE_ADJ  // sub r1,r1,#BYTE_ADJ  // insize
-        mov r2,r0  // outptr
-        .long 0xe28e0000 + WORD_ADJ  // add r0,lr,#WORD_ADJ  // inptr
+        // bkpt  // qemu DEBUG only
 /*
   r0= inptr
   r1= insize
   r2= outptr
   r3= &outsize
+  sp/ method
 */
 
 section         LXCALLT1